THE MARIJUANA GROWER'S GUIDE..........by Mel Frank & Ed RosenthalTHE MARIJUANA GROWER'S GUIDE
by Mel Frank and Ed Rosenthal
Typed by Ben Dawson
Revised 1992
NOTE:- Footnotes have been placed in double brackets (()). Numbers throughout 
refer to bibliography and are sometimes in brackets, sometimes they aren't. All 
dates are for northern hemisphere only. Comments on pictures are in curly 
brackets {}. Please distribute this widely so we can all smoke better marijuana. 
Legalise marijuana.
4 October 1996
Copying this book was a megamission that took about 3 weeks in the September of 
1993. Everything in the book has been copied - even the bibliography. The online 
version of this guide is available at: http://www.iinet.net.au/~ben/Guide (No 
Longer Exists) 
Ben Dawson
ben@iinet.net.au
January 1998
Hyperlinks were added throughout the document for easy navigation. Also the text 
was formated to be more readable. Alonso Acua.
August 1999
This File is currently available at http://www.mellowgold.com/grow 
As far as we are aware, it's the only place online to find it, please distribute 
this file freely. 
CONTENTS 
Foreword
Preface
History and Taxonomy of Cannabis                        [1]
Cannabis and Ancient History                            [1.2]
Cannabis and American History                           [1.3]
Cannabis and: Species or Varieties                      [1.4]

Cannabinoids : The Active Ingredients of Marijuana      [2]
Cannabinoids and the High                               [2.2]
Resin and Resin Glands                                  [2.3]
Production of Cannabinoids by Cannabis                  [2.4]
Cannabis Chemotypes                                     [2.5]

Before Cultivation Begins                               [3]
Choosing Seeds                                          [3.2]
Cannabis Life Cycle                                     [3.3]
Photoperiod and Flowering                               [3.4]
Inherent Variations in Potency                          [3.5]
Cultivation: Indoors or Outdoors?                       [3.6]

         Indoor Gardening

Introduction                                            [4]

Artificial Light                                        [5]
Features                                                [5.2]
Sources                                                 [5.3]
Setting up the Garden                                   [5.4]
Electricity                                             [5.5]

Soil and Containers for it                              [6]
Pots and Other Containers                               [6.2]
Properties of Soil                                      [6.3]
Preparing Commercial Soils and Mixers                   [6.4]
Buying Soil Components                                  [6.5]
Digging Soil                                            [6.6]
Growing Methods                                         [6.7]

Maintaining the Correct Environment                     [7]
Requirements for Germination                            [7.2]
Light Cycle and Distance of Lights from Plants          [7.3]
Water                                                   [7.4]
Air                                                     [7.5]
Humidity                                                [7.6]

Gardening Techniques                                    [8]
Thinning                                                [8.2]
Transplanting                                           [8.3]
Supports for Plants                                     [8.4]
Uniform Growth                                          [8.5]
Pruning                                                 [8.6]
Training                                                [8.7]

Nutrients and Fertilising                               [9]
Nutrients                                               [9.2]
Application: Fertilising                                [9.3]
Nutrient Deficiencies                                   [9.4]
Soilless Mixtures                                       [9.5]

Diseases and Plant Pests                                [10]
Microbial Diseases                                      [10.2]
Nutrient Diseases                                       [10.3]
Plant Pests                                             [10.4]

Maintenance and Restarting                              [11]

      Outdoor Cultivation

Choosing a Site                                         [12]
Where to Grow                                           [12.2]
Light                                                   [12.3]

Soil                                                    [13]
Types of Soil                                           [13.2]
Humus and Composts                                      [13.3]
Texture                                                 [13.4]
pH                                                      [13.5]
Fertilisers                                             [13.6]
Techniques for Preparing Soils                          [13.7]
Guerrilla Farming                                       [13.8]

Planting and Transplanting                              [14]
When to Plant                                           [14.2]
Preparing to Sow                                        [14.3]
Germination                                             [14.4]
Transplanting                                           [14.5]

Caring for the Growing Plants                           [15]
Weeding                                                 [15.2]
Watering                                                [15.3]
Thinning                                                [15.4]
Staking                                                 [15.5]
Pruning                                                 [15.6]
Gardening Tips                                          [15.7]

Insects and Other Pests                                 [16]
Biological Control                                      [16.2]
Chemical Insecticides                                   [16.3]
Common Pests                                            [16.4]
Vertebrate Pests                                        [16.5]

           Flowering, Breeding and Propagation

Genetics and Sex in Cannabis                            [17]
Flowering                                               [17.2]
Sexual Variants in Cannabis                             [17.3]
Sexing the Plants                                       [17.4]
Sinsemilla                                              [17.5]

Propagation and Breeding                                [18]
Producing Seeds                                         [18.2]
Producing Female Seeds                                  [18.3]
Breeding                                                [18.4]
Cuttings                                                [18.5]
Grafting                                                [18.6]
Polyploids                                              [18.7]

Effects of the Environment on Potency                   [19]
Stress                                                  [19.2]
Nutrients                                               [19.3]

          Harvesting, Curing and Drying

Harvesting                                              [20]
Harvesting During Growth: Leaves and Growing Shoots	[20.2]
Male Plants                                             [20.3]
Harvesting Female Buds                                  [20.4]
Weather                                                 [20.5]
Potency and Decomposition                               [20.6]
Timing the Harvest                                      [20.7]
Final Harvest                                           [20.8]

After the Harvest                                       [21]
Stripping                                               [21.2]
Grading and Manicuring                                  [21.3]
Curing                                                  [21.4]
Drying                                                  [21.5]
Fermentation                                            [21.6]
Storage                                                 [21.7]


Bibliography                                            [22]

FOREWORD
Marijuana, or cannabis as it is known internationally, is a plant whose presence 
is almost universal in our world today. Conservative international reports 
estimate that there are now 300 million cannabis users. Recent reports indicate 
that 10 percent of the adult population in the United States are regular users, 
a figure which is probably similar for many countries in Europe. Its use is also 
widespread in Africa, Asia, many Arab nations, parts of South America and the 
Caribbean, as well as Australia and New Zealand. In 1978, more than 5.2 million 
kilograms (12 million pounds) of cannabis were seized by police worldwide. 
Authorities estimated that this did not exceed 10 percent of the total traffic. 
What has been the response of officials around the world to the use of this 
plant by its citizens? Regrettably, the climate has been one of almost universal 
repression, hostility and open violence. Despite gains made in the United States 
and Europe throughout the 1970's, a new wave of ignorance regarding the use of 
this plant seems to be sweeping the world. Predictably, the United States has 
sought to export this "neo-Reefer Madness" to other countries. A united Nations 
sub-commission of drug enforcement officials in the Far East released a report 
some time ago extremely critical of the efforts of some countries to 
decriminalize (i.e. remove criminal penalties for possession of a small amount) 
cannabis. The sub-commission stated that any such reduction of penalties would 
vastly increase use, and strongly urged that all countries continue to keep 
strict laws on the books even for possession of cannabis1. Others requested that 
publicity campaign be conducted in the media against cannabis, and that more 
funding be given to "scientific" work to prove that cannabis was harmful2. 
US officials, alarmed by reports of cannabis use among adolescents (which, 
although undesirably high, is in fact leveling off), and by political pressure 
from reactionary elements, have attempted to depict cannabis as the greatest 
threat since the atomic bomb. The results of this new hysteria have been great 
confusion among the public and a slowdown in the progress of cannabis law 
reform. The results have been predictable: in 1979, over 448,000 people were 
arrested in the USA for cannabis possession, 80 percent for simple possession. 
The estimated direct arrests cost to our increasingly debt-ridden government was 
over $600 million. But no one has ever attempted to account for the total cost 
of the immense law enforcement efforts against cannabis: for the salaries of 
Drug Enforcement Administration agents and federal and state narcotics agents 
and support personnel, the cost of incarcerating the thousands of people 
sentences to jail (estimated at 10 percent of the total arrests, or 48.000 
people), the costs of the anti-cannabis media campaign, the secret grants from 
NSA/CIA for cannabis eradications, and the economic cost to society created by 
turning law-abiding citizens into criminals. When these factors are taken into 
consideration, the cost goes into the billions. By contrast, in the eleven 
states which have enacted decriminalization since 1972, millions of dollars and 
hundreds of thousands of court, police and administrative work-hours have been 
saved. 
What can the concerned cannabis consumer do to end this climate of hysteria and 
ignorance? First, we must stress that cannabis legalisation would entail adult 
use only, and that social and legal restrictions on the use of cannabis would 
curtail, not increase, use by adolescents. Second, we must educate the public 
about the genuine effects of cannabis and stress moderate responsible use. This 
is what we stress about the user of society's legal drugs - alcohol, nicotine 
and caffeine, and we should take the same approach toward cannabis. Third, the 
public should be educated about the limits of the law and the rights of 
citizens; we should not seek to regulate private behaviour through the use of 
the criminal sanction. Laws protecting public safety, such as driving while 
under the influence of any substance, would still be kept on the books. 
However, as consumers we have an additional responsibility: we must begin to 
address the problems of supply and demand. It is essential that we take upon 
ourselves the task of proposing viable solutions to the current unworkable 
prohibition. 
With this is mind, numerous cannabis reform organizations around the world have 
begun exploring models for the legalization of cannabis. Under the auspices of 
the International Cannabis Alliance for Reform (ICAR), an international 
organization of cannabis law-reform groups, many of these organizations met in 
Amsterdam, Holland in February, 1980, at the first International Cannabis 
Legalization Conference to discuss legalization plans and proposals. The many 
plans presented reflected the various backgrounds and interests of the countries 
they represented some called for a totally open-market system run by 
cooperatives, others employed elaborate organizational systems with varying 
degrees of governmental control, and still others called for total control by 
the private sector. Emphasis was placed on the need for all groups to develop 
legalization models suited to their own particular climate and country and that 
a single, monolithic legalization plan was neither feasible nor desirable. 
However, virtually all the plans had one important element in common: every 
person would have the right to grow cannabis for his or her own personal use. 
This is the very minimum requirement upon which all legalisation models are 
based, for this would allow the consumer the chance to remove himself or herself 
from the black market, whether it be licit or illicit. 
This is an essential aspect of cannabis reform: to convince consumers to 
diversify their sources of supply by growing their own cannabis. Growing 
cannabis enables one to reduce drastically the costs and at the same time 
establish a closer relationship with the plant itself. Its amazing adaptability, 
acquired through centuries of travel to all four corners of the earth, users 
that it can grow and thrive anywhere there is sunlight and water. By learning 
the relatively simple techniques involved in cannabis horticulture, the consumer 
can avoid the illicit market with all its attendant problems, and concentrate on 
growing the plant itself, on producing and consuming the product of one's own 
labor, a product which is pure and can be produced at a cost of pennies per 
ounce. 
We must take this step, for just as the nations of the world are seeking energy, 
self-sufficiency, so now must we seek cannabis self-sufficiency. 
The willingness of consumers greatly to diversify their sources has caused 
tremendous changes in the manner in which cannabis is grown and marketed. 
Plagued by ridiculously high prices, dangers in purchasing, wild fluctuations in 
quantity and quality, impurities, and continual police harassment, consumers all 
over the world are discovering that anyone can grow good cannabis just about 
anywhere. 
In Central and South America, production has increased so rapidly in the last 
few years that large quantities are now being exported to Europe. Arab 
countries, traditionally dependent on Lebanon and Syria, are now reporting 
increasing domestic cultivation attempts. Many countries of Europe, especially 
the southern countries of Spain, Italy, Portugal and Greece, are reporting 
cultivation. India noted that both its legal (in the states of West Bengal, 
Orissa and Madhya Predesh) and illegal (all other states) under a similar 
scheme. In the Near and Middle East, notably Nepal, Pakistan and Afghanistan, 
the people are continuing their traditional production of cannabis for local and 
export use. 
Australia, a country whose huge size (roughly that of the US) and relatively 
sparse population make it virtually ideal for cultivation, reported widespread 
cultivation and seizures of over 70,000 kilos of cannabis, 2,500 kilos of 
hashish, and 850,000 plants uprooted in a two-year period between 1977 and 1978. 
Many people living on Pacific islands such as New Zealand, New Caledonia, Fiji, 
the Cook Islands and elsewhere have discovered that cannabis will grow very well 
in their environment; Jamaica and other islands in the Caribbean are also 
experiencing an increase in cultivation. Recent newspaper reports from that 
country indicate that as many as 1/2 million Jamaican farmers out of a total 
population of 2 million may be producing cannabis to satisfy domestic and export 
demand. The total gross income from the Jamaican cannabis business is estimated 
to exceed $200 million a year3. 
Virtually every country in South America reported at least some cannabis 
cultivations. In addition to increased production in Colombia, whose 1978 crop 
was estimated to be worth between $1.5 and $2 billion, other countries are 
experiencing an increase in cultivation. Over 50,000 acres of cannabis were 
discovered under cultivation in western Venezuela in 1978. In 1976 in Brazil, 
271 kilos of cannabis were reported seized, but the next year increased to 
91,207 kilos, and by 1978, authorities seized over 276,000 kilos. Cultivation 
was also reported in Argentina, Ecuador, Guyana, Surinam and Uruguay. Soviet 
officials go to inordinate lengths to deny that cannabis-use exists in their 
country though Russia is known to be a large cannabis producer, and not just for 
commercial purposes. (Soviet officials reported to the United Nations that they 
seized only 227 grams of cannabis in the entire country4 in 1978; the few 
offender were immediately sent to psychiatric hospitals.) In several Eastern 
European countries the best hashish is knows as "Tashkenti," named for the major 
city in south-central Russia. Tashkent is ethnically dominated by Turkic 
tribesmen and shares the Hindu Kush mountain range with Afghanistan. 
The key to stability in the cannabis market is clearly domestic production, 
which offers many economic and social advantages over continued importation. 
Domestic varieties offer ease of access and supply, and help to diversify the 
overall market by offering new products which compete in quality and price with 
the imported varieties. In addition, they serve to stimulate the local 
concentrating bulk of the profits in the region in which they were produced. 
This is a noticeable reversal of the previous consumer-producer relationship, 
where most of the profits were realized by exporters and middlepersons who 
operated outside the source country. Expanded domestic production would decrease 
the influence of these middlepersons and greatly strengthen the overall market. 
This book was written to make the consumer aware of how easy (and important) it 
is to cultivate cannabis. In a clear and simply style, Mel Frank and Ed 
Rosenthal describe everything you need to know about growing cannabis. By 
employing some of these simple methods you can greatly reduce your dependence on 
foreign products and at the same time gain a greater understanding of a plant 
whose relationship with humanity dates to prehistoric times. 
Be fruitful, and multiply...
  Bob Pisani Coordinator, International Cannabis Alliance for Reform (ICAR) 
  Philadelphia, PA 



Preface
The purpose of this book is to show you how to grow enough marijuana to supply 
all your family's needs. It doesn't matter where you live, or even if you are 
growing your first plant, because all the information needed to become a master 
marijuana farmer in your own home, or in the field, is provided in these pages. 
The world has seen an enormous increase in marijuana use in the past ten years. 
Consequently, many governments have sponsored research in order to understand 
the nature of the plant as well as its psychoactive compounds - substances that 
are being smoked or ingested by more then 400 million people all over the world. 
Before the recent interest, marijuanaphiles had only research papers (mostly on 
hemp varieties) to glean for information about the plants and their cultivation. 
Now there are thousands of papers dealing directly with the plants and their use 
as marijuana. This doesn't mean all is known about marijuana. In fact, much of 
what is discussed deals with unknown aspects of these ancient and mysterious 
plants. The mysteries, however, are beginning to unravel. 
Our information resources include our personal experience with growing and the 
experience and knowledge shared with us by marijuana growers all across the 
country. We also rely on the professional research of many scientists (see the 
Bibliographic Notes). For the experienced growers, we've included the latest 
research on increasing potency, some ideas for improving yield and controlling 
flowering (time of harvest), and also procedures for breeding quality strains 
suited to a particular growing situation. 
Some of the best grass in the world is grown right here in the United States 
(that is our very own stoned opinion of homegrown gratefully sampled from Hawaii 
to Maine). You can do it too - it's not magic, and it's not difficult to do. 
Highly potent plants can be grown indoors, as well as in gardens, fields, and 
the wilds. Indoor growers must create an environment, whereas outdoor gardeners 
work within the environment. Following these two approaches to cultivation, this 
book is divided into separate, parallel parts on indoor and outdoor sections, 
preceded by some background information on marijuana plants, and followed by 
general procedures for breeding, harvesting, etc., that are independent of the 
type of growing site. 
Cultivation is not a complicated process, and we hope we don't make it appear 
difficult. But even if you're a novice when you first sow your seeds, your 
questions on the plants and their cultivation will become more complex as you 
gain experience and insight. We hope we have anticipated your questions with 
solid and clearly stated answers; we intend this book to serve as a guide long 
after your first reading and harvest. 
There are probably as many ways to grow marijuana as there are marijuana 
farmers. We hope to impart an understanding of the plants and their cultivation, 
so that you can adapt the knowledge to fit your particular situation - where you 
live, the land or space available, and the time, energy, and funds at your 
disposal. 
Modest indoor gardens are quite simple to set up and care for. All the materials 
you'll need are available at nurseries, garden shops, and hardware and lighting 
stores, or they may be found around the house or streets. The cost will depend 
on how large and elaborate you make the garden and on whether you buy or 
scavenge your materials. With a little ingenuity, the cost can be negligible. 
It takes about an hour every three or four days to water and tend to a 
medium-sized indoor garden. 
Outdoors, a small patch in your summer garden can supply all your smoking needs 
with little or no expense. Generally, marijuana requires less care than most 
other crops, because of its natural tenacity and ability to compete with 
indigenous weeds. Hardy Cannabis resists mild frost, extreme heat, deluge, and 
drought. In this country, few diseases attack marijuana; once the plants are 
growing, they develop their own natural protection against most insects. 
In some areas of the country, such as parts of the Midwest and East, the plants 
may require no more attention than sowing the seeds in spring and harvesting the 
plants in autumn. But if you're like most growers, you'll find yourself spending 
more and more time in your garden, watching the tiny sprouts emerge, then 
following their development into large, lush, and finally resinous, flowering 
plants. 
Nurturing and watching these beautiful plants as they respond can be a 
humanising experience. Marijuana farmers know their plants as vital living 
organisms. If you already are a plant grower, you may understand. If not, read 
through this book, imagining the various decisions you, as grower, would be 
making to help your plants reach a full and potent maturity. Then make your 
plans and get started. There's just no reason to pay $50 an ounce for superior 
smoke when it grows for free. Free, grass, free yourself. 
This book is the result of the efforts of many people, each of whom contributed 
uniquely to its final form and content. First there are the many growers who 
opened their hearts and gardens to us. Our love and thanks to our friends in 
California (Calistoga, Calavaras, Humbolt, Orange counties, and the Bay Area), 
the Umpqua Valley, Oregon, Eastern Colorado, Central Florida, Eastern 
Massachusetts, Upstate New York, New York City, Atlanta, Hawaii, and Port 
Antonio, Jamaica. We would also like to thank everyone who wrote and shared 
their growing experiences with us. 
Specifically, we would like to acknowledge the contributions of the following: 
Editors; Aiden Kelly, Peter Beren, Ron Lichty, and Sayre Can Young. Preparation 
of the manuscript; Carlene Schnabel, Ron Lichty, Aiden Kelly, Marina La Palma. 
Index by Sayre Van Young. Layout and Design; Bonnie Smetts. Graphics; maps and 
charts by E.N. Lainca; illustration by Oliver Williams; and molecules by Marlyn 
Amann. Special Services; Gorden Brownell, Al Karger, Michael Starks, Peter 
Webster, and special thanks to Sandy Weinstein for help with the photography. 
Also thank you M.T., A.P., and C.T. Special thanks; Sebastian Orfila and John 
Orfali. 
We were fortunate to have had the use of the following libraries: Bronx 
Botanical Gardens, City College of New York, Fitz Hugh Ludlow Memorial Library, 
Harvard Botanical Museum, New York City Public Libraries, University of 
California, Berkeley and San Francisco, University of Mississippi, Oxford. 



Chapter One
History and Taxonomy of Cannabis
1.2 CANNABIS AND ANCIENT HISTORY 
The ancestors of Cannabis originated in Asia, possibly on the more gentle slopes 
of the Himalayas or the Altai Mountains to the north. The exact origin, obscured 
by Stone Age trails the cross the continent, is not known. 
We don't know when Cannabis and humanity first met. Given the growth habit of 
the plant and the curiosity of humanity, such a meeting was inevitable. In the 
plant world, Cannabis is a coloniser. It establishes new territory when running 
water or seed-eating animals carry seed to cleared and fertile soil open to the 
sun. Fertile soil, clear of competing plants, is rare and short-lived in nature, 
and is commonly caused by catastrophe such as flood or earthslide. Natural 
dissemination is slow and the plats tend to grow in thick stands by dropping 
seed about the spread of their branches. 
During the Neolithic era, some 10,000 years ago nomadic groups scavenged, 
hunted, fished, and gathered plants in an unending search for food. The search 
ended when they learned to plant the native grains (grasses) and developed 
agriculture. Agriculture requires a commitment to the land and grants a steady 
food supply which enables people to form permanent settlements. Cannabis and 
Neolithic bands probably came in contact often as the plants invaded the fertile 
clearings - the campsites, roadsides, fields and garbage heaps - that occur 
wherever people live. 
In 1926 the Russian botanist Vavilov summarised the observations of his comrade, 
Sinkaia, on the domestication of hemp by peasants of the Altai Mountains: "1. 
wild hemp; 2. spreading of hemp from wild centers of distribution into populated 
areas (formation of weedy hemp); 3. utilisation of weedy hemp by the population; 
4. cultivation of hemp."24 
The plants which people learn to use help define aspects of their way of life, 
including perceptions of the world, health, and the directions their 
technologies and economies flow. The plants you are about to grow are descended 
from one of the ancient plants that made the transition to civilisation 
possible. 
The earliest cultural evidence of Cannabis comes from the oldest known Neolithic 
culture in China, the Yang-shao, which appeared along the Yellow River valley 
about 6,500 years ago (*Cannabis is known to have been used in the Bylony 
culture of Central Europe (about 7,000 years ago).184). The clothes the people 
wore, the nets they fished and hunted with, and the ropes they used in the 
earliest machines were all made of the long, strong, and durable fibre, hemp. 
This valuable fibre separates from the stem of Cannabis when the stem decays 
(rets). 
In the early classics of the Chou dynasty, written over 3,000 years ago, mention 
is often made of "a prehistoric culture based on fishing and hunting, a culture 
without written language but which kept records by tying knots in ropes. Nets 
were used for fishing and hunting and the weaving of nets eventually developed 
into clothmaking."8 These references may well be to the Yang-shao people. 
As their culture advanced, these prehistoric people replaced their animal skins 
with hemp cloth. At first, hemp cloth was worn only by the more prosperous, but 
when silk became available, hemp clothed the masses. 
People in China relied on Cannabis for many more products than fibre. Cannabis 
seeds were one of the grains of early China along with river barley, millet, and 
soybeans. The seeds were ground into a meal, or roasted whole, or cooked in 
porridge. The ancient tombs of China had sacrificial vessels filled with hemp 
seed and other grains for the afterlife. From prehistoric times there is a 
continuos record of the importance of hemp seed for food until the first to 
second century BC when the seed had been replaced by more palatable cereal 
grains.7 (an interesting note from the Tung-kuan archives (28 AD) records that 
after a war-caused famine the people subsisted on "wild" Cannabis and soybean.8) 

The effects of Cannabis' resinous leaves and flowers did not go unnoticed. The 
Oen-ts-ao Ching, the oldest pharmacopoeia known, states that the fruits 
(flowering tops) of hemp, "if taken in excess will produce hallucinations" 
(literally "seeing devils"). The ancient medical work also says, "If taken over 
a long term, it makes one communicate with spirits and lightens one's body."9 
Marijuana, with a powerful effect on the psyche, must have been considered a 
magical herb at a time when medical concepts were just being formed. The P[e 
hat]n-ts'ao Ching, speaking for the legendary Emperor Sh[e hat]n-nung of about 
2000 BC, prescribes marijuana preparations for "malaria, beriberi, constipation, 
rheumatic pains, absent-mindedness, and female disorders."15 Even the Cannabis 
root found its place in early medicine. Ground to form a paste, it was applied 
to relive the pain of broken bones and surgery. 
New uses were discovered for Cannabis as Chinese civilisation progressed and 
developed new technologies. The ancient Chinese leaned to mill, heat, and then 
wedge-press Cannabis seeds to extract the valuable oil, a technique still used 
in the western world in the twentieth century. Pressed seeds yielded almost 20 
percent oil by weight. Cannabis oil, much like linseed oil, could be used for 
cooking, to fuel lamps, for lubrication, and as the base in paint, varnish, and 
soap making. After oil extraction, the residue or "hemp cake" still contained 
about 10 percent oil and 30 percent protein, a nutritious feed for domesticated 
animals. 
Another advancement came with the Chinese invention of paper. Hemp fibres 
recycled from old rags and fish nets made a paper so durable that some was 
recently found in graves in the Shense province that predates 100 BC (9) Hemp 
paper is known for its longevity and resistance to tearing, and is presently 
used for paper money (Canada) and for fine Bibles. 
The ancient Chinese learned to use virtually every part of the Cannabis plant: 
the root for medicine,; the stem for textiles, rope and paper making; the leaves 
and flowers for intoxication and medicine; and the seeds for food and oil. Some 
of the products fell into disuse only to be rediscovered by other people at 
other times. 
While the Chinese were building their hemp culture, the cotton cultures of India 
and the linen (flax) cultures of the Mediterranean began to learn of Cannabis 
through expanding trade and from wandering tribes of Aryans, Mongols, and 
Scythians who had bordered China since Neolithic times. 
The Aryans (Indo-Persians) brought Cannabis culture to India nearly 4,000 years 
ago. They worshipped the spirits of plants and animals, and marijuana played an 
active role in their rituals. In China, with the strong influence of philosophic 
and moralistic religions, use of marijuana all but disappeared. But in India, 
the Aryan religion grew through oral tradition, until it was recorded in the 
four Vedas, compiled between 1400 and 1000 BC. In that tradition, unlike the 
Chinese, marijuana was sacred, and the bhangas spirit was appealed to "for 
freedom of distress" and as a "reliever of anxiety" (from the Atharva Veda).1 A 
gift from the gods, according to Indian mythology, the magical Cannabis "lowered 
fevers, fostered sleep, relieved dysentery, and cured sundry other ills; it also 
stimulated the appetite, prolonged life, quickened the mind, and improved the 
judgement."15 
The Scythians brought Cannabis to Europe via a northern route where remnants of 
their campsites, from the Altai Mountains to Germany, date back 2,800 years. 
Seafaring Europe never smoked marijuana extensively, but hemp fibre became a 
major crop in the history of almost every European country. Pollen analysis 
dates the cultivation of Cannabis to 400 BC in Norway, although it is believed 
the plant was cultivated in the British Isles several centuries earlier.2 The 
Greeks and Romans used hemp for rope and sail but imported the fibre from Sicily 
and Gaul. And it has been said the "Caesar invaded Gaul in order to tie up the 
Roman Empire," an allusion to the Romans' need for hemp. 
Marijuana, from its stronghold in India, moved westward through Persia, Assyria 
and Arabs by 500 AD. With the rising power if Islam, marijuana flourished in a 
popular form as hashish. In 1378, the Emir Soudon Sheikhouni tried to end the 
use of Indian hashish by destroying all such plants, and imprisoning all users 
(first removing their teeth for good measure). Yet in a few years marijuana 
consumption had increased.1 
Islam had a strong influence on the use of marijuana in Africa. However, its use 
is so ingrained in some ancient cultures of the Zambezi Valley that is 
appearance clearly predated Islam. Tribes from the Congo, East Africa, Lake 
Victoria, and South Africa smoke marijuana in ritual and leisure. The ancient 
Riamba cult is still practiced in the Congo. According to the Riamba beliefs, 
marijuana is a god, protector from physical and spiritual harm. Throughout 
Africa treaties and business transactions are sealed with a puff of smoke from a 
yard-long pipe.(15) 
With increased travel and trade, Cannabis seed was brought to all parts of the 
known world by ships and caravans rigged with the fibre of its kind. And when 
the first settlers came to the Americas, they brought the seed with them. 
1.3 CANNABIS AND AMERICAN HISTORY
Like their European forbears, Americans cultivated Cannabis primarily for hemp 
fibre. Hemp seed was planted in Chile in 1545,(64) Canada in 1606, Virginia in 
1611, and in the Puritan settlements in Massachusetts in the 1630s(15). 
Hemp-fibre production was especially important to the embryonic colonies for 
homespun cloth and for ship rigging. In 1637, the General Court at Hartford 
ordered that "every family within this plantation shall procure and plant this 
present year one spoonful of English hemp seed in some soyle."(12) 
Hemp growing was encouraged by the British parliament to meet the need for fibre 
to rig the British fleets. Partly to dissuade the colonists from growing only 
tobacco, bounties were paid for hemp and manuals on hemp cultivation were 
distributed. In 1762, that state of Virginia rewarded hemp growers and "imposed 
penalties upon those that did not produce it."(2) 
The hemp industry started in Kentucky in 1775 and in Missouri some 50 years 
later. By 1860, hemp production in Kentucky alone exceeded 40,000 tons and the 
industry was second only to cotton in the South. The Civil War disrupted 
production and the industry never recovered, despite several attempts by the 
United States Department of Agriculture to stimulate cultivation by importing 
Chinese and Italian hemp seed to Illinois, Nebraska, and California. Competition 
from imported jute and "hemp" (Musa textiles) kept domestic production under 
10,000 tons per year. In the early 1900s, a last effort by the USDA failed to 
offset the economic difficulties of a labour shortage and the lack of 
development of modern machinery for the hemp industry (64). However, it was 
legal force that would bring an end to US hemp production. 
For thousands of years marijuana had been valued and respected for its medicinal 
and euphoric properties. The Encyclopaedia Brittanica of 1894 estimated that 300 
million people, mostly from Eastern countries, were regular marijuana users. 
Millions more in both the East and the West received prescription marijuana for 
such wide-ranging ills as hydrophobia and tetanus. 
By the turn of the century, many doctors had dropped marijuana from the 
pharmacopoeias: drugs such as aspirin, though less safe (marijuana has never 
kill anyone), were more convenient, more predictable, and more specific to the 
condition being treated. Pill-popping would become an American institution. 
Marijuana was not a legal issue in the United States until the turn of the 
twentieth century. Few Americans smoked marijuana, and those that did were 
mostly minority groups. According to author Michael Aldrich, (1) "The 
illegalisation of Cannabis came about because of who was using it" - Mexican 
labourers, southern blacks, and the newly subjugated Filipinos. 
In states where there were large non-white populations, racist politicians 
created the myths that marijuana caused insanity, lust, violence and crime. One 
joint and you were addicted, and marijuana led the way to the use of "equivalent 
drugs" - cocaine, opium and heroin. These myths were promoted by ignorant 
politicians and journalists, who had neither experience nor knowledge of 
Cannabis, and grew into an anti-marijuana hysteria by the next generation. 
For example, the first states to pass restriction on marijuana use were in the 
Southwest, where there were large populations of migrant workers from Mexico. 
One of the first states to act was California, which, "with its huge Chicano 
population and opium smoking Chinatowns, labelled marijuana 'poison' in 1907, 
prohibited its possession unless prescribed by a physician in 1915, and included 
it among hard narcotics, morphine and cocaine in 1929." (1) 
In marijuana, the mainstream society found a defenceless scapegoat to cover the 
ills of poverty, racism, and cultural prejudice. San Franciscans "were 
frightened by the 'large influx of Hindoos ... demanding Cannabis indica' who 
were initiating 'the whites into their habit.'" (11) Editorialists heightened 
public fears with nightmarish headlines of the "marijuana menace" and "killer 
weed," and fear of Cannabis gradually spread through the West. By 1929, 16 
western states had passed punitive restrictions governing marijuana use. 
{Figure 5.  (Sample -- Warning card to be placed in R. R. Trains, Buses,
Street Cars, etc.)
Beware! Young and Old - People in All Walks of Life!
This {joint} may be handed you by the friendly stranger.
It contains the Killer Drug "Marihuana" -- a powerful narcotic
in which lurks Murder!  Insanity!  Death!
WARNING!
Dope peddlers are shrewd!  They may put some of this drug in the {teapot}
or in the {cocktail} or in the tobacco cigarette.
WRITE FOR DETAILED INFORMATION, ENCLOSING 12 CENTS IN
POSTAGE -- MAILING COST
Address: THE INTER-STATE NARCOTIC ASSOCIATION
(Incorporated not for profit)
52W Jackson Blvd.   Chicago, Illinois, U.S.A.

{'This may be handed you by the ...' is a mistake on the poster}}
Marijuana was not singled out by anti-drug campaigners. During this time, 
Congress not only banned "hard" narcotics, but also had prohibited alcohol and 
considered the prohibition of medical pain killers and even caffeine. 
The Federal Bureau of Narcotics was established in 1930 with Harry Anslinger as 
its first commissioner. During the first few years of operation, the bureau 
minimised the marijuana problem, limited mostly to the Southwest and certain 
ghettos in the big cities of the East. However, the bureau was besieged with 
pleas from local police and sheriffs to help with marijuana problems. The FBN 
continued to resist this pressure, because Commissioner Anslinger had serious 
doubts as to whether federal law restricting marijuana use could be sustained as 
constitutional. Further, FBN reports indicate that the bureau did not believe 
that the marijuana problem was as great as its public reputation. Control of the 
drug would also prove extremely difficult, for as Anslinger pointed out, the 
plant grew "like dandelions." (11) 
The joblessness and misery of the depression added impetus to the anti-marijuana 
campaign. This came about indirectly, by way of focusing public sentiment 
against migrant and minority workers who were blamed for taking "American" jobs. 
Much of this sentiment grew out of cultural and racial prejudice and was 
supported by groups such as Key Men of America and the American Coalition. The 
goal of these groups was to "Keep America American." 
However, by 1935 almost every state had restricted marijuana use, and local 
police and influential politicians had managed to pressure the FBN to seek a 
federal marijuana law. The constitutional question could be circumvented by 
cleverly tying restrictions to a transfer tax, effectively giving the federal 
government legal control of marijuana. 
With this new tack, the FBN prepared for congressional hearings on the Marijuana 
Tax Act so that passage of the bill would be assured. Anslinger and politicians 
seeking to gain from this highly emotional issue railroaded the Marijuana Tax 
Act through the 1937 Congress. Anslinger made sure that "the only information 
that they (the congressmen) has was what we would give them at the hearings." 
(11) No users were allowed to testify in pot's defence, and doctors and 
scientists were ridiculed for raising contrary views (16). The new federal law 
made both raising and use of the plant illegal without the purchase of a 
hard-to-acquire federal stamp. The FBN immediately intensified the propaganda 
campaign against marijuana and for the next generation, the propaganda continued 
unchallenged. 
The marijuana hysteria also ended any hopes for a recovery of the hemp industry. 
What had been needed was a machine that would solve the age-old problem of 
separating the fibre from the plant stem, an effort which required considerable 
skilled labour. The machine that could have revolutionised hemp production was 
introduced to the American public in the February 1938 edition of Popular 
Mechanics. But the Marijuana Tax Act has been passed four months earlier, and 
the official attitude toward all Cannabis is best illustrated by this quote from 
Harry J. Anslinger, commissioner of the Federal Bureau of Narcotics: "Now this 
(hemp) is the finest fibre known to man-kind, my God, if you ever have a shirt 
made of it, your grandchildren would never wear it out. You take Polish 
families. We'd go in and start to tear it up and the man came out with his 
shotgun yelling, 'These are my clothes for next winter!'" (2) 
During the war years, after the Japanese had cut off America's supply of manila 
hemp, worried officials supplied hemp seed and growing information to Midwestern 
farmers. In Minnesota, Iowa, Illinois, and Wisconsin, hemp farmers showed their 
wartime spirit by producing over 63,000 tons of hemp fibre in 1943. 
Unlike many of our ancient domesticated plants, Cannabis never lost its 
colonising tendencies or ability to survive without human help. Cannabis readily 
"escapes" cultivated fields and may flourish long after its cultivation is 
abandoned. However, Cannabis always keeps in contact by flourishing in our waste 
areas - our vacant fields and lots, along roads and drainage ditches, and in our 
rubbish and garbage heaps. Perhaps it awaits discovery by future generations. 
The cycle has been repeated many times. 
States that once supported hemp industry are now dotted with stands of escaped 
weedy hemp. Weedy hemp grows across the country, except in the Southwest and 
parts of the Southeast. Distribution is centered heavily in the Midwest. Most of 
these plants are descended from Chinese and European hemp strains that were bred 
in Kentucky and the grown in Midwestern stated during World War II. But some 
weed patches, such as in Kentucky and Missouri, go back perhaps to revolutionary 
times. 
The Anslinger crusades that continued through the sixties are a fine example of 
government propaganda and control of individual lives and beliefs. We still feel 
the ramifications in our present laws and in the fear-response to marijuana 
harboured by many people who grew up with Anslingian concepts. Poor Cannabis, 
portrayed as a dangerous narcotic that would bring purgatory upon anyone who 
took a toke - violence, addiction, lust, insanity - you name it, and marijuana 
caused it. All it ever did to us was get us stoned ... things slowed down a bit 
... enough to stop and look around. 
{Figure 6.  A weedy hemp stand in Nebraska.}
Hopefully, we are living in the last years of the era of illegal marijuana and 
the persecution of this plant. Cannabis is truly wondrous, having served human 
needs for, perhaps, 10,000 years. It deserves renewed attention not only for its 
chemical properties, but also as an ecologically sensible alternative for 
synthetic fibres in general and especially wood-pulp paper. May Cannabis be 
vindicated. 
1.4 Cannabis: Species or Varieties
The 10,000-year co-evolution of Cannabis and humanity has had a profound impact 
on both plant and humans. Cannabis has affected our cultural evolution; we have 
affected the plant's biological evolution. 
From small populations of ancient progenitors, hundreds of varieties or strains 
of Cannabis have evolved. These variations can be traced to human acts, both 
planned and accidental. 
Ancient farmers, knowing that like begets like, selected Cannabis for certain 
characteristics to better suit their needs. With the need for fibre, seeds from 
plants with longer stems and better fibres were cultivated. Gradually, their 
descendants became taller, straight-stemmed, and had a minimum of branches. Some 
farmers were interested in seed and oil. They developed large-seeded, bushy 
plants that could bear an abundance of seeds. Marijuana farmers interested in 
potency selected plants that flowered profusely with heavy resin and strong 
psychoactive properties. 
The subsequent variations in Cannabis are striking. In Italy, where hemp fibre 
supports a major textile and paper industry, some fibre varieties grow 35 feet 
in a single season. Other Italian varieties may reach only five or six feet in 
height, but have slender, straight stems that yield a fibre of very fine 
quality. In Southeast Asia, some marijuana plants grow only four feet or less, 
yet these are densely foliated and heavy with resin. Other varieties of 
marijuana grow 15 to 20 feet in a season and yield over a pound of grass per 
plant. 
Breeding plants is a conscious act. The plant's evolution, however, has also 
been affected by its introduction to lands and climates different from its 
original home. Whether plants are cultivated or weeds, they must adapt to their 
environment. Each new country and growing situation presented Cannabis with new 
circumstances and problems for survival. The plants have been so successful at 
adapting and harmonising with new environments that they are now considered the 
most widely distributed of cultivated plants. (45) 
In French, Cannabis is sometimes called "Le Chanvre troumper" or "tricky hemp," 
a name coined to described its highly adaptable nature. The word adaptable 
actually has two meanings. The first refers to how a population of plants (the 
generic pool) adjusts to the local environment over a period of generations. 
(The population is, in practice, each batch of seeds you heave, or each existing 
stand or field.) For instance, a garden with some plants that flower late in the 
season will not have time to seed in the north. The next year's crop will come 
only from any early seeding plants. Most of them will be like their parents and 
will set seed early. (See section 18.) 
Adaptable is a term that also applies to the individual living plant (phenotype) 
and, in practical terms, means that Cannabis is tenacious and hardy -- a 
survivor among plants. It thrives under a variety of environmental conditions, 
whether at 10,000 feet in the Himalayas, the tropical valleys of Colombia, or 
the cool and rainy New England coast. 
Through breading and natural selection, Cannabis has evolved in many direction. 
Botanically and historically, the genus is so diverse that many growers are 
confused by the mythology, exotic names, and seeming contradictions that 
surround the plants. Many inconsistencies are explained by understanding how 
variable Cannabis is. There are hundreds of wild, weedy, and cultivated 
varieties. Cultivated varieties may be useful for only hemp, oil, or marijuana. 
"Strains," "varieties," "cultivars," "chemovars," or "ecotypes" differ widely in 
almost every apparent characteristic. Varieties range from two to 35 feet tall; 
branching patterns run from dense to quite loose, long (five or six feet) or 
short (a few inches). Various branching patterns form the plant into shapes 
ranging from cylindrical, to conical, to ovoid, to very sparse and gangly. The 
shape and colour of leaves and stems, seeds, and flowering clusters are all 
variable characteristics that differ among varieties. Life cycles may be as 
short as three months, or the plants may hang on to life for several years. Most 
importantly, different varieties provide great variations in the quality and 
quantity of resin they produce, and hance in their psychoactive properties and 
value as marijuana. 
The taxonomy (ordering and naming) of Cannabis has never been adequately carried 
out. Early research placed the genus Cannabis within the Families of either the 
Moraceae (mulberry) or the Urticaceae (nettle). Now there is general agreement 
that the plant belongs in a separate family, the Cannabaceae, along with one 
other genus, Humulus, the hops plant. (See section on Grafting in section 18.) 
A modern Scheme for the phylogeny of Cannabis would be: 
	Subdivision	Angiospermae (flowering plants)
	Class	Dicotyledoneae (dicots)
	Order	Uriticales (nettle order)
	Family	Cannabaceae (hemp family)
	Genus	Cannabis (hemp plant)
Below the genus level, there is no general agreement on how many species should 
be recognised within Cannabis. The Cannabis lineage has not been possible to 
trace after thousands of years of human intervention. 
Most research refers to Cannabis as a single species - Cannabis sativa L. (The 
word Cannabis comes from ancient vernacular names for hemp, such as the Greek 
Kannabis; sativa means "cultivated" in Latin; L. stands for Linnaeus, the 
botanical author of the name.) But some botanists who are studying Cannabis 
believe there are more than one species within the genus. 
Richard Schultes, for example, describes three separate species (see Box A) 
based on variations in characteristics believed not to be selected for by humans 
(natural variations) such as seed colour and abscission layer (scar tissue on 
the seed which indicates how it was attached to the stalk). 
  BOX A
  Schultes' Key as it appears in Harvard Botanical
  Museum Leaflets (45)
  Cannabis Sativa
  1. Plants usually tall (five to 18 feet), laxly branched; akenes ((Akene (or 
  Achene) is the botanical name for the fruit of Cannabis. In Cannabis, the 
  fruit is essentially the seed.)) smooth, usually lacking marbled pattern on 
  outer coat, firmly attached to stalk and without definite articulation. 
  Cannabis Indica
  1A. Plant usually small (four feet or less), not laxly branched; akenes 
  usually strongly marbled on outer coat, with a definite abscission layer, 
  dropping off at maturity. 
  2. Plants very densely branched, more or less conical, usually four feet tall 
  or less; abscission layer a simple articulation at base of akene. 
  Cannabis ruderalis ((Limited to parts of Asia.))
  2A. Plants not branched or very sparsely so, usually one to two feet at 
  maturity. Abscission layer forms a fleshly carbuncle-like growth at base of 
  akene. 
Ideally, the classification of living things follows a natural order, reflecting 
relationships as they occur in nature. Species are groups of organisms that are 
evolving as distinct units. Biologically, the evolutionary unit is the 
population, a population being a group of freely inbreeding organisms. Living 
things don't always fit neatly into scientific categories. And the meaning of 
species changes with our understanding of life and the evolutionary processes. 
Often, the definition of species will depend on the particular being studied. 
A traditional way of defining separate species is that off-spring that result 
cannot reproduce successfully. As far as is known, all Cannabis plants can cross 
freely, resulting in fully fertile hybrids (107). But growth habit and actual 
gene exchange are important considerations in plant taxonomy. If different 
populations never come in contact, then there is no pressure for them to develop 
biological processes to prevent them mixing. Cannabis is pollinated by the wind. 
Although wind may carry pollen grains hundreds of miles, almost all pollen falls 
within a few feet of the parent plant. The chance of a pollen grain fertilising 
a tiny female flower more than 100 yards away is extremely small (201). Hence, 
separate stands or fields of Cannabis (populations) are quite naturally 
isolated. For Cannabis, the fact that populations are isolated by distance is 
not sufficient grounds for labelling them separate species, nor is successful 
hybridisation reason enough to group all populations as one species. 
The species question and Cannabis mythology are complicated by the plant's 
ability to rapidly change form and growth habits. These changes can be measured 
in years and decades, rather than centuries or millennia. 
The fact that a pollen grain does occasionally fertilise a distant flowers leads 
to a process called introgression. Introgression means that new genes (new 
variations and possible variations) are incorporated into the population via the 
foreign pollen. This crossing between populations leads to an increase in 
variation within the population, but a decrease in the differences between the 
populations. Although introgression confuses the species question, it also adds 
to the plant's adaptable nature by providing a resource for adaptive variations. 
In other words, Cannabis has been around. The plants have a rich and varied 
history of experience, which is reflected in their variety and adaptive nature. 
If breeding barriers do not exist, species are often delimited by natural 
differences in morphology (structure or appearance). The natural variations on 
which Schultes' key is based are actually affected by contact with farmers. For 
instance, seeds which drop freely from the plant are less likely to be collected 
and sown by the farmer, so that cultivated Cannabis may eventually develop a 
different type of abscission layer than when wild or weedy. 
Seed colour and pattern are affected naturally by the need for camouflage. Under 
cultivation this natural selection pressure would not be the same. Many farmers 
select seeds by colour, believing the darkest are the best developed. In other 
words, there are serious problems with this limited approach to categorising 
species in Cannabis. This does not go unrecognised by Dr. Schultes, and the key 
represents a starting point. However, species should represent distinct groups 
within a genus, and populations with intermediate characteristics should be the 
exception. When you grow marijuana, you'll find that most varieties do not fit 
into any of these categories, but lie somewhere between. The majority of the 
marijuana from the Western Hemisphere would follow this description: plants tall 
(eight to 18 feet); well-branched; akenes usually strongly marbled; base of the 
seed sometimes slightly articulated. 
Other characteristics, such as variations on wood anatomy (17) and leaf form 
(28), have been suggested for delimiting Cannabis species. However, wood 
anatomy, like stem anatomy, can be seriously affected by selection for hemp in 
particular, but also by selection for marijuana and seed. Wood anatomy also 
depends on the portion of the stem examined and on the arrangement of leaves 
(phyllotaxy), which, in turn, is influenced by light levels, photoperiod, and 
the physiological development of the plant. 
Most Cannabis plants have compound leaves with seven to nine blades or leaflets 
per leaf. Occasionally, varieties are seen where all the leaves have only one to 
three blades (monophyllous). Such plants sometimes arise from varieties with 
compound leaves. The factor is genetic, but carries little weight for the 
separation of species. 
Human selection for particular traits can powerfully alter plants. Sex 
vegetables - cabbage, cauliflower, brussel sprouts, broccoli, kale, and kohlrabi 
- are all descended from a single wild species of mustard herb, Brassica 
oleracea (216). Human preference for particular parts of the plant led to their 
development. All six are still considered one species. 
Any classification of species in Cannabis, based solely on morphological 
grounds, will prove difficult to justify with our present knowledge of the 
plant. At this time it seems that all Cannabis should be considered one species, 
Cannabis sativa L. 
{Figure 7.  Common marijuana leaf with seven blades (Colombian)}
{Figure 8.  Four leaf types from Colombian marijuana varieties}
{Figure 9.  Leaf blades from Figure 8.}
The debate on whether there is more than one species has been intense, for the 
issue has legal implications. Many laws specifically prohibit only Cannabis 
sativa. Presumably other species would not be prohibited. However, in the United 
States, this argument was recently dismissed when tested in a California court. 
The court upheld the argument that the law's intent is clear, although it may be 
questionable botanically: under law all Cannabis are regarded alike. 
Luckily, the controversy over the number of species is of no more than academic 
interest to the marijuana grower. The most important characteristic to 
enthusiasts is the quality or potency of the grass they'll grow. 
Potency is mostly a factor of heredity. The quality of the grass you grow 
depends on how good its parents were, so choose seeds from the grass you like 
best. 
The environment has an impact, too, but it can only work on what is contained in 
the seed. A potent harvest depends on an environment which encourages the seed 
to develop to a full and potent maturity. The way to begin is to find the most 
potent grass you can; then you will have taken the first step. 



  CHAPTER 2
  CANNABINOIDS: THE ACTIVE INGREDIENTS OF MARIJUANA
Cannabis is unique in many ways. Of all plants, it is the only genus known to 
produce chemical substances known as cannabinoids. The cannabinoids are the 
psychoactive ingredients of marijuana; they are what get you high. By 1974, 37 
naturally occurring cannabinoids had been discovered 115,118. Most of the 
cannabinoids appear in very small amounts (less than .01 percent of total 
cannabinoids) and are not considered psychoactive, or else not important to the 
high. Many are simply homologues or analogues (similar structure or function) to 
the few major cannabinoids which are listed. 
  1. (-)-{triangle}9-trans-tetrahydrocannabinol ((There are several numbering 
  systems used for cannabinoids. The system in this book is most common in 
  American publications and is based on formal chemical rules for numbering 
  pyran compounds. Another common system is used more by Europeans and is based 
  on a monoterpenoid system which is more useful considering the biogenesis of 
  the compound.)) This (delta-9 THC) is the main psychotomimetic (mindbending) 
  ingredient of marijuana. Estimates state that 70 to 100 percent (121) of the 
  marijuana high results from the delta-9 THC present. It occurs in almost all 
  Cannabis in concentration that vary from traces to about 95 percent of all the 
  cannabinoids in the sample. In very potent varieties, carefully prepared 
  marijuana can have up to 12 percent delta-9 THC by dry weight of the sample 
  (seeds and stems removed from flowering buds). (("Buds" of commercial 
  marijuana is the popular name given to masses of female flowers that form 
  distinct clusters.)) 
  Delta-8 THC - This substance is reported in low concentration, less than one 
  percent of the delta-9 THC present. Its activity is slightly less than that of 
  delta-9 THC. It may be an artefact of the extraction/analysis process. Here we 
  refer to delta-9 THC and delta-8 THC as THC. 
  2. Cannabidiol - CBD also occurs in almost all varieties. Concentration range 
  from nil (119,138), to about 95 percent of the total cannabinoids present. THC 
  and CBD are the two most abundant naturally occurring cannabinoids. CBD is not 
  psychotomimetic in the pure form (192), although it does have sedative, 
  analgesic, and antibiotic properties. In order for CBD to affect the high, THC 
  must be present in quantities ordinarily psychoactive. CBD can contribute to 
  the high by interacting with THC to potentiate (enhance) or antagonise 
  (interfere or lessen) certain qualities of the high. CBD appears to potentiate 
  the depressant effects of THC and antagonise is excitatory effects (186). CBD 
  also delays the onset of the high (183) but can make it last considerably 
  longer (as much as twice as long). (The grass takes a while to come on but 
  keeps coming on.) Opinions are conflicting as to whether it increases or 
  decreases the intensity of the high, "intensity" and high" being difficult to 
  define. Terms such as knock-out or sleepy, dreamlike, or melancholic are often 
  used to describe the high from grass with sizeable proportions of CBD and THC. 
  When only small amounts of THC are present with high proportions of CBD, the 
  high is more of a buzz, and the mind feels dull and the body de-energised. 
  {See Figure 11 to 16 for chemical structure in monochrome bitmap format.} 
  3. Cannabinol - CBN is not produced by the plant per se. It is the degradation 
  (oxidative) product of THC. Fresh samples of marijuana contain very little CBN 
  but curing, poor storage, or processing such as when making hashish, can cause 
  much of the THC to be oxidised to CBN. Pure forms of CBN have at most 10 
  percent of the psychoactivity of THC (192). Like CBD, it is suspected of 
  potentiating certain aspects of the high, although so far these affects appear 
  to be slight (183,185). CBN seems to potentiate THC's disorienting qualities. 
  One may feel more dizzy or drugged or generally untogether but not necessarily 
  higher. In fact, with a high proportion of CBN, the high may start well but 
  feels as if it never quite reaches its peak, and when coming down one feels 
  tired or sleepy. High CBN in homegrown grass is not desirable since it 
  represents a loss of 90 percent of the psychoactivity of its precursor THC. 
  4. Tetrahydrocannabivarin - THCV is the propyl homologue of THC. In the 
  aromatic ring the usual five-carbon pentyl is replaced by a short three-carbon 
  propyl chain. The propyl cannabinoids have so far been found in some varieties 
  originating from Southeast and Central Asia and parts of Africa. What are 
  considered some very potent marijuana varieties contain propyl cannabinoids. 
  In one study, THCV made up to 48.23 percent (Afghanistan strain) and 53.69 
  percent (South Africa) of the cannabinoids found (136). We've seen no reports 
  on its activity in humans. From animal studies it appears to be much faster in 
  onset and quicker to dissipate than THC (181). It may be the constituent of 
  one- or two-toke grass, but its activity appears to be somewhat less than that 
  of THC. 
  The propyl cannabinoids are a series corresponding to the usual pentyl 
  cannabinoids. The counterpart of CBD is CBDV; and of CBN, CBV. There are no 
  reports on their activity and for now we can only speculate that they are 
  similar to CBD and CBN. Unless noted otherwise, in this book THC refers 
  collectively to delta-9 THC, delta-8 THC, and THCV. 
  5. Cannabichromene - CBC is another major cannabinoid, although it is found in 
  smaller concentrations than CBD and THC. It was previously believed that is 
  was a minor constituent, but more exacting analysis showed that the compound 
  often reported as CBD may actually be CBC (119,137). However, relative to THC 
  and CBD, its concentration in the plants is low, probably not exceeding 20 
  percent of total cannabinoids. CBC is believed not to be psychotomimetic in 
  humans (121); however, its presence in plants is purportedly very potent has 
  led to the suspicion that it may be interacting with THC to enhance the high 
  (137). Cannabicyclol (CBL) is a degradative product like CBN and CBV (123). 
  During extraction, light converts CBC to CBL. There are no reports on its 
  activity in humans, and it is found in small amounts, if at all, in fresh 
  plant material. 
   
  2.2 Cannabinoids and the High
The marijuana high is a complex experience. It involves a wide range of 
psychical, physical, and emotional responses. The high is a subjective 
experience based in the individual - one's personality, mood, disposition, and 
experience with the drug. Given the person, the intensity of the high depends 
primarily on the amount of THC present in the marijuana. Delta-9 THC is the main 
ingredient of marijuana and must be present in sufficient quantities for a good 
marijuana high. People who smoke grass that has very little cannabinoids other 
then delta-9 THC usually report that the high is very intense. Most people will 
get high from a joint having delta-9 THC of .5 percent concentration to 
material. Grass having a THC concentration of three percent would be considered 
excellent quality by anyone's standards. In this book, for brevity, we use 
potency to mean the sum effects of the cannabinoids and the overall high 
induced. 
Marijuana (plant material) is sometimes rated more potent that the content of 
delta-9 THC alone would suggest. It also elicits qualitatively different highs. 
The reasons for this have not been sorted out. Few clinical studies with known 
combinations of several cannabinoids have been undertaken with human subjects. 
This field is still in its infancy. So far, different highs and possibly higher 
potency seem to be due to the interaction of delta-9 THC and other cannabinoids 
(THCV,CBD,CBN, and possibly CBC). Except for THCV, in the pure form, these other 
cannabinoids do not have much psychoactivity. 
Another possibility for higher potency is that homologues of delta-9 THC with 
longer side chains at C-3 (and higher activity) might be found in certain 
marijuana varieties. Compounds with longer side chains have been mode in 
laboratories and their activity is sometimes much higher, with estimates over 
500 times that of natural delta-9 THC (55,113,191). Compounds besides THCV with 
shorter chains (methyl (139) and butyl (118)) in this position have been found 
in small amounts in some marijuana samples, indicating that variations do exist. 
However, this is not a very likely explanation. More likely, THCV is more 
prevalent in marijuana than supposed and probably had additive or synergistic 
effects with delta-9 THC. 
The possibility that there are non-cannabinoids that are psychoactive or 
interacting with the cannabinoids has not been investigated in detail. 
Non-cannabinoids with biological activity have been isolated from the plants, 
but only in very small quantities (181). None are known to be psychotomimetic. 
However, they may contribute to the overall experience in non-mental ways, such 
as the stimulation of the appetite. 
Different blends of cannabinoids account for high of different qualities. The 
intensity of the high depends primarily on the amount of delta-9 THC present and 
on the method of ingestion. A complex drug such as marijuana affects the mind 
and body in many ways. Sorting out what accounts for what response can become 
quite complex. The methodology to isolate and test the different cannabinoids 
now exists. The National Institute of Mental Health (NIMH) is funding research 
on the pharmacology of marijuana. However, such research is paltry, considering 
that over 30 million people in the United States use the crude drug. Much more 
research is needed before definite understanding of the cannabinoids and the 
high is attained. 
When the legal restriction are removed, marijuana will probably be sold by 
particular blends of cannabinoids and standard amounts of delta-9 THC. Synthetic 
marijuana will probably be made with homologues of delta-9 THC that have much 
higher activity than the natural form. For now, without access to a lab, you 
must be satisfied with your own smoking evaluation (for research purposes only), 
ultimately the most important criterion any way. 
2.3 Resin and Resin Glands
Many people consider potency and resin concentration synonymous. People hear of 
plants oozing or gushing with copious resin, and the image is of resin flowing 
in the plant like the latex of a rubber tree or the sap of a maple tree. But 
these visions are just pipe dreams. 
It is quite possible to have a resinous plant with little potency or a plant 
with little apparent resin which is very potent. Potency depends primarily on 
the concentration of THC in the plant material. Many more substances besides the 
cannabinoids make up the crude resin of Cannabis. Preparations such as ghanja or 
hashish are roughly about one-third by weight non-psychoactive water-soluble 
substances and cellular debris. Another third is non-psychoactive resins such as 
phenoloic and terpenoid polymers, glycerides, and triterpenes. Only one-fourth 
to one-third is the cannabinoids. In many Cannabis plants, THC may be only a 
very small percentage of the total cannabinoids. ((These figures are very 
approximate. Actual percentages depend on sample material, processing, and 
extraction procedures. See Table 8 and 9 for percentages of THC in hashish.)) 
The remainder (5 to 10 percent) of the resin will be essential oils, sterols, 
fatty acids, and various hydrocarbons common to plants. 
Table 8 - Seized Hashish (a) 

                         Range of Percentage of
COUNTRY IN WHICH SEIZED  THC         CBD
Greece                   1 - 15.8    1.4 - 11.1
Nepal                    1.5 - 10.9  8.8 - 15.1
Afghanistan              1.7 - 15    1.8 - 10.3
Pakistan                 2.3 - 8.7   6.8(b)

a Figures compiled from many sources.
b Only one figure reported


Table 9 - Relative Percentages of Major Cannabinoids from Hashish and Resin
          Preparations.
                       Average Percentages of
COUNTRY                THC      CBD      CBN
Afghanistan            52       36       12
Burma                  15.7     16.3     68
Jamaica                77.5      9.1     13.4
Lebanon                32.2     62.5      5.3
Morocco                55       34.2     10.8
Nigeria                53.7      9.3     37
Pakistan               35.7     48.3     16.1
South Africa           75.6      8.4       16

a Each row sums to 100%
_TABLE 9
The cannabinoids basically do not flow in the plant, nor are they the plant's 
sap. About 80 to 90 percent of the cannabinoids are synthesised ad stored in 
microscopic resin glands that appear on the outer surfaces of all plant parts 
except the root and seed. the arrangement and number (concentration) of resin 
glands vary somewhat with the particular strain examined. Marijuana varieties 
generally have more resin glands, and they are larger then resin glands on 
non-drug varieties. 
Although resin glands are structurally diverse, they are of three basic types. 
The bulbous type is the smallest (15-30 um ((um is the symbol for a micrometer 
(or micron), equal to 1/1,000,000 of a meter, or approximately 1/25,000 of an 
inch.)) or about .0006 to .0012 inches). From one to four cells make up the 
"foot" and "stalk," and one to four cells make up the "head" of the gland (25). 
Head cells secrete a resin - presumably cannabinoids - oils, and related 
compounds which accumulate between the head cells and the outer membrane 
(cuticle). When the gland matures, a nipple-like outpocket may form on the 
membrane from the pressure of the accumulating resin. The bulbous glands are 
found scattered about the surfaces of the above-ground plant parts. 
The second type of gland is much larger and more numerous than the bulbous 
glands. The are called "capitate," which means having a globular-shaped head. On 
immature plants, the heads lie flush or appear not to have a stalk and are 
called "capitate sessile." They actually have a stalk that is one cell high, 
although it may not be visible beneath the globular head. The head is composed 
of usually eight, but up to 16 cells, that form a convex rosette. These cells 
secrete a cannabinoid-rich resin which accumulates between the rosette and its 
outer membrane. This gives it a spherical shape, and the gland measures from 25 
to 100 um across. In fresh plant material about 80 to 90 percent of their 
contents will be cannabinoids, the rest primarily essential oils (146). 
During flowering the capitate glands that appear on the newly formed plant parts 
take on a third form. Some of the glands are raised to a height of 150 to 500 um 
when their talks elongate, possibly due to their greater activity. The stalk is 
composed mostly of adjacent epidermal tissue. These capitate-stalked glands 
appear during flowering and form their densest cover on the female flower 
bracts. They are also highly concentrated on the small leaves that accompany the 
flowers of fine marijuana varieties. Highest concentration is along the veins of 
the lower leaf surface, although the glands may also be found on the upper leaf 
surface on some varieties. The male flowers have stalked glands on the sepals, 
but they are smaller and less concentrated than on the female bracts. Male 
flowers form a row of very large capitate glands along the opposite sides of 
anthers. 
Capitate-stalked resin glands are the only ones visible without a microscope. To 
the naked eye, this covering of glands on the female flower bracts looks like 
talcum or dew sprinkled on a fuzzy surface. With a strong hand lens, the heads 
and stalks are distinct. Resin glands also can be seen on the anthers of the 
male flowers and on the undersides of the small leaves the intersperse the 
flower clusters. 
{Figure 17.  Upper surface of a small leaf, showing stalked glands.}
{Figure 18.  Resin glands on a stem lie close to the surface beneath the
cystolith hairs.  Hairs always point in direction of growing shoots.}
Resin glands are not visible until flowers form. The more obvious covering of 
white hairs seen on stems, petioles, and leaves are not resin glands. They are 
cystolith hairs of carbonate and silicate which are common to many plants. These 
sharp-pointed hairs afford the plant some protection from insects and make it 
less palatable to larger, plant-eating animals. 
In India, to make the finest quality hashish (nup), dried plants are thrashed 
over screens. Gland heads, stalks and trichomes collect in a white to golden 
powder which is then compressed into hashish (for hashmaking search section 21 
for "hash"). 
Resin rarely accumulates in the copious quantities people would lead you to 
believe. Actually, the plants form a cover of resin glands rather than a coating 
of resin. Usually this is no more apparent than for the female flowers to 
glisten with pin-points of light and for the leaves and stems to feel a bit 
sticky when you run your fingers over them. 
On some fine marijuana strains, resin may become obvious by the end of flowering 
and seed set. Resins occasionally secrete through pores in the membrane of gland 
heads. Usually secretion occurs many weeks after the stalked glands appear. The 
glands seem to empty their contents, leaving hollow spaces (vacuoles) in the 
stalk and head cells. After secretion, the glands cease to function and begin to 
degenerate. Gland heads, stalks, and trichomes become clumped together, and the 
whole flowering surface becomes a sticky mass. For reasons we'll go into later, 
this is not necessarily desirable. (see sections 20,21.) 
Small quantities of cannabinoids are present in the internal tissues of the 
plant. The bulk is found in small single cells (non-articulated laticifers) that 
elongate to form small, individual resin canals. The resin canals ramify the 
developing shoots, and penetrate the plant's conducting tissue (phloem). Minute 
clumps of resin found in the phloem are probably deposited by these resin 
canals. Other plant cells contain insignificant amounts of cannabinoids and 
probably a good 90 percent of the cannabinoids are localised in the resin 
glands. 
Cannabinoid synthesis seems to occur primarily in the head and apex of the stalk 
cells of the resin glands (26). Lacticifers and possibly other plant cells 
probably contribute by synthesising the simpler molecules that will eventually 
make up the cannabinoids. Biosynthesis (the way the plant makes the molecules) 
of the cannabinoids is believed to follow a scheme originally outlined by A.R. 
Todd in his paper "Hashish," published in 1946 (see Figure 19). In the 1960s the 
pathway was worked out by Raphal Mechoulam, and confirmed in 1975 by Dr. 
Shimomura and his associates. 
{Figure 19.  Possible biosynthesis of cannabinoids.}
Notice that all the cannabinoids are their acid forms with a (COOH) carboxyl 
group at C-2 in the aromatic ring. This group may also appear at C-4 and the 
compounds are called, for example, THC acid "A" and THC acid "B", respectively. 
The position of the carboxyl group does not affect the potency, but, in fact, in 
their acid forms the cannabinoids are not psychoactive. In fresh plant material, 
cannabinoids are almost entirely inn their acid forms. The normal procedure of 
curing and smoking the grass (heat) removes the carboxyl group, forming the gas 
CO2 and the psychoactive neutral cannabinoids. Removing the CO2 in important 
only if you plan to eat the marijuana. It is then necessary to apply heat 
(baking in brownies, for example) for the cannabinoids to become psychoactive. 
Ten minutes of baking marijuana at 200F is enough to convert the THC acids to 
neutral THC. 
The formation of CBG acid, from which all the other cannabinoids are formed, is 
initially made from much simpler compounds containing terpene units. The example 
here is olivetolic acid condensing with a terpene moiety called geranyl 
pyrophosphate. It is not known whether these are the actual or only precursors 
to CBG in the living plant. 
Terpenes and related substances are quite light and some of them can be 
extracted by steam distillation to yield the "essential oil" of the plant (from 
essence - giving the flavour, aroma, character). Over 30 of these related oily 
substances have been identified from Cannabis (143). On exposure to light and 
air, some of the polymerise, forming resins and tars. 
The cannabinoids are odourless; most of the sweet, distinctive, pleasant "minty" 
fragrance and taste of fresh marijuana comes from only five substances which 
make up only 5 to 10 percent of the essential oils: the mono- and 
sesqui-terpenes alpha- and beta-pinene, limonene, myrcene, and beta-phalandrene 
(144). These oily substances are volatile and enter the air quickly, dissipating 
with time. Subsequently, the marijuana loses much of its sweetness and minty 
bouquet. 
The essential oils constitute about .1 to .3 percent of the dry weight of a 
fresh marijuana sample, or on the order of 10 percent of the weight of the 
cannabinoids. Essential oils are found within the heads of the resin glands and 
make up about 10 to 20 percent of their contents in fresh material (146). They 
have also been detected in the resin canals (laticifers) (31). 
Different samples of Cannabis have essential oils of different composition. This 
is not surprising given the variability of the plant. Since substances found in 
the essential oils are, or are related to, substances that are the precursors of 
the cannabinoids, there is some chance that a relationship exists between a 
particular bouquet and cannabinoids content. No such relationship is yet known, 
but it has only been studied superficially. When connoisseurs sample the bouquet 
of a grass sample, they are basically determining whether it is fresh. Fresh 
grass mean fresh cannabinoids and less of these are likely to have been degraded 
to non-psychoactive products. 
2.4 Production of Cannabinoids by Cannabis
Why Cannabis produces cannabinoids and resins is a question probably every 
grower has wondered about. Supposedly, if you know, you could stimulate an 
environmental factor to increase cannabinoids production. Unfortunately, it does 
not follow that increasing a particular selective pressure will affect a plant's 
(phenotype) cannabinoids production. However, over a period of generations, it 
is possible that environmental manipulations can increase the overall 
cannabinoids concentrations in a population of plants. But even this procedure 
would work slowly compared to direct breeding by the farmer. 
From the microstructure of the resin glands and the complexity of the resin, it 
is apparent that Cannabis invests considerable energy in making and storing the 
cannabinoids. Obviously, the cannabinoids are not a simple by-product or 
excretory product. No doubt the cannabinoids and resins serve the plant in many 
ways, but probably they have more to do with biotic factors (other living 
things) rather than abiotic factors (non-living environment such as sunlight, 
moisture, etc.). 
The cannabinoids, resins, and related substances make up a complex and 
biologically highly active group of chemicals, a virtual chemical arsenal from 
which the plant draws its means for dealing with other organisms. This would 
apply especially to herbivores, pathogens, and competing plants. In the case of 
humans, the cannabinoids are an attractant. Some possible advantages to the 
plant are listed below, but no direct studies have been done on this question. 
Indeed, it is surprising that botanists have shown so little interest in this 
question; they have even gone out of their way to state their lack of interest. 
Possible Advantages of Cannabinoid Production 
  1. Obviously the cannabinoids are psychoactive and physiologically active in 
  many animals. This may dissuade plant-eating animals from eating the plant, 
  especially the reproductive parts. Many birds enjoy Cannabis seeds. But in 
  nature, birds will not bother young seeds, probably because they are encased 
  in the cannabinoids-rich bracts. In wild or weedy plants, when the seed is 
  mature it "shells out" and falls to the ground. Birds will eat the naked 
  seeds. However, matured seeds are quite hard. Many will not be cracked and 
  eventually will be dropped elsewhere, helping the plant to propagate. Bees and 
  other insects are attracted to the pollen. The cannabinoids and resins may 
  deter insects from feeding on pollen and developing seeds. Resin glands reach 
  their largest size on the anthers (which hold pollen) and bracts (which 
  contain the seed). {See plates 6, 7, 10 and 11.} 2. Terpenoid and phenolic 
  resins are known to inhibit germination of some seeds. Cannabis resins may 
  help Cannabis seedlings compete with other seedlings by inhibiting their 
  germination. 3. Many of the cannabinoids (CBD, CBG, CBC and their acids) are 
  highly active antibiotics against a wide range of bacteria (almost all are 
  gram +) (36,130,184). Crude resin extracts have been shown to be nematocidal 
  (36). (However, fungicidal activity is low.) 
Most of the explanations you've probably heard for resin production from both 
lore and scientists have to do with physical factors such as sunlight, heat, and 
dryness. Presumably the resin coats the plant, protecting it from drying out 
under physical extremes. These explanations make little sense in light of the 
resins' chemistry. 
The physical qualities of the glands and resins probably aid the plant in some 
ways. The sticky nature of resin may help pollen grains to adhere to the 
flowering mass and stigmas, or simply make the plant parts less palatable. And 
gland heads do absorb and reflect considerable sunlight, and so possibly protect 
the developing seed. For instance, gland heads are at first colourless (i.e., 
they absorb ultraviolet light). This screening of ultraviolet light, a known 
mutagen, may lower possible deleterious mutations. But physical properties seem 
to be secondary to the resins' chemical properties as functional compounds to 
the plant. 
2.5 Cannabis Chemotypes
All Cannabis plants produce some cannabinoids. Each strain produces 
characteristic amounts of particular cannabinoids. Strains differ in the total 
amounts they contain. Usually they average about three percent cannabinoids to 
dry weight, but concentrations range from about one to 12 percent cannabinoids 
in a cleaned (seeds and stems removed), dried bud. Strains also differ in which 
cannabinoids they produce. Based on which cannabinoids, Cannabis strains can be 
divided into five broad chemical groups.((Chemical classification based on work 
by Small et al (51))) The general trend is for plants to have either THC or CBD 
as the main cannabinoid. 
Type I 
  Strains are high in THC and low in CBD. This type represents some of the 
  finest marijuana strains. They usually originate from tropical zones below 30 
  degrees latitude, which in the north runs through Houston and New Orleans to 
  Morocco, North India, and Shanghai, and in the south through Rio de Janeiro, 
  South Africa, and Australia. Most of the high-quality marijuana from Mexico, 
  Jamaica, and Colombia sols in this country is this type; most of you will grow 
  this type. As with all five chemical types, type I comes in different sizes 
  and shapes. Most common are plant about 10 to 12 feet tall (outdoors), quite 
  bushy, with branches that grow outward to form the plant into a cone 
  (Christmas tree shape). Other tall varieties (to 18 feet) have branches that 
  grow upward (poplar-tree shaped - some Mexican, Southeast and Central Asian 
  varieties). A less common short variety (up to eight feet) develops several 
  main stems and the plants appear to sprawl (Mexico, India). 
Type II 
  This is an intermediate group, with high CBD and moderate to high THC. They 
  usually originate from countries bordering 30 degrees latitude, such as 
  Morocco, Afghanistan and Pakistan. In this country, this type of grass usually 
  comes from Afghani and Colombian varieties. Type II plants are quite variable 
  in the intensity and quality of the high they produce, depending on the 
  relative amounts of THC and CBD in the variety. Probably because of their high 
  CBD and overall resin content, these plants are often sued to prepare hashish 
  and other concentrated forms of marijuana. The most common varieties grow to 
  about eight to 12 feet and assume a poplar-tree shape with long branches that 
  grow upward from the stem base and much shorter branches toward the top. They 
  usually come from Turkey, Greece, and Central or Southeast Asia and 
  occasionally from Colombia and Mexico. Some varieties are shorter, about four 
  to eight feet at maturity, and very bushy with a luxuriant covering of leaves. 
  These usually originate from Nepal, northern India, and other parts of Central 
  Asia as well as North Africa. Other varieties appear remarkably like short 
  (five to seven feet) hemp plants, with straight, slender stems and small, 
  weakly developed branches (Vietnam). A common short variety, less than four 
  feet tall (Lebanon, N. Africa), forms a continuous dense cluster of buds along 
  its short stem. They appear remarkably like the upper half of more common 
  marijuana plants. 

{Figure 20.  Left: This Pakistani variety ("indica") reaches a height of
five feet (large leaves removed).  Right: Flowering top two months later.}
Type III 
  Plants are high in CBD and low in THC. These are often cultivated for hemp 
  fibre or oil seed. Usually they originate from countries north of 30 degrees 
  latitude. As marijuana they yield a low-potency grass and are considered 
  non-drug varieties. If you choose your seeds from potent grass, it will not be 
  this type. An example of these plants are Midwestern weedy hemps which are 
  often collected and sold for low-grade domestic grass. The high CBD content 
  can make you feel drowsy with a mild headache long before you feel high. These 
  plants are very diverse morphologically even when categorised by cultivated 
  types. Hemp plants are usually tell (eight to 20 feet) with an emphasis on 
  stem development and minimal branching. Starting from the base, long, even 
  internodes (stem portion from one set of leaves to the next pair) and opposite 
  phyllotaxy (see 3.2) cover a good portion of the stem. Some varieties form 
  long, sparse branches only on the upper portion of the stem (many Midwest 
  weeds). Other varieties (Kentucky hemp) are the familiar Christmas-tree shape. 

  Seed varieties are usually short (two to eight feet) and very bushy. Branches 
  on some are short, grow outward and are all of approximately the same length, 
  giving the plant a cylindrical shape. Some of the shorter (two to three feet) 
  seed varieties have undeveloped branches, and almost all of the seeds collect 
  in a massive cluster along the top portion of the stalk. Seed plants are often 
  the most unusual-appearing of Cannabis plants, and you won't find them in the 
  United States. 
  As expected, the figures for average THC in Midwestern weeds are quite low. 
  this is consistent with their reputation for low potency. But the range of THC 
  goes up to 2.37 percent in the Illinois study. This is comparable with some of 
  the higher-quality imported marijuana and is consistent with some people's 
  claims that Midwestern weeds provided them with great highs. 
Type IV
  Varieties that produce propyl cannabinoids in significant amounts (over five 
  percent of total cannabinoids) form a fourth group from both type I and II 
  plants. Testing for the propyl cannabinoids has been limited and most reports 
  do not include them. They have been found in plants from South Africa, 
  Nigeria, Afghanistan, India, Pakistan, and Nepal with THCV as high as 53.69 
  percent of total cannabinoids (136). They usually have moderate to high levels 
  of both THC and CBD and hence have a complex cannabinoid chemistry. Type IV 
  plants represent some of the world's more exotic marijuana varieties. 
A fifth type, based on the production of CBGM, which is not psychoactive, is 
found in northeastern Asia, including Japan, Korea and China. This type is not 
relevant to us and will not be mentioned again. 
There are many different techniques for sampling, extraction, and estimation of 
cannabinoids in plant material. To minimise differences among research groups, 
the above data (except for Midwestern weedy hemps) are taken from studies at the 
University of Mississippi at Oxford (66,119,136). 
Unfortunately, some of the best Colombian, Mexican and Thai varieties are not 
included in the data. Many of these have not been tested until recently, and the 
figures are not yet published. Under the system for testing at the University of 
Mississippi, the highest THC variety reached six to eight percent THC in a bud. 
These seeds originated from Mexico. 
{See Table 01 to 10.}
These five chemical types are not distinct entities; that is, each type contains 
several quite different-appearing varieties. Actually, varieties of different 
types may look more similar than varieties from the same type. But the ability 
to produce characteristic amounts of particular cannabinoids is genetically 
based. This means the each type contains certain genes and gene combinations in 
common, and in biological terms, the plants are called chemical genotypes. 
These types may be from virtually any country simply because of the plant's past 
and ongoing history of movement. the first three can be found in most countries 
where Cannabis is heavily cultivated, although marijuana plants (types I, II, 
IV) usually originate from lower latitudes nearer the equator. This may be 
simply explained in terms of cultural practices. Marijuana traditionally has 
been cultivated in southerly cultures such as India, Southeast and Central Asia, 
Africa; and in the West in Mexico, Colombia, Jamaica, and Central American 
countries. On the other hand, useful characteristics must exist before cultures 
can put them to use after selection. And the characteristic (drug or fibre) must 
maintain itself within the local environment (see 18.4). 
Non-drug types (type III) usually originate at higher latitudes with shorter 
growing seasons. A definite gradation exists for non-drug to drug types, 
starting in temperate zones and moving toward the equator. The same gradation 
may be found for the appearance of propyl cannabinoids toward the equator. This 
doesn't mean that the quality of the grass you grow depends on whether you live 
in the north or south, but that over a period of years and decades, a group of 
plants may drift toward either the drug or the non-drug type (either rich in THC 
or rich in CBD). 
The majority of the marijuana sold in the United States has less than one 
percent THC; and the bulk of this comes from Mexican and domestic sources. The 
highest percentages of THC in marijuana that we've seen are: Colombian (9.7), 
Mexican (13.2), Hawaiian (7.8), and Thai sticks (20.2; however, this is believed 
to be adulterated with hash oil). The percentages of THC reported vary greatly, 
because they depend on the particular method of sampling and estimation used. 
Five samples of Colombian Golds, bought in New York City and San Francisco for 
from $30 to $50 (1976) an ounce, averaged 2.59 percent THC and 1.27 percent CBN. 
The CBN represents an average of about one-third of the THC originally present 
in the fresh plant by the time it reaches American streets. This is one 
advantage that homegrowers have, since their marijuana is fresh. In fresh plant 
material, less than 10 percent of the THC will have been converted to CBN, as 
long as the material is properly harvested, cured, and stored. 
By the time hashish reaches the American market, THC content is usually at the 
low end of the ranges given here, usually between 1.5 and 4 percent THC. The 
darker outer layer of hashish is caused by deterioration. The inner part will 
contain the highest concentration of THC. 
The average range for hash oil and red oil is 12 to 25 percent when it is fresh. 
It is not uncommon for illicit hash oil to have more than 60 percent THC. 
However, light, as well as air, very rapidly decomposes THC in the oil form (see 
the section on "Storage" in section 21). You can't tell whether the oil will be 
wondrous or worthless unless you smoke it. 
The preparations listed in Tables 9 and 10 are relatively fresh compared to 
hashish on the American market. Total cannabinoids make up roughly 25 to 35 
percent by weight of hashish and resin preparations. Note that the data in these 
tables are relative concentrations. 
Table 10 -Relative Percentages of Major Cannabinoids in Hashish from Nepal 
Percentage(a) of THC HASHISH THC CBD CBN THCV CBDV CBV LOST(b) Sample 1 11.5 
35.9 22.1 5.7 12.5 12.3 66 Sample 2 3.4 41.1 24.8 3 11.9 15.8 88 Sample 3 5.5 
41.2 30.3 2.3 9.1 11.6 85 a Each row in these columns sums to 100% b Percentage 
of original THC lost as CBN
The very high figures for CBN in hashish indicate that much of the THC is 
converted to CBN because of processing and aging. During hashmaking many of the 
gland heads are broken and the THC is exposed to light and air. The figures in 
these tables are typical of what to expect for relative concentrations of THC in 
hashish on the American market. Actual concentrations are roughly one-fourth to 
one-third of these figures. 
Obviously, THC percentages for hashish and tinctures are not that high compared 
to fine marijuana. Hashish in the United States seldom lives up to its 
reputation. The best buy in terms of the amount of THC for the money is hash oil 
when it is high quality and fresh. More often a fine homegrown sinsemilla or 
sometimes a lightly seeded Colombian is the best investment. (Of course, the 
best value is always what you grow yourself.) 



Chapter Three
BEFORE CULTIVATION BEGINS
3.2 Choosing Seeds
Popular Market names of different grades of grass, such as Colombian commercial 
and Mexican regular, are familiar to growers, but each grade actually may 
encompass many different varieties. For example, there are Colombian Golds that 
are similar in most respects, but some varieties grow no taller than six feet. 
The more common types grow 12 to 15 feet under the same conditions. Some Oaxacan 
Cannabis forms several strong upright branches by maturity, and at a glance may 
seem to have several stems, yet more often, Oaxacan is conical-shaped and grows 
about 12 feet. 
Most of the fine marijuana sold in this country comes from type I plants with 
THC as the predominant cannabinoid. Type II plants are less common. You might 
recognise type II plants by the high. The grass takes longer before its effects 
are felt, but the high lasts much longer than with other marijuana. Type IV 
plants are the least common; this marijuana seldom reaches the general American 
market. This type will get you high after only a few tokes. Type III plants are 
considered non-drug varieties because they are predominantly CBD with little 
THC. The effects of CBD are not felt unless it is accompanied by a sizeable 
concentration of THC, such as in type II plants. However, a lot of marijuana 
from these plants is sold in the United States. Some Mexican and Jamaican 
regular and much of the low-grade domestic is harvested from type III plants. 
You may not be able to tell what type plant you're smoking, but you can tell 
what you like. Seeds from high-quality marijuana will grow into high-quality 
marijuana plants. If you like the grass you're smoking, you'll like the grass 
you grow. 
The name of your grass has little to do with potency and may have originated in 
the mind of some enterprising dealer. Always choose your seeds from what you 
consider to be the best grass. Don't be swayed by exotic names. If you are not 
familiar with grass of connoisseur quality, ask someone whose experience you 
respect for seeds. Smokers tend to save seeds from exceptional grass even if 
they never plan to plant them. 
The origin of your grass even if you knew it for certain, has little to do with 
wether it will be dynamite or worthless smoke. In both India(45) and Brazil, 
hemp is grown which is worthless for marijuana. Likewise, extremely potent 
marijuana plants grow which are useless for hemp fibre. These plants are 
sometimes found growing in adjacent fields. Most of the fine-quality marijuana 
varieties develop in those countries nearer to the equator. How much this had to 
do with environmental conditions or cultural practices is unknown. In either 
case, marijuana traffic has been so heavy that fine varieties now grow all over 
the world. For example, in the United States thousands of people now grow 
varieties from Mexico. These fine varieties originated in Asia and Africa, and 
many were brought to Mexican farmers by American dealers during the 1960s. As 
more farmers grew these new varieties, the quality of Mexican grass imported to 
the United States improved. Already people are speaking of varieties such as 
Maui Wowie and Kona Gold. 
The colour of the grass does not determine its potency. Marijuana plants are 
almost always green, the upper surface of the leaves a dark, luxuriant green, 
and the undersurface a lighter, paler green. Some varieties develop reds and 
purples along stems and leaf petioles. Occasionally, even the leaves turn 
red/purple during the last stages of growth (plate 6). Grasses termed "Red" more 
often get their colour from the stigmas of the female flowers, which can turn 
from white to a rust or red colour, giving the marijuana buds a distinct reddish 
tinge. The golds and browns of commercial grasses are determined by the 
condition of the plant when it was harvested - whether it was healthy (green) or 
dying (autumn colours). How the plants are harvested, cured, and stored also has 
a serious effect on colour. Commercial grasses from Colombia, Mexico, and 
Jamaica are often poorly cured and packed. Too much moisture is left in the 
grass, encouraging microbial decomposition; with warm temperatures, whatever 
green was left disappears, leaving the more familiar browns and golds. Bythe 
time they reach the United States, commercial grasses lose about five to 20 
percent of their weight in water loss and often smell mouldy or musty. 
Colour also depends on origin - varieties adapted to tropical or high-altitude 
areas have less chlorophyll and more accessory pigments, giving the plant their 
autumn colours (accessory pigments protect the plant from excessive sunlight). 
Varieties adapted to northern climates, where sunlight is less intense, have 
more chlorophyll and less accessory pigments. The dying leaves often turn light 
yellow, grey, or rust. Variations in pigment concentrations are also influenced 
by local light particularly the soil conditions under which the plants are 
grown. 
The taste of the smoke - its flavour, aroma, and harshness - also depends more 
on when the marijuana was harvested and how it was handled after it was grown 
than on the variety or environmental influences. 
You can detect subtle differences in the overall bouquet between freshly picked 
varieties. The environment probably influences bouquet too, but with most 
commercial grass the harvesting/storing procedures for outweigh these other, 
more subtle factors. A musty, harsh-smoking Colombian marijuana can give the 
mildest, sweetest, homegrown smoke when properly prepared. Don't be influenced 
by the marijuana's superficial characteristics. Choose seeds from the most 
potent grass. 
Grasses of comparable potency can yield plants of different potencies. This is 
because fine sinsemilla (homegrown, Hawaiians, Thai weeds, and some Mexicans) 
are carefully tended and harvested at about peak potency. They are also cured 
and packed well; so they are fresh when they are distributed in the American 
market. When you smoke them you are experiencing the at about its peak potency. 
The seeds you plant from this grass will produce plants, at best, of about equal 
potency. Sometimes they are slightly less simply because of differences in 
growing conditions. Colombian grasses are not usually harvested at their peak 
potency. A significant amount (20 percent and up) of the active cannabinoids 
(THC,CBD) are converted to much less active cannabinoids (CBN,CBS) or inactive 
ingredients (polymers-tars, resins, oils, etc.). This is also true of many 
Mexican and Jamaican grasses that are heavily seeded and poorly handled. 
Homegrown from this grass can produce plants of higher potency than the 
original, simply because the homegrown is fresh, and is harvested and cured well 
so that the THC content is at its peak. 
When choosing seeds you might consider the following Broad Generalisations. 
Mexican, Jamaican (if you can find goof Jamaican anymore), and homegrowns, 
including Hawaiians, often develop quickly and have a better chance of fully 
maturing in the shorter growing seasons over most of the north and central 
states. Colombian, African, and Southeast Asian varieties, such as Vietnam and 
Thai sticks (from Thailand and Japan), more often need a longer season to fully 
develop/ Under natural conditions they seldom flower in the short growing season 
that covers the northern United States. 
For indoor growers, the growing season is all year; so it doesn't matter if 
plants need longer to develop. Mexican and Jamaican plants usually reach full 
potency in about six months. Colombian and Southeast Asian varieties may need 
eight or nine months until they reach their maximum THC or general resin content 
under indoor conditions. 
The grass you choose should have a good stock of mature seeds. Thai weed and 
fine homegrowns (sinsemillas, which are by definition female flowers buds 
without seeds) may have no seeds at all but more often have a few viable seeds. 
Most Colombian and Mexican grasses contain between one and two thousand seeds 
per ounce bag or lid of grass. This may sound like an exaggerated figure, but 
it's not. Look at the photos in Figure 21 showing the yield from some Michoacan 
buds. The yield is 40 percent grass (1.22 grams, about three joints), 50 percent 
seeds (1.56 grams or 120 seeds), and 10 percent stems (0.3 grams). 
Relative to smoking material, seeds are heavy. Colombian grasses average about 
50 percent seeds by weight. A film canister holds about 1,200 Colombian seeds. 
{Figure 21, Seeded buds often contain more weight in seeds than grass} 
Depending on the variety, healthy mature seeds (which are botanically achene 
nots) vary in size between 1/12 and 1/4 inches in length. From any variety, 
choose seeds that are plump and well-formed with well-developed colour. Seed 
colours range from a buff through a dark brown, and from light grey to almost 
black colours. Often seeds are mottled with brown or black spots, bars, or lines 
on a lighter field {plate 11}. Green or whitish seeds are usually immature and 
will germinate feebly if at all. Fresh seeds have a waxy glimmer and a hard, 
intact shell. Shiny, very dark brown or black seeds often mean the contents are 
fermented and the embryo is dead. Fermented seeds crush easily with finger 
pressure and are hollow or dust inside. Seeds that are bruised or crushed are 
also not viable. This happens to some seeds when grass is compressed or bricked. 

Fresh, fully matured Cannabis seeds have a high rate of germination; 90 percent 
or better is typical. It is sometimes helpful to have an idea of how many seeds 
to expect to germinate. You can tell simply by placing a sample number between 
wet paper towels which are kept moist. Most of the seeds that germinate do so 
within a few days of each other. After a week or two, count how many of the 
original seeds germinated. This gives you a rough idea of what to expect from 
the seeds when planted. 
The viability of seeds gradually declines with time; left in the ground, only 40 
percent may germinate next season. Seeds are n ideal pray for many fungi, which 
are responsible for most of their deterioration. In a warm (70F or over) and 
humid atmosphere, fungi rapidly destroy seeds. If kept cool and dry in an 
airtight container, seeds stored in this way and left in the buds also maintain 
high viability for over two years. 
3.3 CANNABIS LIFE CYCLE
Marijuana plants may belong to any one of a number of varieties which follow 
somewhat different growth patterns. The following outline describes the more 
common form of growth. Differences between varieties can be thought of as 
variations on this standard theme. 
Cannabis is an annual plant. A single season completes a generation, leaving all 
hope for the future to the seeds. The normal life cycle follows the general 
pattern described below. 
Germination
With winter past, the moisture and warmth of spring stir activity in the embryo. 
Water is absorbed and the embryo's tissues swell and grow, splitting the seed 
along its suture. The radical or embryonic root appears first. Once clear of the 
seed, the root directs growth downward in response to gravity. Meanwhile, the 
seed is being lifted upward by growing cells which form the seedling's stem. Now 
anchored by the roots, and receiving water and nutrients, the embryonic leaves 
(cotyledons) unfold. They are a pair of small, somewhat oval, simple leaves, now 
green with chlorophyll to absorb the life-giving light. Germination is complete. 
The embryo has been reborn and is now a seedling living on the food it produces 
through photosynthesis. The process of germination is usually completed in three 
to 10 days. 
Seedling
The second pair of leaves begins the seedling stage. They are set opposite each 
other and usually have a single blade. They differ from the embryonic leaves by 
their larger size, spearhead shape, and serrated margins. With the next pair of 
leaves that appears, usually each leaf has three blades and is larger still. A 
basic pattern has been set. Each new set of leaves will be larger, with a higher 
number of blades per leaf until, depending on variety, they reach their maximum 
number, often nine or 11. The seedling stage is completed within four to six 
weeks. 
Vegetative Growth
This is the period of maximum growth. The plant can grow no faster than the rate 
that its leaves can produce energy for new growth. Each day more leaf tissue is 
created, increasing the overall capacity for growth. With excellent growing 
conditions, Cannabis has been known to grow six inches a day, although the rate 
is more commonly one to two inches. The number of blades on each leaf begins to 
decline during the middle of the vegetative stage. Then the arrangement of the 
leaves on the stem (phyllotaxy) changes from the usual opposite to alternate. 
The internodes (stem space from one pair of leaves to the next, which had been 
increasing in length) begin to decrease, and the growth appears to be thicker. 
Branches which appeared in the axils of each set of leaves grow and shape the 
plant to its characteristic form. The vegetative stage is usually completed in 
the third to fifth months of growth. 
Preflowering
This is a quiescent period of one to two weeks during which growth slows 
considerably. The plant is beginning a new program of growth as encoded in its 
genes. The old system is turned off and the new program beings with the 
appearance of the first flowers. 
Flowering
Cannabis is dioecious: each plant produces either male or female flowers, and is 
considered either a male or female plant. Male plants usually start to flowers 
about one month before the female; however, there is sufficient overlap to 
ensure pollination. First the upper internodes elongate; in a few days the male 
flowers appear. The male flowers are quite small, about 1/4 inch, and are pale 
green, yellow, or red/purple. They develop in dense, drooping clusters (cymes) 
capable of releasing clouds of pollen dust. Once pollen falls, males lose vigour 
and soon die. 
The female flowers consists of two small (1/4 to 1/2 inch long), fuzzy white 
stigmas raised in a V sign and attached at the base to an ovule which is 
contained in a tiny green pod. The pod is formed from modified leaves (bracts 
and bracteoles) which envelop the developing seed. The female flowers develop 
tightly together to form dense clusters (racemes) or buds, cones, or colas (in 
this book, buds). The bloom continues until pollen reaches the flowers, 
fertilising them and beginning the formation of seeds. Flowering usually lasts 
about one or two months, but may continue longer when the plants are not 
pollinated and there is no killing frost. 
Seed Set
A fertilised female flower develops a single seed wrapped in the bracts. In 
thick clusters, they form the seed-filled buds that make up most fine imported 
marijuana. After pollination, mature, viable seeds take from 10 days to five 
weeks to develop. When seeds are desired, the plant is harvested when enough 
seeds have reached full colour. For a fully-seeded plant this often takes place 
when the plant has stopped growth and is, in fact, dying. During flowering and 
seed set, various colours may appear. All the plant's energy goes to 
reproduction and the continuance of its kind. Minerals and nutrients flow from 
the leaves to the seeds, and the chlorophylls that give the plant its green 
colour disintegrate. The golds, browns, and reds which appear are from accessory 
pigments that formerly had been masked by chlorophyll. 
Figure 30 THC potency through various growth stages in the male and female
plant
About Plants Generally
Plants use a fundamentally different "life strategy" from animals. Animals are 
more or less self-contained units that grow and develop to predetermined forms. 
They use movement and choice of behaviour to deal with the changing 
environments. Plants are organised more as open systems - the simple physical 
characteristics of the environment, such as sunlight, water, and temperature, 
directly control their growth, form, and life cycles. Once the seed sprouts, the 
plant is rooted in place and time. Since growth is regulated by the environment, 
development is on accordance with the plant's immediate surroundings. When a 
balance is struck, the strategy is a success and life flourishes. 
Behaviour of a plant is not a matter of choice; it is a fixed response. On a 
visible level the response more often than not is growth, either a new form of 
growth, or specialised growth. By directly responding, plant in effect "know," 
for example, when to sprout, flower, or drop leaves to prepare for winter. 
Everyone has seen how a plant turns toward light or can bend upward if it its 
stem is bent down. The plant turns by growing cells of different length on 
opposite sides of the stem. This effect turns or right the plant. The stimulus 
in the first case is light, in the second gravity, but essentially the plant 
responds by specialised growth. It is the same with almost all facets of a 
plant's live - growth is modified and controlled by the immediate environment. 
The influence of light, wind, rainfall, etc., interacts with the plant (its 
genetic make-up or genotype) to produce the individual plant (phenotype). 
The life cycle of Cannabis is usually complete in four to nine months. The 
actual time depends on variety, but it is regulated by local growing conditions, 
specifically the photoperiod (length of day vs night). Cannabis is a long-night 
(or short-day) plant. When exposed to a period of two weeks of long nights - 
that is, 13 or more hours of continuous darkness each night - the plants respond 
by flowering. This has important implications, for it allows the grower to 
control the life cycle of the plant and adapt it to local growing conditions or 
unique situations. Since you can control flowering, you control maturation and, 
hence, the age of the plants at harvest. 
3.4 PHOTOPERIOD AND FLOWERING
For the marijuana grower the most important plant/environment interaction to 
understand is the influence of the photoperiod. The photoperiod is the daily 
number of hours of day (light) vs. night (dark). In nature, long nights signal 
the plant that winter is coming and that it is time to flowers and produce 
seeds. As long as the day-length is long, the plants continue vegetative growth. 
If female flowers do appear, there will only be a few. These flowers will not 
form the characteristic large clusters or buds. If the days are too short, the 
plants flowers too soon, and remain small and underdeveloped. 
The plant "senses" the longer nights by a direct interaction with light. A 
flowering hormone is present during all stages of growth. This hormone is 
sensitive to light and is rendered inactive by even low levels of light. When 
the dark periods are long enough, the hormones increase to a critical level that 
triggers the reproductive cycle. Vegetative growth ends and flowering begins. 
The natural photoperiod changes with the passing of seasons. In the Northern 
Hemisphere, the length of daylight is longest on June 21. Day-length gradually 
decreases until it reaches its shortest duration on December 22. The duration of 
daylight then begins to increase until the cycle is completed the following June 
21. Because the Earth is tilted on its axis to the sun, day-length also depends 
on position (or latitude) on Earth. As one moves closer to the equator, changes 
in the photoperiod are less drastic over the course of a year. At the equator (0 
degrees altitude) day length lasts about 12.5 hours on June 21 and 11.5 hours on 
December 22. In Maine (about 45 degrees north), day-length varies between about 
16 and nine hours. Near the Arctic Circe on June 21 there is no night. On 
December 22 the whole day is dark. The longer day-length toward the north 
prevents marijuana from flowering until later in the season. Over most of the 
northern half of the country, flowering is often so late that development cannot 
be completed before the onset of cold weather and heavy frosts. 
The actual length of day largely depends on local conditions, such as cloud 
cover, altitude, and terrain. On a flat Midwest plain, the effective length of 
day is about 30 minutes longer than sunrise to sunset. In practical terms, it is 
little help to calculate the photoperiod, but it is important to realise how it 
affects the plants and how you can use it to you advantage. 
Cannabis generally needs about two weeks of successive long nights before the 
first flowers appear. The photoperiod necessary for flowering will vary slight 
with (1) the variety, (2) the age of the plant, (3) its sex, and (4) growing 
conditions. 
  1. Cannabis varieties originating from more northerly climes (short growing 
  seasons) react to as little as nine hours of night. Most of these are hemp and 
  seed varieties that are acclimated to short growing seasons, such as the weedy 
  hemps of Minnesota or southern Canada. Varieties from more southerly latitudes 
  need longer nights with 11 to 13 hours of darkness. Since most marijuana 
  plants are acclimated to southerly latitudes, they need the longer nights to 
  flower. To be on the safe side, if you give Cannabis plant dark periods of 13 
  or more hours, each night for two weeks, this should be enough to trigger 
  flowering. 2. The older a plant (the more physiologically developed), the 
  quicker it responds to long nights. Plants five or six months old sometimes 
  form visible flowers after only four long nights. Young marijuana plants (a 
  month or so of age) can take up to four weeks to respond to long nights of 16 
  hours. 3. Both male and female Cannabis are long-night plants. Both will 
  flower when given about two weeks of long nights. The male plant, however, 
  will often flower fully under very long days (18 hours) and short nights (six 
  hours). Males often flowers at about the same time they would if they were 
  growing in their original environment. For most marijuana plants this occurs 
  during the third to fifth month. 4. Growing conditions affect flowering in 
  many ways (see Chapter 12). Cool temperatures (about 50F) slow down the 
  flowering response. Cool temperatures or generally poor growing conditions 
  affect flowering indirectly. Flower development is slower, and more time is 
  needed to reach full bloom. Under adverse conditions, female buds will not 
  develop to full size. 
Applications of Photoperiod
The photoperiod is used to manipulate the plants in two basic ways:
  1. By giving long dark periods, you can force plants to flower. 2. By 
  preventing long nights, using artificial light to interrupt the dark period, 
  you can force the plants to continue vegetative growth. 
Outdoors
Most marijuana plants cultivated in the United States begin to flower by late 
August to early October and the plants are harvested from October to November. 
For farmers in the South, parts of the Midwest, and West Coast, this presents no 
problem and no special techniques are needed for normal flowering. 
In much of the North and high-altitude areas, many varieties will not have time 
to complete flowering before fall frosts. To force the plants to flower earlier, 
give them longer night periods. If the plants are in containers, you can simply 
move them into a darkened area each evening. Plants growing in the ground can be 
covered with an opaque tarpaulin, black sheet plastic, or double or 
triple-layers black plastic trash bags. Take advantage of any natural shading 
because direct sunlight is difficult to screen completely. For instance, if the 
plants are naturally shaded in the morning hours, cover the plants each evening 
or night. The next morning you uncover the plants at about eight to nine 
o'clock. Continue the treatment each day until all the plants are showing 
flowers. This usually takes two weeks at most, is the plants are well developed 
(about four months old). For this reason, where the season starts late, it is 
best to start the plants indoors or in cold frames and transplant outdoors when 
the weather is mild. This in effect lengthens the local growing season and gives 
the plants another month or two to develop. By the end of August the plants are 
physiologically ready to flower; they sometimes do with no manipulation of the 
photoperiod. More often female plants show a few flowers, but the day-length 
prevents rapid development to large clusters. The plants seem in limbo - caught 
between vegetative growth and flowering. The natural day-length at this time of 
year will not be long enough to reverse the process, so you can discontinue the 
treatment when you see that the new growth is predominantly flowers. 
In areas where frosts are likely to occur by early October, long-night 
treatments may be the only way you can harvest good-sized flower clusters. These 
clusters, or buds, are the most potent plant parts and make up the desired 
harvest. Forcing the plants to flowers early also means development while the 
weather is warm and the sun is shining strongly. The flower buds will form much 
faster, larger and reach their peak potency. A good time to start the treatments 
is early to middle August. This allows the plants at least four weeks of 
flowering while the weather is mild. 
Another reason you may want to do this is to synchronise the life cycle of the 
plants with the indigenous vegetation. In the northeast and central states, the 
growing season ends quite early and much of the local vegetation dies back and 
changes colour. Any marijuana plants stick out like green thumbs, and the crop 
may get ripped off or busted. Plants treated with long nights during late July 
will be ready to harvest in September. 
Outdoors, growers should always plant several varieties, because some may 
naturally flower early, even in the northern-most parts of the country. These 
early-maturing varieties usually come from Mexican, Central Asian, and homegrown 
sources. By planting several varieties, many of you will be able to find or 
develop an early-maturing variety after a season or two. This, of course, is an 
important point, because it eliminates the need for long-night treatments. 
Preventing Flowers
Manipulation of the photoperiod can also prevent the plants from flowering until 
a desired time. For example, in Hawaii the weather is mild enough to grow winter 
crops. The normal summer crop is harvested anytime from September to 
mid-November. The winter crop is generally planted from October to December. 
Because the winter days are so short, the plants flower almost immediately, 
usually within two month. The plants are harvested in their third or fourth 
month and yield about 1/4 the yield of summer plants. A large Hawaiian female 
can yield a pound of buds. Most of the plant's overall size is reached while it 
is vegetatively growing. By interrupting the night period with light, you can 
keep these plants vegetatively growing for another month, yielding plants of 
about twice the size. 
The amount of light needed to prevent flowering is quite small (about .03 foot 
candles95 - on a clear night the full moon is about .01 foot candles). However, 
each plant mist be illuminated fully, with the light shining over the whole 
plant. This might be accomplished with either electric light or a strong 
flashlight. The easiest way is to string incandescent bulbs, keeping them on a 
timer. The lights need be turned on for only a flash at any time during the 
night period, from about 9:00 pm to about 3:00 am. The interrupts the long night 
period to less then nine hours. Start these night treatments each night or two, 
until you want the plants to flower. 
Indoors
Natural Light
Indoors, the growing season lasts all year. The night period is much easier to 
control. Sometimes people grow plants in their windows for more than a year 
without any female flowers ever forming. This is because household lamps are 
turned on sometime at night, illuminating the plants. Under natural light 
exclusively, indoor plants flower at about the same time they would outdoors 
(sometime a bit sooner because it is warmer indoors or the plants may be 
shaded). When plants are well developed and you want them to flower, make sure 
that no household lamps or nearby street lamps are shining on them. During late 
fall and winter, the natural day-length is short enough for the plants to flower 
naturally, if you simply keep off any lights at night that are in the same room 
as the plants. If you must use light, use the lowest wattage possible, such as a 
six-watt bulb. (The hormone is also least sensitive to blue light.) Shield the 
light away from the plants. Or shield the plants from any household light with 
aluminium foil curtains. Once the flowers are forming clusters, you can 
discontinue the dark treatments, especially if it is more convenient. However, 
if it is too soon (when you see only a few random flowers), household lights can 
reverse the process. 
By using natural light, you can grow indoor crops all year. The winter light is 
weak and the days are short, so it is best to use artificial lights to 
supplement daylight, as well as to extend the photoperiod. The extra light will 
increase the growth rate of the plants and hence size and yield. You should 
allow winter crops to flower during late January or February, using the natural 
photoperiod to trigger flowering. If you wait until spring, the natural light 
period will be too long and may prevent flowering. 
Artificial Lights
Under artificial light the photoperiod is, of course, any length you wish. The 
most popular way to grow with artificial lights is the harvest system. Start the 
plants under long light periods of from 16 to 18 hours daily. After the plants 
have reached a good size, usually between three and six months, shorten the 
light cycle to about 12 hours to force flowering. 
To decide exactly when to force the plants to flower, let their growth be the 
determinant. If male plants are showing their flowers, then the females are 
physiologically ready to flower. Most of the plant's overall height is achieved 
during vegetative growth. Some varieties, of course, are smaller and grow more 
slowly than others. Wait until the plants are nearing the limits of the height 
of the garden or are at least five feet tall. This is large enough to support 
good flower development and return a good yield. If you turn down the light 
cycle when the plants are young and small, you'll harvest much less grass 
because the plants simply can't sustain a large number of flowers. 
Some leaf growers prefer a continuous growth system, emphasising leaf growth and 
a continuous supply of grass. The light cycle is set for 18 to 24 hours a day. 
This prevents flowering and the plants continue their rapid vegetative growth. 
Growing shoots and leaves are harvested as used, and plants are removed whenever 
they lose their vigour and growth has noticeably slowed. New plants are started 
in their place. In this way, there will be plants at different growth stages, 
some of which will be in their rapid vegetative growth stage and will be quite 
potent. Male plants and some females eventually will form flowers, but the 
females will not form large clusters. People often use this system when the 
lights are permanently fixed. Small plants are raised up to the lights on tables 
or boxes. This garden never shuts down and yields a continuous supply of grass. 
3.5 INHERENT VARIATIONS IN POTENCY
The potency of a particular marijuana sample will vary because of many factors 
other then the variety. Many of these have to do with the natural development of 
the plants and their resin glands. Environmental factors do affect potency but 
there are large differences in any variety. These inherent factors must be 
explained before we can talk of factors outside the plant that affect relative 
potency. Strictly environmental effects are discussed in Chapter 19. 
Variations in Potency Within Varieties
There are noticeable differences in THC concentrations between plants of the 
same variety. Differences are large enough so that you can tall (by smoking) 
that certain plants are better. This is no news to homegrowers, who often find a 
particular plant to be outstanding. Five-fold differences in THC concentration 
have also shown up in research. However, when you consider a whole group of 
plants of the same variety, they're relatively similar in cannabinoid 
concentrations. Type II plants are the most variable, with individual plants 
much higher than other in certain canninbinoids. 
Variations by Plant Part
The concentration of cannabinoids depends on the plant part, or more 
specifically, the concentration and development of resin glands to plant part. 
The female flower bracts have the highest concentration of resin glands and are 
usually the most potent plant parts. Seeds and roots have no resin glands. These 
shoe no more than traces of canninbinoids. Smoke seeds will give you a headache 
before you can get high. If you got high on seeds, then there were probably 
enough bracts adhering to the seeds to get you high. {Figure 29 The highest 
concentration of stalked resin glands forms a cover on the female flower bracts 
Resin glands beneath cystolith hairs on a leaf petiole} 
Here are the potencies, in descending order, of the various plant parts: 
        1. Female flowering clusters.  In practice you don't separate hundreds
        of tiny bracts to make a joint.  The whole flowering mass (seeds removed),
        along with small accompanying leaves, forms the material.
	2. Male flower clusters.  These vary more in relative potency depending on
        the strain (see "Potency by Sex," below).
	3. Growing shoots.  Before the plants flower, the vegetative shoots (tips)
        of the main stem and branches are the most potent plant parts.
	4. Leaves (a) that accompany flowers (small);
                  (b) along branches (medium);
                  (c) along main stem (large).
                Generally, the smaller the leaf is, the more potent it can be.
	5. Petioles (leaf stalks).  Same order as leaves.
	6. Stems.  Same order as leaves.  The smaller the stem (twig), the
        higher the possible concentration of cannabinoids.  Stems over 1/16"
        in diameter contain only traces of cannabinoids and are not worth
        smoking.  The small stems that bear the flowers can be quite potent.
	7. Seeds and Roots.  Contain only traces (less then .01 percent) and
        are not worth smoking or extracting.
        
This order is fairly consistent. The exceptions can be the small leaves that 
accompany male flowers, which are sometimes more potent than the flowers 
themselves. The growing shoots are sometimes more potent than the mature female 
flowers. 
Samples of pollen show varying amounts of cannabinoids. Resin glands are found 
inside the anthers, alongside the developing pollen grains, and form two rows on 
opposite sides of each anther. Pollen grains are smaller than the heads of large 
resin glands ({see Plate 7}), and range from 21 to 69 micrometres in diameter21. 
A small amount of resin contaminates the pollen when glands rupture, but most of 
the THC in pollen samples comes from gland heads that fall with pollen when the 
flowers are shaken to collect it. One study, using pollen for the sample, found 
concentrations of up to 0.96 percent THC, more then enough to get you high79. 
Potency by Position on Plant
The potency of marijuana on any plant increases toward the top of the plant, the 
topmost bud being the most potent. The bottommost leaves on the main stem are 
the least potent of the useable material. Along branches there is a less steep 
THC gradient increasing to the growing tip. 
The ratios in Table 11 are representative of high-quality marijuana varieties. 
Plant no. 2 is an exception, with four percent THC in its lower leaves, a figure 
comparable to high-quality Colombian and Mexican buds in commercial grass. 

Table 11 - Relationship of THC Content to Leaf Position (68)

Percentage of THC by weight of Leaf from Position on plant
Plant                       No. 1 (SP-5)   NO.2 (SP-5)     NO.3 (UNC-335)
Top                         6.1            6.9             4.8
Middle                      3              5.5             3.1
Bottom                      0.8            4               1.5
Ratio (gradient)            8:4:1          1.7:1.4:1       3:2:1
Notice the large difference in the gradients of Plants no. 1 and 2, which are 
from the same variety (SP-5). Like almost all characteristics of these plants, 
considerable variation occurs even among sibling. Our experience is that 
generally the better the quality of the variety, the steeper the gradient: in 
other words, the bigger the difference between top and bottom leaves. For 
example, the plants given here are high-quality type I varieties. Plant no. 1 is 
more typical, with its steep gradient, than no.2, where the gradient is much 
less pronounced. Lower-quality varieties generally do not have as steep a 
gradient and the ratios would look more like that of Plant no. 2. 
Potency by Sex
Although marijuana lore claimed the female to be the more potent, scientists 
disclaimed this. But there is some truth to both sides. In fine marijuana 
varieties, male and female leaves average about the same in cannabinoid 
concentrations. Either a male or a female individual may have the highest 
concentration in any particular case. The largest variation is in comparing the 
flowers. Male flowers may be comparable to the females, or they may not even get 
you high. It seems that the higher the quality of the grass, the better the male 
flowers will be. In fine type I plants, male flowering clusters usually approach 
the potency of the female. In low-quality type III varieties females are usually 
more potent (20 to 30 percent) than the males. 
Type II plants are the most variable, with large differences among individual 
plants. But the trend is for the females to average about 20 percent high in 
potency of leaves and flowers. 
Table 12 - Relative Potencies of Male and Female Plants (66)

                            Percentage by Weight (b) of
COUNTRY OF ORIGIN  SEX (a)        THC      CBD (C)  TYPE PLANT
Mexico             M              3.7     0.86          I
                   F              3.7     0.35
India              M              4.3     0.12          I
                   F             1.78     0.19
Thailand           M              3.2     0.08          I
                   F              3.2     0.42
India              M             0.81      2.1          II
                   F              1.3     0.89
Pakistan           M             1.37     1.24          II
                   F             0.71      1.5
Turkey             M             0.84     2.11          II
                   F             0.92     1.33
India              M             0.15      2.2         III
                   F             0.12      1.2
Poland             M             0.04     0.97         III
                   F             0.06      1.1

a) M, male (staminate); F, female (pistillate). (b) Of flowering mass
with accompanying leaves. (c) Includes CBC. _
Potency by Age
In general, the longer the life cycle of the plant, the more the concentration 
of cannabinoids increases, as long as the plant stays health and vigorous. 
Actually, it is the development of the plant, rather than chronological age, 
that determines this difference in potency. A plant that is more developed or 
more mature is generally more potent. 
Because you decide when to plant and/or can control the photoperiod, you also 
control when the plants flowers and, hence, the overall age at maturity. A 
six-month-old plant will generally be better than a four-month-old plant, both 
of which are flowering. Plants eight months old will usually be more potent than 
six-month-old plants. Most indoor growers plan their gardens to be about five to 
eight months old at harvest. Healthy plants can be extended to about 10 months. 
Plants older than 10 months often develop abnormally. There is usually a decline 
in vigour and a loss in potency. But some growers have decorative plants several 
years old. 
Outdoor growers more often simply allow the plants to develop according to the 
local growing conditions which will govern their development and flowering time. 
Where the growing season is short, some growers start the plants indoors and 
transplant when the local growing season begins. This gives the plants a longer 
growing season. 
One reason female plants are considered more potent is because of age. Males 
often flower in four to five months and die, while the females may continue to a 
ripe old age of eight or nine months, especially when they are not pollinated. 
Potency by Growth Stage
Although then general trend is for the cannabinoid concentration to increase 
with age, this is not a matter of the simple addition or accumulation of 
cannabinoids. The concentration of cannabinoids changes with the general 
metabolic rate of the plant, and can be related to the plant's growth pattern or 
life cycle. Figure 30 shows a hypothetical curve following the concentration of 
THC from the upper leaves and growing tips of a male and female plant. 
Notice that THC increases immediately with germination and establishment of the 
seedling, and continues to rise until the plant enters its vegetative stage. At 
this point, the plant is well-formed, with a sturdy stem, and no longer looks 
fragile. As the plant;s rate of growth increases, there is a corresponding rise 
in THC that continues throughout the vegetative stage until a plateau is 
reached. Before the plateau is reached the arrangement of leaves on the stem 
(phyllotaxy) changes from opposite to alternate. The plateau is maintained until 
the plant's rapid growth all but stops and the plant has entered preflowering. 
By this time, the branches have formed the plant to its characteristic shape. 
Preflowering lasts about one to two weeks, during which THC concentration falls 
until the appearance of the first flowers. 
For the male plant, preflowering ends with renewed growth. This lengthens the 
uppermost internodes and the first male flower buds appear. THC immediately 
increases with the development of the male flower clusters, and reaches its peak 
when most of the flowers are fully formed and a few are beginning to release 
pollen. After pollen release, the male normally loses vigour and THC content 
slowly declining until the plant is cured and stored. 
Female plants reach their maximum THC when the plants are in full bloom. Full 
bloom is when the plant has filled out with well-formed flower clusters, but 
flowers are still slowly forming. Most of the stigmas will still be white and 
healthy. 
Flowering lasts anywhere from two to 10 weeks, depending on whether the plants 
are pollinated or not, as well as on variety and the environment. (See Chapter 
20 for details.) THC content declines as the formation of new flowers slows and 
the majority of the stigmas begin to brown. The only changes you may see in the 
plants are the maturation of the seeds and the loss of green colour in the 
leaves and flowers. In some cases the plant's apparent resin (its look and feel) 
increases during the last few weeks of life while the THC concentration is still 
declining. 
You may feel that you should only pick marijuana when the plants are in full 
bloom, but this is not the case. Think of the garden as a continuous supply of 
grass. You can never be sure of the fate of your plants. The biggest problem 
with outdoor growing is that there is a good chance that the plants will be 
ripped off before you plan to harvest. It is much better to harvest grass during 
the course of a season, assuring yourself a return for your efforts. For 
example, during the third month of growth, you could cut back the growing tips, 
which should be quite potent, often more potent than Figure 30 suggests. This 
doesn't mean there will be less to harvest at season's end. In fact, the plant 
will be forced to develop its branches, possible yielding a larger plant. 
Common sense tells you that it is always best to test one sample before you 
harvest. By taking one tip, curing and smoking, you'll know whether it's 
worthwhile to harvest more at that time or to wait longer. When a tip is about 
equal to its parents' potency, then definitely harvest more growing tips. This 
peak high often occurs during the middle to late rapid, vegetative-growth stage. 

The reader should keep in mind that Figure 30 serves only as an example. 
Chronological age is not as important as the physiological age of the plant. In 
this graph, the life of the plants is about six months. But the life cycle 
depends on the particular variety and the growing conditions, which strongly 
influence the rate of development. (For details on how to use the graph, see 
Chapter 20.) The important facts that the reader should get from the graph are 
that the potency of the grass can decrease as well as increase during the 
plant's life cycle. Actual studies of the cyclic variations in potency over the 
course of a season have shown much more complicated rhythms, with many more 
peaks and valleys then here 71,74,80,86,92. Most varieties will more or less 
follow a growth pattern as described. Changes in the plant's development, such 
as phyllotaxy and growth rate, are cues to changes in THC concentration. 
Secondly, the growing tips of the main stem and branches can be very potent. 
Growers do not have to wait until flowers form to harvest top-quality smoke. 
  3.6 Cultivation: Indoors or Outdoors?
The basic elements of the environment (light, water, air, and soil) provide 
plants with their fundamental needs. These environmental factors affect the 
growth rates of plants, as well as their life cycles. If one factor is 
deficient, growth rate and vigour will wan regardless of the other three. For 
instance, with low light, the growth will be limited no matter how fertile and 
moist the soil is. In the same sense, if soil minerals are scarce, the growth 
rate will be limited no matter how you increase the light. 
Photosynthesis
Cannabis, like all green plants, manufacturers its food through the process 
photosynthesis. Unlike animals, which depend on pre-formed food for survival, 
plants can use energy from light to form food (carbohydrates) from simple 
inorganic molecules absorbed from the air and soil. 
Plants absorb light energy through pigments that are concentrated in the leaf 
cells. These pigments are also found in most of the aboveground parts of the 
plant. The most abundant pigment is chlorophyll, which gives the plants their 
green colour. The energy absorbed is stored in chemical compounds such as ATP 
and NADPH2. ((ATP, adenosine-triphosphate; NADPH2, 
nicotinamide-adenine-dinucleotide-phosphate.)) These are storage/transfer 
compounds that function to transfer energy and matter in the living system. ATP 
transfers energy that fuels the reactions for the making of carbohydrates as 
well as most other metabolic functions. NADPH2 transfers electrons, usually as 
hydrogen, for the synthesis of carbohydrates as well as other compounds. 
The raw material for the synthesis of carbohydrates (CH2O)n comes from carbon 
dioxide (CO2) and water (H2O). Carbon dioxide is absorbed primarily from the 
air, but can also be absorbed from the soil and secondarily from the air. 
	Photosynthesis is summarised as follow:
	light energy ------- ATP + NADPH2
	CO2 + H2O    ------- (CH2O)n + O2
For more complex bio-molecules such as amino acids and proteins, the plant 
absorbs minerals (including nitrogen, phosphorus, and sulfur) from the soil. 
Carbohydrates provide food energy for the plant using processes similar to those 
that occur in humans. They also form the basic building blocks for plant 
tissues. For example, the sugar glucose (CH2O)6 is strung and bonded to farm 
long chains of cellulose, the most abundant organic compound on earth. About 80 
percent of the structure of the plant's cells is made from cellulose. 
The plant is a living thing existing in a holistic world; a myriad of factors 
affect its life. However, good cultivation techniques require attention to only 
four basic growth factors. With this accomplished, the plants will do the rest. 
As grower, your strategy is to bring out the plant's natural qualities. The 
cannabinoids are natural to the plants. Seeds from potent marijuana grow into 
potent marijuana plants when they are nurtured to a full and healthy maturity. 
Since most marijuana plants are adapted to tropical or semitropical climates, it 
is up to the grower to make the transition to local growing conditions 
harmonious. The requires sensible gardening techniques and, in some cases, 
manipulation of the photoperiod. There is no magic button to push or secret 
fertiliser to sue. The secret of potency lies within the embryo. The environment 
can and does affect potency, as it does most aspects of the plant's life. 
However, environmental factors are secondary to the plant's heritage (genetic 
potential). 
Indoors vs. Outdoors
At this point the book divides into separate indoor and outdoor cultivation 
sections, and you may wonder whether it is better to grow the plant indoors or 
outdoors. Each alternative has advantages and disadvantages. It is usually 
better to grow the plants outdoors if possible, because the plants can grow much 
larger and faster than indoors. Indoors presents space and light limitations. It 
is possible to grow a 15-foot bush indoors, but this is unrealistic in most 
home. There simply isn't enough room or light for such a large plant. Outdoor 
gardens return a much higher yield for the effort and expense. most indoor 
gardeners buy soil and may have to buy electric lights. So there is an initial 
investment of anywhere from $10 on up. 
On the other hand, outdoor plants are more likely to be seen. Many gardens get 
ripped off, and busts are a constant threat. Indoor gardens are much less likely 
to be discovered. Gardening indoors allows the grower closer contact with the 
plants. The plants can be grown all year long; it is an easy matter to control 
their growth cycles and flowering. Probably the biggest attraction of indoor 
gardens is that they are beautiful to watch and easy to set up anywhere. 
One popular compromise is to construct a simple greenhouse. Use plastic to 
either enclose part of a porch or to cover a frame built against the house. 
The potency of the plants doesn't depend on whether they are grown indoors or 
outdoors. As long as you grow healthy plants that reach maturity and complete 
their life cycle, the grass can be as good as any you've ever smoked. 
PART 2: INDOOR GARDENING
Chapter Four
INTRODUCTION
Marijuana adapts well to indoor conditions. You can grow it in sunny rooms or 
with artificial light. The factor limiting the rate of growth indoors is often 
the amount of light, since it is less a problem to supply the plants with plenty 
of water, nutrients, and air. 
Natural light is free. If feasible to use, natural light eliminates the most 
expensive components for indoor gardeners: artificial lights and the electricity 
they use. Window light is the easiest way to grow plants for decorative purposes 
or for a small crop. On the other hand, a greenhouse, sunporch, or particularly 
sunny room can support larger plants than most artificial light systems. A sunny 
porch or roof area enclosed in sheet plastic to form a greenhouse is a simple, 
inexpensive way to grow pounds of grass. 
Cannabis grows into a fully formed bush when it receives a minimum of five hours 
of sunlight a day. But you can grow good-sized plants of excellent quality with 
as little as two hours of daily sunlight provided windows are unobstructed by 
buildings or trees and allow full daylight. Windows facing south usually get the 
most light, followed by windows facing east and west (north-facing windows 
seldom get any sun). Use the location with the longest period of sunlight. The 
corner of a room or alcoves with windows facing in two or three directions are 
often very bright. Skylights are another good source of bright, unobstructed 
light. 
Some growers supplement natural light with artificial light from incandescent or 
fluorescent fixtures. This is essential during the winter, when sunlight is 
weaker than the summer, and in spaces where the plants get little direct 
sunlight. Artificial lights can also be used to lengthen the natural photoperiod 
in order to grow plants all year. 
The best time to plant using natural light is in late March or April, when the 
sun's intensity and the number of hours of daylight are increasing. Cleaning 
windows dramatically increases the amount of light, especially in cities where 
grime collects quickly. Paint walls adjacent to windows a flat white or cover 
them and the floor with aluminium foil to reflect light to the plants. Place 
young plants on shelves, blocks, or tables to bring them up to the light. 
Position the plants as close to the windows as possible. Insulate germinating 
plants from freezing winter drafts by stapling clear sheets of polyethylene film 
to the window frame. 
The main problem with marijuana in windows is that it may be seen by unfriendly 
people. This won't be a problem at first, but when the plants grow larger, they 
are easily recognised. You could cover the windows with mesh curtains, rice 
paper, polyethylene plastic or other translucent materials to obscure the 
plants. A strip covering the lower part of the window may be enough to conceal 
the plants from outsiders. 
Most of you will want the garden completely hidden. Some gardeners opt for 
closets, basements, attics - even under loft beds. They cover the windows if the 
garden is visible and grow the plants entirely with artificial light. 
The amount of light you provide is what determine the garden's size - the amount 
of soil, number and eventual size of the plants, and the overall yield. Since 
light is the factor on which you base the planning of your garden, let's begin 
with artificial light. 
{A picture of a self-contained mini-horizontal (150 or 175 watt HID) is
perfect for a personal small garden.}
   
Chapter Five
ARTIFICIAL LIGHT[
5.2 Fixtures
Florescent light is the most effective and efficient source of artificial light 
readily available to the home grower. Florescent lamps are the long tubes 
typical of institutional lighting. They require a fixture which contains the 
lamp sockets and a ballast (transformer) which works on ordinary house current. 
Tubes and their fixtures come in length from four inches to 12 feet. The most 
common and suitable are four- and eight-foot lengths. Smaller tubes emit too 
little light for vigorous growth; longer tubes are unwieldy and hard to find. 
The growing area must be large enough to accommodate one or more of these 
fixtures through a height of at least six feet as the plants grow. Fixtures may 
hold from one to six tubes and may include a reflector, used for directing more 
light to the plants. Some fixtures are built with holes in the reflectors in 
order for heat to escape. They are helpful in areas where heat builds up 
quickly. You can make reflectors with household materials for fixtures not 
equipped with reflectors. Try to get fixtures that have tubes spaced apart 
rather than close together. See 5.5 for further suggestions. 
The tubes and their appropriate fixtures are available at several different 
wattage or outputs. Standard or regular output tubes use about 10 watts for each 
foot of their length - a four-foot tube has about 40 watts and an eight-foot 
tube about 80 watts. 
High Output (HO) tubes use about 50 percent more watts per length than regular 
output tubes and emit about 40 percent more light. An eight-foot (HO) runs on 
112 to 118 watts. Very High Output (VHO) or Super High Output (SHO) tubes emit 
about two-and-a-half times the light and use nearly three times the electricity 
(212 to 218 watts per eight-foot tube). 
The amount of light you supply and the length of the tube determine the size of 
the garden. Marijuana will grow with as little as 10 watts per square foot of 
growing area, but the more light you give the plants, the faster and larger they 
will grow. We recommend at least 20 watts per square foot. The minimum-size 
garden contains a four-foot fixture with two 40-watt tubes, which use a total of 
80 watts. Dividing total watts by 20 (watts per square foot) gives 80w divided 
by 20w/sq. ft=four sq.ft. (an area one by four feet). A four-tube (80 watts 
each) eight-foot fixture would give: 320w divided by 20w/sq. ft. = 16 sq. ft. or 
an area the length of the tube and about two feet wide. 
VHO and HO tubes in practice don't illuminate as wide an area when the plants 
are young, because the light source is one or two tubes rather than a bank. Once 
the plants are growing well and the light system is raised higher, they will 
illuminate a wider area. Figure about 25 w/(ft*ft) for HO and 35 w/(ft*ft (or 
foot squared)) for VHO to determine garden size. A two-tube, eight-foot VHO 
fixture will light an area the length of the tube and one-and-a-half feet wide. 
The more light you give the plants, the faster they will grow. Near 50w/sq. ft. 
a point of diminishing returns is reached, and the yield of the garden is then 
limited by the space the plants have to grow. For maximum use of electricity and 
space, about 40w/sq. ft. is the highest advisable. Under this much light the 
growth rate is incredible. More than one grower has said they can hear the 
plants growing - the leaves rustle as growth changes their position. In our 
experience, standard-output tubes can work as well as or better than VHO's if 
four or more eight-food tubes are used in the garden. 
The yield of the garden is difficult to compute because of all the variable that 
determine growth rate. A conservative estimate for a well-run garden is one 
ounce of grass (pure smoking material) per square foot of garden every six 
months. 
In commercial grass, the seeds and stems actually make up more of the bulk 
weight than the useable marijuana. 
The grass will be of several grades depending on when and what plant part you 
harvest. The rough breakdown might be 1/3 equal to Mexican regular, 1/3 
considered real good smoke, and the rest prime quality. With good technique, the 
overall yield and the yield of prime quality can be increased several fold. 
5.3 Sources
When sunlight is refracted by raindrops, the light is separated according to 
wavelengths with the characteristic colours forming a rainbow. Similarly, the 
white light of electric lights consists of all the colours of the visible 
spectrum. Electric lights differ in the amount of light they generate in each of 
the colour bands. This gives them their characteristic colour tone or degree of 
whiteness. 
Plants appear green because they absorb more light near the ends of the visible 
spectrum (red and blue) and reflect and transmit more light in the middle of the 
spectrum (green and yellow). The light energy absorbed is used to fuel 
photosynthesis. Almost any electric light will produce some growth, but for 
normal development the plants require a combination of red and blue light. 
Sunlight has such a high intensity that it can saturate the plants in the blue 
and red bands, though most of the sun's energy is in the middle of the spectrum. 
Artificial lights operate at lower intensities; so the best lights for plant 
growth emit much of their light in the blue and red bands. 
Fluorescent Tubes
Several lighting manufacturers make tubes (gro-tubes) the produce much of their 
light in the critical red and blue bans. (Plant-gro (GE), Gro-Lux (Sylvania), 
Agro-Lite (Westinghouse), and gro-lum (Norelco) are examples, and they look 
purple or pink. Vita-lite and Optima (Duro-test) produce a white light with a 
natural spectrum very similar to daylight. Duro-test blubs are more expensive 
than other tubes but they last twice as long. {See spectrum for "The action 
spectra of chlorosynthesis and photosynthesis compared to that of human vision. 
Adapted from IES Lighting Handbook237"} 
Theoretically, these tubes should work better for growing plants than standard 
lighting tubes. However, some standard or regular fluorescent tubes used for 
lighting actually work better for growing plants than more expensive 
natural-spectrum tubes and gro-tubes specifically manufactured for plant growth. 
The reason is that regular fluorescent produce more light (lumens), and overall 
lumen output is more important for growth rate than a specific light spectrum. 
To compensate for their spectrums, use them in combinations of one "blue" 
fluorescent to each one or two "red" fluorescent (Box B). 
Manufacturers use standardised names such as Daylight and Sofwhite to designate 
a tube that has a certain degree of whiteness. Each name corresponds to a tube 
that emits light in a particular combination of colour bands. For example, Cool 
White emits more blue light than other colours and appears blue-white. By 
combining tubes that emit more blue light with tubes that emit more red light, 
the tubes complement each other and produce a more natural spectrum for healthy 
plant growth. More "red light" than "blue light" sources are needed to foster 
healthy growth, so use two red tubes to each blue tube. 
The best combinations are either Warm White or Soft White (red) tubes used with 
either Cool White or Daylight (blue) tubes. These four tube types are common, 
much cheaper, and when used in combination, will give you a better return than 
any of the more expensive gro-tubes or natural-spectrum tubes. Any hardware 
store carries these common lighting tubes, and the cost may be less than a 
dollar each. 
Do not use tubes with "deluxe" in their designation. They have a more natural 
spectrum but emit considerably less light. Preferably, buy "Cool White" since it 
emits 50 percent more light than "Cool White Deluxe." 
Incandescents and Flood Lights
The common screw-in incandescent bulb produces light mainly in the longer 
wavelengths: far-red, red, orange, and yellow. Higher-wattage bulbs produce a 
broader spectrum of light than lower-wattage bulbs. Incandescents can be used 
alone to grow marijuana, but the plants will grow slowly and look scraggly and 
yellow. Incandescents combined with fluorescent work well, but fluorescent are a 
better source of red light. Fluorescent tubes generate slightly less heat per 
watt. With incandescents, heat is concentrated in the small bulb area, rather 
than the length of the tube, and can burn the plants. In addition, incandescents 
have less than one-third the efficiency of fluorescent in terms of electricity 
used. If you decide to use incandescents in combination with fluorescent, use 
two times the wattage of incandescents to blue source fluorescent, that is, two 
40-watt Daylight tubes to about three 60-watt incandescents, evenly spacing the 
red and blu sources. 
The common floodlight has a spectrum similar to but somewhat broader than 
incandescents. Because they cast their light in one direction and operate at 
higher intensities, these lights work better than incandescents, both as a 
single source and to supplement natural or fluorescent light. {Figure 33. 
Supplement natural light with floodlights. Use foil curtains for reflectors.} 
The best application for floodlights and incandescents is to supplement natural 
and fluorescent light, especially when the plants get larger and during 
flowering. Incandescents and floodlights require no special fixtures, although 
reflectors increase the amount of light the plants receive. These lights are 
easy to hang or place around the sides of any light system, and their strong red 
band promotes more growth and good flower development. Some of their energy is 
in the far-red band. Most purple gro-tubes and white fluorescent are deficient 
in this band, and addition of a few incandescents make them more effective. 
Agro-lite and W/S Gro-Lux emit adequate far-red light and need no addition of 
incandescents. 
Several companies make screw-in spotlights specifically for plant growth. Two 
brand names are Duro-Test and Gro n'Sho. Although they are an improvement over 
incandescents as a single source, these lights don't perform nearly as well as 
fluorescent. A 150-watt bulb would grow one plant perhaps four feet tall. Two 
eight-foot fluorescent tubes (160 watts) will easily grow eight six-foot plants. 
For supplemental lighting, the incandescents and floodlight work as well and are 
cheaper. 
HID Lamps. Metal Halide (MH) and Sodium-Vapour Lamps (HPS)
HID's (High-Intensity-Discharge) are the lamps of choice for serious indoor 
gardeners. HID lamps commonly illuminate streets, parking lots, and sports 
stadiums, and they emit very intense light and produce more light, more 
efficiently than fluorescent. All HID's require specific ballasts and fixtures 
to operate, so purchase complete systems (fixture, ballast, reflector) along 
with the lamp. High Times and Sinsemilla Tips magazines (p. 332) feature 
numerous ads by retailers of horticultural HID systems. Contact the advertisers, 
and they'll send you brochures with enough information to make an informed 
choice. 
Ordinary metal-halides (MH's and HP's) may emit dangerous UV and particle 
radiation of the bulb envelop breaks, cracks, or develops a small hole. Broken 
MH bulbs may continue to operate apparently normally, and exposure may cause 
serious eye or skin injury. Make sure to purchase MH bulbs designed with a 
safety feature (such as GE Sat-T-Gard or Sylvania Safeline) that causes the bulb 
to burn out immediately if the outer envelope ruptures. OR purchase fixtures 
that shield the bulb in protective tempered glass. 
HID's come in many sizes, but generally, use only 400 and 1,000 watt sized 
lamps. The largest size (1,500 watts) is not recommended because of its 
relatively short bulb life. Sizes less than 400 watts do not return as much 
marijuana considering set-up costs and ease of operation. The only exceptions 
are certain "self-contained" mini-units of 150 and 175 watts (see 4.1). These 
mini-self-contained units have a horizontal fixture and built-in ballast, which 
is easy to set up. The horizontal fixture directs up to 45 percent more light to 
the plants than conventional, vertically positioned lamps with reflectors. The 
intense light encourages excellent growth and bud formation with modest 
electrical consumption. They are the best overall light system for small, 
personal gardens such as closet set-ups. 
Position 400 watt HID lamps 18 to 30 inches above plant tops, and 1,000 watt 
lamps 30 to 42 inches above the tops. During flowering, flowers may "run" rather 
than form in compact buds if lamps are positioned too close to the plant tops, 
particularly when using HPS's. 
Heat is the main problem with HID's, and the room must be well-ventilated. Use 
exhaust fans to draw heat out of the room. The fan doesn't need to be large, 
just active enough to create a strong, ventilating draft. 
Light Balancers
Sophisticated gardeners use light balancers which employ a small motor to move 
reflectors and HID lamps held on tracks or mechanical arms slowly across a 
garden in either a linear or circular pattern {(see p. 88 Figure 38b)}. Light 
balances save considerable power and bulb costs because they dramatically 
increase the effectively illuminated garden size, while using less the 24 watts 
per balancer. With the lights moving on a balancer, all of the garden becomes 
equally illuminated for modest running costs. Instead of adding another 1,000 
watt HID, a light balancer increases the garden size without measurably 
increasing power consumption, an important consideration when electricity 
consumption or costs are of concern. 
With multi-bulb HID gardens, use one MH to each HPS lamp on a light balancer, 
and hang the lamps about one foot closer to the plant tops than usual. MH's 
favour blue light, and HPS's produce more orange-red light. By combining the 
two, the spectrum is more balanced, and you'll get a better return of 
well-formed buds. 
Low Cost HID Systems
By far, the most efficient and effective set-up for a modest artificial light 
garden is to use fluorescent lamps set on a long photoperiod for germination, 
growing seedlings or to raise clones; use another room,, or part of the room 
separated by a light-tight curtain or barrier, for flowering with (HPS) lamps in 
horizontal reflectors kept on a short photoperiod to induce and promote 
flowering. 
For example, separate and average sized room into two growing areas by hanging 
an opaque curtain to block light between the two sections. In the smaller area, 
grow seedling or clones (see 18.5) for two to six weeks under fluorescent set on 
a constant light. In the larger section, keep HPS lamp(s) on a 12-hour light 
cycle for flowering. Move larger seedlings under the HPS lamp(s) for about 9 to 
15 weeks to initiate and complete flowering. Meanwhile, start more seedling 
under fluorescent. It's easy to maintain both sections of the room be constantly 
replenishing either area with new plants. This setup is very productive for a 
modest investment in both costs and labour - no time or costly light and 
electricity is wasted on empty space, and you'll find yourself continuously 
harvesting mature buds. 
{A no frills setup with an HID.  Notice that the ballast is insulated from
the floor with pieces of wood; the fixture is supported by rope and not the
electric cord; plastic protects the floor; there is a timer, a reflector, and
fan.}
{Figure 34 and 35 for light-output from two and four 40 watt white
fluorescent and comparing effectiveness in footcandles.}
Using this setup, the initial long photoperiod and small area necessary for 
seedlings or clones is illuminated cheaply by fluorescent. Seedlings grow, and 
cuttings root, better under fluorescent than HPS's. The larger, more costly 
flowering section is kept under a short photoperiod of 12 hours of daily light 
and the strong red light is necessary for good flowering. 
For example, the whole operation could draw less then 650 watts: 160 watts by 
four, four-foot fluorescent set on constant light to start the seedlings; one 
400 watt HPS set on 12 hours daily light for flowering; two timers and a venting 
fan for automating the lights and controlling heat. It's possible to harvest 
four to six, fully mature crops each year, or continuously harvest. (See Mel 
Frank's new Marijuana Grower's Insider Guide by RED EYE PRESS for much more 
information on efficient, low cost, indoor systems and greenhouse gardening.) 
5.4 Setting up the Garden
Under artificial light, marijuana grows from three to sic feet in three months, 
so the height of the light must be easy to adjust. Fixtures can be hung from the 
ceiling, shelves, walls, or from a simple frame constructed for the purpose. If 
you are hanging the lights from the walls or ceiling, screw hooks directly into 
a stud. Studs are located in every room corner and are spaced 16, 18 or 24 
inches apart. Light can be supported from lathing using wingbolts, but plaster 
is too weak to hold a fixture unless a wooden strip held by several wingbolts is 
attached to the walls or ceiling first to distribute the pressure. Then hang the 
fixture from a hook in the strip. Closets have hooks and shelves or clothes 
rungs that are usually sturdy enough to support the fixture. People have gardens 
under loft beds. 
Chains are the easiest means of raising and lowering fixtures. Two chains can be 
suspended from a solid support from above, and attached to an "S" hook at each 
end of the fixture. Raise the fixture by inching the hooks to higher links on 
the chain. Or tie rope to the fixture, pass through an eye hook or pulley in the 
ceiling or frame, and tie-off at a hook or boat cleat anchored in the wall or 
frame. 
You can also hang the lights permanently and lower plants on a shelf or plywood. 
The shelf could be suspended or lowered by supporting the shelf with 
progressively smaller block. This arrangement is often used in "growing 
factories" where plants are rotated to larger gardens and grow for only a few 
weeks in each space. One garden may have fluorescent for starting plants and 
another garden for maturing plants under HID's. With HID's and skylights, 
lowering the plants may be your best option. Use lightweight soil components or 
hydroponics rather than heavier soil, and the operation is easier. 
If you plan to use six or more fluorescent, remove end sockets and ballasts from 
fixtures. Mount end sockets and tubes on a frame of one-by-twos or plywood. 
Space sockets so tubes cover the garden evenly (see Figure 37 and 38). This 
arrangement illuminates the garden more evenly and drastically reduces the 
suspended weight since ballasts make up most of a fixture's weight. Keep 
ballasts off floors and away from water. Mount the ballasts on a nearby wall or 
on a wooden box. Wet ballasts could actually explode, and at best, are 
electrically dangerous when wet. 
Always buy fixtures with reflectors. For HID's, companies make their own 
reflectors, but the best reflectors are for horizontally positioned lights no 
matter which company. Horizontal reflectors focus much more useable light than 
either parabolic or cone reflectors. HPS's can work in any position, but MH 
lamps are made to work in either a horizontal or vertical position, and you must 
buy bulbs that correspond with the fixtures. 
For fluorescents, you can make an overhead reflector from the cardboard cartons 
in which tubes and fixtures are packaged. Cut off the end flaps and form the 
cardboard into a "U". Face inner side with aluminium foil or paint them white. 
Leave enough space so the foil or cardboard does not contact end sockets. Staple 
or tape the reflector behind the tubes to the fixture or from to reflect light 
toward the plants. 
Surround all garden with reflective surfaces, but not so tightly that air can't 
freely circulate. Even in window gardens, reflective sheets set adjacent to the 
plants make a marked difference in growth. When artificial lights are high, 
reflectors from the floor on up keep lower branches actively growing. Mylar, 
with its mirror-finish, is popular for facing walls. A flat white paint (super 
or decorator white) reflects better than glossy white or aluminium foil. Flat 
white has about three percent more reflecting capacity than aluminium foil, and 
reflects light more uniformly. The difference is slight, so use whatever means 
is most convenient. Paint walls that border the garden a flat white or cover 
them with aluminium, mylar, or white plasterboard. {Figure 36. Reflectors can be 
made from sturdy paper faced with aluminium foil. Make them with staples, tape, 
or tacks. Figure 37.} 
Natural-light gardens also benefit from reflectors. Make them out of cardboard 
painted white or faced with aluminium foil. Once the plants are past the 
seedling stage, surround them with reflectors; otherwise only one side of the 
plants will be fully illuminated. 
Covering the floor with a plastic dropcloth (about $1 at any hardware store) 
will protect your flor and your neighbour's ceiling from possible water damage. 
Marijuana grows well in a dry atmosphere, but heated or air-conditioned homes 
are sometimes too dry during germination and early growth. Enclosing the garden 
in reflectors will contain some of the moisture and insure a healthy humidity. 
White sheet plastic is available to enclose open gardens. Do not completely 
enclose the garden. Leave some open spaces at the bottom, top and ends of the 
garden to allow air to circulate. Air circulation will become more important as 
the plants grow larger. 
Don't rely on training your pets to stay out of the garden. The garden will 
attract them, and they can easily destroy young plants by chewing on leaves and 
stems. Soil is more natural to their instincts than the sidewalk or kitty 
litter. Protect the garden from pets and toddlers; surround it with white 
plastic or chicken wire. Large plants are more sturdy and animals can do them 
little harm. The jungle ambience and an occasional leaf are irresistible to most 
cats, and they'll spend hours in the garden. 
5.5 Electricity
For most growers, the amount of electricity used is of little concern. A 
four-tube, regular-output, eight-foot fixture draws about 320 watts per hour or 
about the same as a colour TV. The cost increase to your electric bill will be 
about two to six dollars a month, depending on local rates. 
Farmers who devote entire basements or attics to their gardens are sometime 
restricted by the amount of current they can draw. Older homes or apartments may 
have only one 15-ampere circuit but more often have two, for 30 amperes total. 
Newer homes have either 60 or 100 amperes available through four to six 
circuits. One 15-ampere circuit can safely accommodate three, two-tube VHO 
fixtures or six tubes for 1,290 watts, or 16 regular-output, eight-foot tubes 
for about 1,280 watts total. This allows for a 20 percent safety margin of 
circuit capacity, which is necessary considering heat loss, starting voltages, 
etc. 
In kitchen and basements the circuits may be rated higher, at either 20 or 30 
amperes. You can find out the amperage of the circuit by looking at the fuse 
rating on the face of the fuse. Determine what room or rooms each circuit is 
feeding by removing the fuse and seeing which outlets are not working. The 
wattage capacity of any circuit is found by multiplying volts time amps. 
Standard United States voltage is 110 to 120 volts. 
Fluorescent light fixtures are sometimes sold unwired or without a line cord, 
and the job is left to you. Follow the diagram on the ballast which shows the 
wires marked by their colour. Simply attach the wires to the sockets as 
diagrammed. New sockets have small holes which automatically make contact when 
the bare end of the wire is pushed into them. Older fixtures have sockets with 
conventional screw terminals. 
Indoor gardens may have aluminium foil, chains, reflectors, and wet floors, all 
of which are good electrical conductors. Coupled with hanging lights, these 
conditions could lead to dangerous electrical shocks. Never touch a reflector, 
fixture, or ballast while watering or standing on a damp floor. Eliminate the 
chance of serious shocks altogether by turning off the lights whenever you work 
in the garden. An HID ballast on a damp floor is very dangerous. Raise HID 
ballasts on wood blocks off the floor. 
Reduce the risk of dangerous shocks by using fixtures grounded to the power 
source. A fixture with a three-pronged plug connected to a three-wire outlet is 
grounded in a properly wired house. You can also ground a fixture by connecting 
a #12 or #14 gauge wire to any bare metal screw (not an electric terminal) on 
the fixture housing to the screw that holds the cover plate on the electrical 
outlet your using. 
{With two prong outlets, connect an adaptor plug with a terminal (top left)
or third wire (top right) from the plug to the screw that holds the cover
plate.  This converts two-wire outlets to three wire grounded systems when a
three-wire electric cord is used, an important electrical safeguard which
grounds the light system.}
Chapter Six
SOIL AND CONTAINERS FOR IT
6.2 Pots and Other Containers
In its natural state, marijuana may grow an extensive root system - a fibrous 
network of fine, lateral roots that branch off a main, carrot-shaped tap root. 
In dry areas, the tap root can grow more than six feet deep in its search for 
water. In moist areas with fertile soil (such as in potting mixtures), the 
lateral roots are able to supply water and nutritive needs and the tap root 
remains small, often only three or four inches long on a seven-foot-tall mature 
plant. 
The purpose of the growing medium is to provide adequate water and nutrients in 
addition to anchoring the roots, which hold the plant upright. By watering and 
fertilising as needed, you could grow a six-foot plant in a four-inch ((Pots are 
measured by diameter across the top.)) pot or in a three-foot layer of soil over 
your whole garden; but neither of these extreme procedures is very practical. 
Most growers use containers that will hold between two and five gallons of soil. 
These are a good compromise in terms of weight, space, cost, and labour. They 
can be moved easily and hold an adequate reservoir of water and nutrients to 
support a large mature plant. 
Some growers use a single large box or several long troughs that hold a six- to 
12-inch layer of soil. These have the advantage of minimal restriction of roots 
and less frequent waterings, but they require more soil and make rotating or 
moving the plants impractical. 
Determine the right size pot to use in your garden by the amount of light per 
square foot. For a moderately lighted garden (15 to 25 watts per square foot and 
most window gardens), use one- to three-gallon containers. For gardens with more 
light energy - over 25 watts per square foot or one-half day or more of sunlight 
- use three- to eight-gallon containers. The smallest pot we recommend for a 
full-grown plant is eight inches or one gallon. This is also a good size for 
starting plants to be transplanted after two months. 
Practically any container that can withstand repeated waterings and has a top at 
least as wide as its base will do. Each pot must have several holes in the 
bottom to assure drainage. Growers use flower pots, institutional-sized cans and 
plastic buckets, baskets and small trash cans, milk crates and wooden boxes. 
Plastic trash bags are sometimes used when other large containers can't be 
found. They must be handled carefully, since shifting the soil damages the 
fragile lateral roots. They are also more difficult to work with when 
transplanting. However, a roll of trash bags is an available and inexpensive 
substitute for other large containers. Plastic bags should be double or triple 
bagged. Small holes should be punched in the bottom to drain excess water. Use 
masking tape to patch any unwanted tears. The capacity of the bag should be no 
more than twice as many gallons as the amount of soil used. For example, with 
four gallons of soil, the bag should be of a five-gallon, but not more than 
eight-gallon size. Otherwise, it will not form a cylinder, and the bag will 
remain a shapeless mass. 
Use as many pots as can fit in the lighted area to make the most efficient use 
of space. Many growers prefer to start the plants in smaller pots, transplanting 
into larger pots when the plants are larger. There are definite advantages to 
this method in terms of the yield in the garden, given its space and light 
energy. Seedlings and small plants take up much les space than they will at 
maturity, so they can be placed closer together. As the plants grow and begin to 
crowd each other, remove the less vigorous (to smoke, of course) and transplant 
the rest into larger pots. Start plants which will be transplanted later in 
four- to eight-inch flower pots, or one-quart to one-gallon tin cans or milk 
containers. Peat pots or planting pots are made of compressed plant fibre for 
the purpose of starting young plants. They are available at garden shops and 
come in several sizes. Use at least a four-inch pot so that the roots are not 
restricted in early growth. Peat pots are supposed to break down in the soil, 
but marijuana's delicate lateral roots may not be able to penetrate unless you 
score or break away the sides while transplanting. Wax paper cup (six to eight 
ounces), filled with a soil mixture, work as well as peat pots and are cheaper. 
	BOX C
	Finding Large Containers

		Use your ingenuity in finding large containers.  Large clay
                flower pots do not work any better than the large metal and
                plastic containers discarded by restaurants and food stores.
                Various milk containers are good starting pots.  Many garden
                shops sell used pots for a few cents each.  Wholesalers sell
                plastic pots by the carton at a discount.  Large plastic pots
                and pails can sometimes be picked up inexpensively at flea
                markets or variety stores.  Any vessel that holds an adequate
                amount of soil and does not disintegrate from repeated
                waterings is a satisfactory container.
6.3 Properties of Soil
The soil or growing medium serves as a source and reservoir for water, air, and 
nutrients, and to anchor the roots. Since marijuana grows extremely fast, it has 
higher water and nutritive needs than most plants grown indoors. The success of 
your garden depends on supplying the plant with a medium that meets its needs 
without creating toxic conditions in the process. 
There is no such thing as the perfect soil for Cannabis. Each variety can grow 
within a range of soil conditions. For healthy, full, growth, marijuana prefers 
a medium with good drainage, high in available nutrients, and near a neutral pH 
(7.0). These conditions result from a complex set of physical, chemical and 
biological factors. We will refer to them simply as: (1) texture; (2) nutrients; 
(3) pH. 
Most indoor growers prepare the growing medium using commercial potting mixes. 
These mixes are usually sterilised or pasteurised and have good general soil 
properties. Since they seldom list the contents, nutrients, or pH, do some 
simple test of your basic soil whether you buy or dig for it. Then you can 
adjust the soil to meet the basic requirements of the plant. 
Texture
The texture of the medium determines its water-holding and draining properties. 
Marijuana must have a well-drained medium for healthy growth. Soils that hold 
too much water or hold it unevenly can drown the roots, leading to poor growth 
or death of the plant. In a well-drained soil the roots are in contact with air 
as well as water. Soils that have too much clay, or are overly rich in compost 
or other organic matter, tend to hold too much water and not enough air. This 
condition worsens in time. This is especially true of the soil in pots. 
You can determine the texture of your soil from its appearance and feel. Dry 
soil should never cake or form crusts. Dry or slightly moist soil that feels 
light-weight, airy, or spongy when squeezed, and has a lot of fibrous material, 
will hold a lot of water. Mix it with materials which decrease its water-holding 
capacity, such as sand, perlite, or even kitty litter. 
Wet soil should remain spongy or loose and never sticky. A wetted ball of soil 
should crumble or separate easily when poked. 
Soil that feels heavy and looks dense with fine particulate matter, or is sandy 
or gritty, will benefit by being loosened and lightened with fibrous materials 
such as vermiculite, Jiffy Mix, or sometimes sphagnum moss. 
Soil Conditioners to Improve Texture
Perlite (expanded sand or volcanic glass) is a practically weightless 
horticultural substitute for sand. Sand and perlite contribute no nutrients of 
their own and are near neutral in pH. They hold water, air, and nutrients from 
the medium on their irregular surfaces and are particularly good at aerating the 
soil. 
Vermiculture (a micaceous material) and sphagnum moss contribute small amounts 
of their own nutrients and are near neutral in pH. They hold water, air, and 
nutrients in their fibre and improve the texture of sandy or fast-draining 
soils. Jiffy Mix, Ortho Mix, or similar mixes are made of ground vermiculite and 
sphagnum moss, and are fortified with a small amount of all the necessary 
nutrients. They are available at neutral pH, are good soil conditioners, and are 
also useful for germinating seeds. 
Sphagnum and Peat Moss (certain fibrous plant matter) are sometimes used by 
growers to improve water holding and texture. Both work well in small amounts 
(10 to 15 percent of soil mixture). In excess, they tend to make the medium too 
acidic after a few months of watering. Use vermiculite or Jiffy Mix in 
preference to sphagnum or peat moss. 
Nutrients
Nutrients are essential minerals necessary for plant growth. The major nutrients 
are nitrogen (N), phosphorus (P), and potassium (K), which correspond to the 
three numbers, in that order, the appear on fertiliser and manure packages, and 
that give the percentage of each nutrient in the mix (see section 9). 
Marijuana prefers a medium that is high in nitrogen, and mid-range in phosphorus 
and potassium. Generally, the darker the soil, the more available nutrients it 
contains. Commercial soils usually contain a good balance of all nutrients and 
will support healthy growth for a month or two, even in smaller (one gallon) 
containers. Many growers prefer to enrich their soil by adding sterilised 
manures, composts, or humus. All of these provide a good balance of the three 
major nutrients. They also retain water in their fibre. In excess they cause 
drainage problems, make the medium too acidic, and attract insects and other 
pests. A good mixture is one part compost or manure to five to eight parts of 
soil medium. In large pots (four or five gallons), these mixtures might provide 
all the nutrients the plant will ever need. {Table 13.} 
The many prepared organic and chemical fertilisers that can be mixed with the 
soil vary considerably in available nutrients and concentrations. Used in small 
amounts, they do not appreciably effect the soil texture. Many prepared 
fertilisers are deficient in one or more of the major nutrients (see Table 14). 
Mix them together so there is some of each nutrient, or use them with manures, 
which are complete (contain some of all three major nutrients). When adding 
fertilisers, remember that organic materials break down at different rates. It 
is better to use combinations which complement each other, such as poultry 
manure and cow manure, than to use either fertiliser alone. (See Table 22 in 
section 13 for a complete list of organic fertilisers. 
Table 14 - Prepared Organic Fertilisers

Type of             Percentage by weight of    Availability to
fertiliser          N        P2O5     K20      Plant
-----------------------------------------------------------------
Blood meal          13        0        0       Rapid/medium
Bone meal            0.5     15        0       Medium/slow
Blood/bone meal      6        7        0       Medium/slow
Cottonseed meal      6        2        1       Slow/medium
Fish meal            8        2        0       Slow/medium
Hoof and bone meal  10        2        0       Slow
Rock phosphate       6       24        0       Slow
Wood ash             0        1.5    3-7       Rapid
Greensand            0        0      2-8       Medium/slow
Chemical fertilisers are made in about every conceivable combination and 
concentration. Pick one that is complete and where the first number (N) is at 
least equal if not higher than both P and K. For example, rose foods may be 
12-12-12 or 20-20-20, and work very well for marijuana. Others are: Vigoro 
18-4-5 and Ortho 12-6-6. The higher the number, the more concentrated the mix 
is, and consequently, the more nutrients are available. 
Don't use fertilisers which come in pellets or capsules, or that are labelled 
"timed" or "slow release." They do not work as well indoors as do standard 
organic and chemical fertilisers. Chemical fertilisers seldom list the amount to 
mix per pot. You can get some idea by the instructions for application per 
square foot. Use that amount of each one-half cubic foot of soil mixture. 
Many growers add no nutrients at this time but rely on watering with soluble 
fertilisers when they water. These fertilisers and their application are 
discussed in section 9. 
pH
The pH is a convenient measure of the acidity or alkalinity of the soil medium. 
It is another way of expressing whether the soil is bitter (alkaline) or sour 
(acid). The pH is measured on a scale of 0 to 14, with 7.0 assigned neutral; 
below 7.0 is acid and above is alkaline. 
You can think of the pH as a measure of the overall chemical charge of the 
medium. It affects whether nutrients dissolve to forms available to the plant or 
to forms the plant can't absorb, remaining locked in the soil medium. 
Marijuana responds best to a neutral (7.0 pH) medium, although in a fertile, 
well-drained soil, it will grow well in a range of 6.0 to 8.5. The simplest way 
to check the pH is with a soil-test kit from a garden shop or nursery. Test kits 
are chemicals or treated papers - for example, litmus papers or Nitrazine tape - 
that change colour when mixed with a wet soil sample. The colour is then matched 
to a colour chart listing the corresponding pH. Nitrazine tape is available, 
inexpensively, in drug stores. Some meters measure pH, but these are expensive. 
Agricultural agents, agricultural schools, and local offices of Cooperative 
Extension will test a soil sample for pH and nutrient content. Occasionally, a 
garden-shop person will check pH for you or will know the pH of the soils they 
sell. 
Highly alkaline soils are characteristically poor soils that form cakes, crusts, 
and hardpan. Soil manufacturers don't use them, nor should they be dug for 
indoor gardens. Alkaline soils are treated with sulphur compounds (e.g., iron 
sulphate) to lower the pH. 
We have never seen commercial soils that were too alkaline for healthy growth, 
but they are sometimes too acidic. The pH of acid soil is raised by adding lime 
(calcium-containing) compounds. Liming compounds come in many forms and grades. 
Some are hydrated lime, limestone, marl, or oyster shells, graded by their 
particle size or fineness. Use the finest grade available, since it will have 
more of a neutralising potential than a coarse grade. You need to use less and 
are more interested in immediate results than long-term soil improvement. For 
indoor gardens, use hydrated lime (available in any hardware store) or wood 
ashes to raise the pH. Hydrated lime is rated over 90 percent for its 
neutralising potential. Wood ashes will neutralise soil acids roughly one-half 
as well as hydrated lime. However, they also contain some nutrients (potassium, 
phosphorus, magnesium, and micronutrients) and are handy and free. 
There is no exact formula we can give you for raising the pH. The pH does not 
have to be exact; it's and approximation. At low pH it takes less lime to raise 
the pH one point than it does when the pH is near neutral. Sandy soils need less 
lime to raise the pH one point than soils high in clay or organic matter. In 
general, add three cups of hydrated lime or six cups of fine wood ash to every 
bag (50 pounds or a cubic foot) of soil to raise the pH one point. For soils 
that test slightly acid (about 6.5), add two cups of lime or four cups of wood 
ash. 
Soil that tested below 6.0 should be retested in about two weeks, after 
thoroughly mixing and wetting the soil. Repeat the application until the pH is 
in an acceptable range. Check the pH of plain water to see if it is influencing 
the tests. Distilled water is neutral, but tap water sometimes has minerals that 
can change the pH. Hard water is alkaline. Sulphurous water and highly 
chlorinated water are acidic. 
If you have already added lime to a soil that now tests from 6.5 to 7.0, don't 
add more lime trying to reach exactly 7.0. Too much lime will interfere with 
nutrient uptake, notably of potassium, phosphorus, and magnesium. 
General Soil Characteristics
The texture, pH, and available nutrients of the soil are all related. The most 
important single factor is texture (good drainage). When soil drains poorly, it 
creates anaerobic (without air) pockets in the soil. Bacteria or microbes that 
live without air will begin to multiply and displace beneficial microbes that 
need air to survive. The anaerobic microbes break down organic matter to a finer 
consistency, and release CO2 and organic acids to the medium. Drainage worsens, 
the acids lower the pH, and nutrients, even though present, become unavailable 
to the plant. 
The result can be a four-month-old marijuana plant that is only three inches 
tall, especially if you use high concentrations of manures and composts, peat 
and sphagnum moss. If your soil lists manures or composts as additives, add no 
more than 10 percent of these on your own.f 
Drainage problems sometimes develop after several months of healthy growth. It 
is a good idea to add about 20 percent sand or perlite to even a well-drained 
soil. You can never add too much of these; they con only improve drainage. They 
dilute the nutritive value of the soil, but you can always water with soluble 
fertilisers. 
Mixtures using many components in combination seem to work particularly well. 
This may be because, at a micro-level each component presents a slightly 
different set of physical, chemical and biological factors. What the plant can't 
take up at one point may be readily available at another. 
6.4 Preparing Commercial Soils and Mixes
Garden soils (or loams) and potting mixes are actually two different groups of 
products, although they are frequently mislabelled. Some companies sell soil in 
large bags and a potting mixture in smaller bags, while labelling them the same. 
Soils and potting mixtures are usually manufactured locally, since 
transportation costs are prohibitive; so they differ in each area. 
Texture and Nutrients
Soils and loams are usually topsoil blended with humus or compost for use as a 
top dressing in gardens, for planting large outdoor containers, or for the soil 
part of a potting mixture. They may have a tendency to compact under indoor 
conditions and will benefit from the addition of perlite or vermiculite. Soils 
and loams usually contain a good supply of nutrients and may support a 
full-grown plant in a large container. Commercial soils that are heavy generally 
work better than lightweight soils. Heavy soils usually contain topsoil, in 
which marijuana grows very well. Lightness indicates more fibrous content. 
For example of possible soil mixtures, see Box D. pre?
BOX D Examples of Soil Mixtures* 1. 5 parts soil 2. 8 parts soil 2 parts perlite 
3 parts sand 1 part cow manure 1/4 part 10-10-10 chemical fertiliser 3. 5 parts 
soil 4. 4 parts soil 2 parts perlite 1 part sand 2 parts humus 1 part 
vermiculite 1/2 part cottonseed meal 2 parts humus 1/2 part poultry manure 5. 3 
parts soil 6. 6 parts soil 1 part perlite 2 parts perlite 1 part sand 2 parts 
vermiculite 2 parts Jiffy Mix 1/2 part poultry manure 1/2 part blood/bone meal 
1/2 part cow manure 1/2 part wood ash 1 part wood ash *Almost all fertilisers 
are acidic, and need to be neutralised by lime. For the above mixtures, or any 
similar ones, mix in one cup of lime for each five pounds of manure, cottonseed 
meal, or chemical fertiliser in order to adjust the pH. 
Potting mixes are intended to support an average-size house plant in a 
relatively small pot. They are sometimes manufactured entirely from wood and 
bark fibre, composts, and soil conditioners. These mixes are made to hold a lot 
of water and slowly release nutrients over a period of time, which is what most 
house plants require. For marijuana, these mixes seldom contain enough nutrients 
to support healthy growth for more than a couple of months. (Their N is usually 
low, P adequate, and K usually very high.) They work best when sand or perlite 
is added to improve drainage, and fertilisers are added to offset their low 
nutrient content. 
The pH
Most commercial mixes and soils are between 6.0 and 7.0 in pH, a healthy range 
for marijuana. If you buy your soil, it will not be too alkaline for healthy 
growth, but it might be too acidic. You can minimise the chances of getting and 
acid soil by avoiding soils with "peat" or "sphagnum" in their names. Avoid 
soils that are prescribed for acid-loving plants such as African violets or 
azaleas, or for use in terrariums. With common sense, you can buy a soil, add 
two cups of lime to each large bag, and not have to worry about the pH. However, 
the surest procedure is to test the pH yourself. 
Probably the best way to find the right soil for your garden is to ask long-term 
growers. They can relate their past experiences with various mixes and blends. 
Most long-term growers with whom we have talked have tried many of the mixes 
available in their areas. A reliable, enlightened nurseryperson or plant-shop 
operator may also be able to give you some advice. 
6.5 Buying Soil Components
All the materials discussed here are available at farm and garden stores or 
nurseries. Many suburban supermarkets sell large bags of soil and humus. Always 
buy your materials in the largest units possible to reduce the cost. 
Large bags of soil and humus come in either 50-pound bags or one- to 
four-cubic-foot bags. A 50-pound bag fills about six gallons. There are eight 
gallons to a cubic foot. Perlite is sold in four-cubic-foot bags (thirty-two 
gallons). Jiffy Mix and vermiculite are sold in four-cubic-foot bags and in 16 
pound bags (about 18 gallons). Sand, perlite and vermiculite come in coarse, 
medium, and fine grades. All grades work well, but if you have a choice, choose 
coarse. Sand (not beach sand) is an excellent soil conditioner. The only 
disadvantage is its heavy weight. Buy sand from lumber yards or hardware stores 
where it is sold for cement work. It will cost from 1/50 to one-half the cost of 
garden or horticultural sand. Sand from piles at construction sites works very 
well. 
Calculating the Amount of Soil
The maximum amount of soil mixture for any garden can be found by multiplying 
the capacity of the largest pot you plan to use by the number of pots that you 
can fit in the garden. In many cases, the actual amount of the mixture used will 
be somewhat less. Two illustrations follow. 
1. A small garden with a two-tube, eight-foot fixture (160W). Using 20 watts per 
square foot for fast growth gives 160W divided by 20W/sq.ft. + eight sq.ft. The 
largest pot needed for this system is three gallons, but two gallons would work. 
You can fit about 10 three gallon pots in eight square feet; so 3 * 10 + 30 
gallons of soil mixture are needed (see Box E). 
	BOX E
	Examples Showing How Much Soil Material to Buy to Fill
	a Known Number of Unit-Volume Containers

	Example 1.  For a garden eight square feet in size,
	Buy		Component         Which amounts to

	 3 50-lb (6 gal. ea. ) bags of	soil	18 gallons
	 1 cubic foot of	perlite	 8 gallons
	30 lbs of	humus	 3 gallons
	10 lbs of	chicken manure	 2 gallons
			TOTAL	31 gallons

	Example 2.  For a garden 24 square feet in size,
	Buy		Component         Which amounts to

	 4 1-cu. ft. bags of	soil	32 gallons
	 2 1-cu. ft. bags of	perlite	16 gallons
	 1 1-cu. ft. bag of	vermiculite	 8 gallons
	20 pounds of	cow manure	 3 gallons
			cottonseed meal	 2 gallons
			wood ash	 2 gallons
			TOTAL	63 gallons
2. A large garden with two two-tube, eight-foot VHO fixtures (four times 215 
watts or 860 total watts) illuminating a garden three by eight feet, or 24 
square feet. 
860 watts divided by 24 sq. ft. = about 36W/sq. ft. 
The largest pot size for this system is about five gallons. About 16 five-gallon 
containers can fit in 24 square feet; so 16 * 5 + 80 gal. of mixture are needed. 
But you could start many more plants in smaller containers and transplant when 
they are root-bound. You do not use more soil by starting in smaller pots, since 
all soil is reused. In many cases, you actually use much less soil. 
In this system you could start and fit about 40 plants in one-gallon pots in 24 
square feet. When the plants begin to crowd each other, some are harvested, 
making room fir the others, which are transplanted to larger pots. In practice, 
a high-energy system such as this one (36W/sq. ft.) will grow large plants whose 
size is limited mainly by the space available. Twelve large female plants are 
about the most you would want in the system during flowering and for final 
harvest. Sixty gallons of mixture is all that is needed for the seedlings and 
the mature crop. This is one-fourth les than the original estimate of 80 
gallons, and you actually will harvest a lot more grass (see Box E). 
Mixing and Potting
Mix your soil in a large basin, barrel, or bathtub. Individual pots are filled 
with mixtures by using a smaller container to measure out by part or volume. 
Perlite, sand, and dry soil can give off clouds of dust. When mixing large 
amounts of these, wear a breathing mask or handkerchief over your nose and 
mouth. 
To pot any of the mixtures, first cover any large drainage holes with a square 
of window screen or newspaper to prevent the mixture from running out. Place a 
layer of sand, perlite, or gravel about one inch deep to insure drainage. Fill 
the pots with soil mixture to within three-fourths of an inch from the top of 
the pot. If your mixture contains manures or composts, cover the last inch or 
two in each pot with the mixture minus the manure and compost. This will prevent 
flies, gnats, moulds, and other pests from being attracted to the garden. Press 
spongy soils firmly (not tightly) to allow for more soil in each pot; otherwise, 
after a period of watering, the soil will settle and the pot will no longer be 
full. 
Some growers add a few brads or nails to each pot to supply the plant with iron, 
one of the necessary nutrients. Water the pots and allow them to stand for a day 
or two before planting. As the soil becomes evenly moist, beneficial bacteria 
begin to grow and nutrients start to dissolve. {Figure 40.} 
6.6 Digging Soil
Most growers prefer to buy their soil, while some prefer to dig it. Marijuana 
cannot tolerate heavy clays, mucks, or soils that dry to crusts. Choose a soil 
from a healthy garden or field, or from an area that supports a lush growth of 
annual weeds. 
Fields that support a good crop of alfalfa, corn or other grains will support a 
good crop of marijuana. Fields with beets, carrots, and sugar cane indicate a 
well-drained soil, with near neutral pH. Red clover, sweet clover, and bluegrass 
have soil requirements similar to those of marijuana. Garden soils are usually 
fertile and well-drained, but often need lime to counteract soil acidity. 
Take the topsoil layer that starts about two inches below the surface debris. 
Good soil will look dark, feel moist, and small clean and earthy. Use all of the 
topsoil layer that maintains its dark colour and is interlaced with roots. Your 
hands should be able to easily penetrate the underlying topsoil if the soil is 
in good condition. When the soil changes colour, or roots no longer apparent, 
then you are past the fertile topsoil layer. Abundant worm, millipedes, and 
other small lifeforms are a good indication that the soil is healthy. A rich 
layer of topsoil collects by walls, fences, and hedges where leaves and debris 
collect and decay to a rich humus. Sift the soil to remove stones and root 
clods. Also, shake out the root clods, which are rich in nutrients. 
Soil that is dug should be tested the same way as already prescribed. It should 
be adjusted with at least 30 percent sand or perlite (vermiculite for very sandy 
soils), since potting will affect the drainage of even well-drained soils. Never 
use manures or composts that are not completely degraded to a clean-smelling 
humus. 
Soil that is dug must be sterilised to kill weed seeds, insect eggs, and harmful 
moulds and fungi. Some chemical treatments (e.g. formaldehyde) are mixed with 
water and poured over the soil to sterilise it. Soil can be sterilised in a 
pressure cooker at 15 pounds pressure for 15 minutes, or by baking wet soil in a 
large pot at 200 degrees for 30 to 40 minutes. Be advised that baking soil will 
release some formidable odours. 
6.7 Growing Methods
As we said before, there are probably as many growing methods as there are 
marijuana growers. These methods are personal preferences or adaptions to fit 
particular situations; one method is not necessarily better than any other. 
However, the value of a garden is often based on the amount of high-quality 
grass it yields. Since indoor gardens are limited in size, you want the plants 
to quickly fill the garden with lush growth in order to use the garden 
efficiently. Otherwise, for the first couple of months, the lights are shining 
on empty space. 
Secondly, the possession of small quantities of marijuana will probably be 
decriminalised nationally within the next few years. Decriminalisation for 
personal possession will open the way for decriminalisation for cultivation for 
personal possession. But small quantities are more difficult to define for 
cultivation than for simple possession, which is done by weight. Several 
possible ways to limit the amount for cultivation have been raised: by the 
number of plants, by the area cultivated, or by the number of plants at a 
particular stage of development. The outcome may determine whether you try to 
grow the largest plants possible or the most plants possible in a given area. 
There are several ways to increase your garden's yield. 

	1.  Pinch or cut back the growing shoots when the plants are young.
            This forces each plant to develop several strong growing shoots
            and generally yield large robust plants.
	2.  Plant a number of plant in each pot.
	3.  Start many plants in small pots and transplant the best plants to
            larger pots when the plants crowd each other.
	4.  Use different light systems to grow plants at different growth
           stages.
Here are some examples of how to carry out each of these four methods. 
  1. Fill the growing area with large containers (about five gallons each). 
  Start several plants in each pot but thin the seedlings over a period of six 
  weeks to two months, until one plant is left in each pot. During the fourth or 
  fifth week of growth, pinch back the plants to about equal heights. Cut the 
  growing shoot at about the fourth internode. Each plant will develop a sturdy 
  stem which will support four to eight growing stems and will quickly fill any 
  empty space in the garden. The whole garden is the treated like a hedge. After 
  another month or two, you cut back the growing shoots again to have plants of 
  equal heights. Remove the male plants as soon as they begin to release pollen 
  (or before any male flowers open for sinsemilla). This will leave more space 
  and light for the females to develop. By the time females flower, they've been 
  cut back two or three times or more, and form a dense growth of growing shoots 
  that fill the garden with a cubic layer of flowers. Some growers maintain the 
  plants for up to a year before the final harvest. 
{Figure 41.  Plant clipped at fourth internode.}
  2. This method also requires large pots. Instead of thinning the seedlings to 
  leave one per pot, leave at least three. After a few months of growth, remove 
  any plants that lag far behind or any plants that show male flowers. The value 
  of this method is that the odds are at least seven to one that any pot will 
  have at least one female plant. 
  Most of the plants you'll grow will fill out with branches by four months at 
  the latest. Often the branches develop young seedlings. The plants may begin 
  to look like small Christmas trees by the second to third months of growth. 
  Generally, you don't want to have more than three or four plants in a 
  five-gallon container, because growth will be limited by competition for light 
  and space. 
{Figure 42.  Basement growing factory in Atlanta.}
  Some varieties never do fill out. The branches remain small, only two to three 
  inches long, and yield very little grass. We've seen plants like this grown 
  from grass from Vietnam, Thailand, Afghanistan, and Africa. These plants are 
  also quite short, being four to six feet tall fully grown. With varieties like 
  this, it is better not to pinch tops, and to start about six plants per square 
  foot of garden space. At harvest, the garden will be crowded with top stems 
  that are laden with flower clusters. 
  Of course, you don't know what varieties will look like until you've seen them 
  grow. For most varieties, each plant will need at least one square foot or 
  space at maturity. It is much less common to find varieties that naturally 
  grow small or especially thin, and, therefore, are those of which you would 
  want to plant more than a few per large pot. 
  3. Another popular way to grow is to start plants in a large number of small 
  pots. As the plants crowd each other, some are removed and the rest 
  transplanted to larger pots. 
  4. To get the most for your investment requires conservation of light and 
  soil. When the plants are young, a large number fit into a small place. Some 
  growers take advantage of this fact by having several light systems, each with 
  plants at different growth stages. The plants are rotated into larger gardens 
  and pots. This method conserves space, materials, and electricity, and yields 
  a harvest every two months. Using this method, "growing factories" turn out a 
  steady supply of potent grass. {Table 15.} 



Chapter Seven
MAINTAINING THE CORRECT ENVIRONMENT
7.2 Requirements for Germination
Before the seed fell, almost all of its water was sapped to prepare the seed for 
winter. With only the tiny drop that it holds, the embryo lives a life so slow 
as to be outside of time as we know it. Cannabis seeds need only water to 
germinate or sprout. The seeds germinate without light and at temperatures low 
enough to form ice. Higher temperatures hasten germination. Fresh, homegrown 
Oaxacan seeds germinated in three days at 70F and in eight days at 33F. 
Temperatures 70 to 90F are best for germination. 
Fresh, mature seeds have a high rate of germination (about 90 to 100 percent) 
and sprout quickly. Usually sprouts appear three to seven days after planting. 
Older seeds (over a year, depending on storage) have a lower rate of germination 
and respond slower. They may take up to three weeks to sprout. To get an idea of 
what to expect from the seeds follow the procedure in 3.1. 
Seeds that do sprout will grow normally, no matter how old they are or how long 
they take to sprout. From any batch of seeds, most of the ones that sprout will 
do so within two or three days of each other. A few will continue to come up as 
many as six months later, but the garden should consist of plants that are 
basically the same age and size. This makes the garden easier to care for. 
Choosing Seeds
Different varieties grow at different rates and attain different sizes and 
shapes. Under artificial lights, gardens plants from one batch of grass require 
the least attention, because the plants sprout and grow uniformly and can all be 
tended at the same time. When several varieties are grown together, some plants 
are taller than others; you must adjust the height of the plants to keep the 
marijuana equally illuminated. You may also have to water and fertilise the 
plants on an individual basis. Some growers start at different varieties under 
separate light systems. On the other hand, planting several varieties offers you 
a comparison in potency and yield, and a source for hybrids if you want to 
develop seed. The next time you plant you'll know which seeds gave the best 
results and what growing methods will work best for you. {Figure 43. Within each 
seed lies and embryo.} 
There is no strict correlation between the form and height of the plants and 
seed size, colour, or pattern. However, some large-seeded varieties grow too 
tall, with long spaces between leaves. Under artificial lights they yield more 
stems than leaves. If you have a choice between two equally potent grasses, and 
one has particularly large seeds (3/16 to 1/4 inch), choose the smaller-seeded 
variety. 
Sowing
The easiest way to start the plants is to sow the seeds directly into the soil. 
First, wet the soil with a moderate amount of water, enough to wet the soil with 
a moderate amount of water, enough to get the soil evenly moist without water 
running out the bottom. This takes about one-half quart of water for one-gallon 
containers, and about one quart for three-gallon containers. Plant the seeds a 
quarter- to half-inch deep. The germination rate is lower when they are planted 
deeper; and if seeds are planted less then one-quarter inch deep, the sprouts 
may have difficulty anchoring their roots. Plant about six seeds per pot to 
assure some sprouts in each pot. Gently press each seed into the soil. Cover the 
seeds with soil and sprinkle lightly with water. Each day, sprinkle or spray the 
surface with enough water to thoroughly wet the top half-inch of soil, since the 
seed must be kept moist for germination. 
For most people, germinating the seed is easy. Problems with germination come 
from either too much or too little water. If you saturate the pots with water, 
and especially if you continue to saturate the pots after the seeds have 
sprouted, the seedlings may develop stem rot or root problems. When stem rot 
develops, the base turns brown, and the seedlings fall over, ending the garden. 
This can also happen if you keep seedlings in germination boxes or terrariums 
where the humidity is very high. When the humidity is low, the soil surface 
dries out quickly and the seeds won't germinate. Sprouts that may come up 
shrivel and dry at the base of the stem and die. 
The key to germination is to keep the soil surface moist after first having 
moistened the whole pot; then, after the first sprouts have been up for a few 
days, let the surface of the soil dry between waterings. Don't spray the surface 
any more. Water with medium amounts of water when the soil in the top couple of 
inches feels dry. For small pots, water seedlings about twice a week. For larger 
pots, once each week or two may be enough. 
Some growers prefer to plant only seeds they know will sprout, especially when 
planting seeds which have a low viability. Start the seeds in wet towels or a 
glass of water. Add one teaspoon of liquid bleach (a three-percent solution) to 
each cup of water. This will prevent fungus from attacking the seeds, which 
happens when they are soaked for more than three days. Check the seeds each day. 
Plant when the radical or roots begins to come out from the pointed end of the 
seed. Cannabis seed is quite small and has only enough stored food for the 
embryo to anchor its root and raise its cotyledons. The more developed the root 
is when planted, the less energy it has to anchor itself in the soil. The sprout 
may die or growth be delayed until the root is established (transplant shock). 
In Figure 44, the seeds in a circle are all ready to plant. The centre seed will 
not survive transplanting. {Figure 44. Seeds in a circle are ready to plant. 
Centre sprout will not survive planting 
{**Centre sprout too large**}}
Some growers prefer to start the plants in a germination box. This extra hassle 
is not necessary. Transplanting seedlings from one medium to another often 
causes transplant shock. It is best to plant the seeds directly into the soil. 
If you use Soilless mixtures, your seedlings should be started in paper cups, 
peat pots, or other small pots filled with a soil mixture (see "Transplanting" 
in Chapter 8 {8.3}). This procedure is also helpful if you have the difficulty 
starting the plants in large containers. Expandable peat pellets also work very 
well. 
The position of the seed in the soil has a slight effect on germination. The 
root directs its growth in response to gravity, as shown in Figure 45. However, 
germination is a little faster when the seeds are planted with the pointed end 
up. The difference is small, and it's not really necessary to position the seeds 
in the soil. 
If a dry atmosphere presents problems, you can create the moist atmosphere of a 
germination box and still plant directly in the pot. Cover the seeds with 
transparent plastic cups or glasses, or cover the pot with plastic kitchen wrap. 
This creates a greenhouse effect and keeps the soil surface moist without 
watering. Remove all the covers as soon as you see the first sprouts begin to 
appear; the sprouts will die if the cover is left on. {Figure 45. The root 
directs its growth toward gravity. Seeds are germinated between glass and 
cotton, and held vertically. Four seeds to left have pointed and up. Two middle 
seeds are horizontal. Sex seeds on right have pointed end down.} {Figure 46. 
During germination soil can be kept moist by using plastic covers to create a 
greenhouse effect.} 
7.3 Light Cycle and Distance of Lights from Plants
The seed doesn't need light to germinate. The sprout does need light as soon as 
it breaks through the soil. Most growers turn the light on when they sow the 
seeds, though, to warm the soil and encourage germination. Lights may also dray 
the surface of the soil, especially in large pots or with VHO fixtures. If this 
is a problem during germination, leave the lights off until you see the first 
sprout breaking through the soil; or hang the lights about 18 inches above the 
soil, and lower them to six inches as soon as the sprouts appear. 
It is important for normal development that the plants receive a regulated 
day/night cycle. We emphatically recommend that you use an automatic electric 
timer (about $8). A timer makes gardening much easier, since you don't have to 
turn the lights on or off each day. The plants won't suffer from irregular hours 
or your weekend vacations. Set the timer so that the plants get about 16 to 18 
hours of light a day, and leave it on this setting until the plants are well 
grown (three to six months) and you decide to trigger flowering. 
During the seedling and vegetative stages of growth, the plants may be subjected 
to light during their night period. During flowering, however, the night period 
must be completely dark. 
The plants grow more slowly with less than 16 hours of artificial light a day, 
and they may flowers prematurely. Some growers leave the lights on up to 24 
hours. A cycle longer than 18 hours, may increase the growth rate, especially if 
the plants are not saturated with light. A longer cycle is helpful in small 
gardens, such as under standard four-foot fixtures. 
No matter what the light source, place the lights as close to the tops as 
possible without burning the plants. Pay no attention to the manufacturer's 
instructions for the distance of the plants from the lights; these instructions 
don't apply to a high-energy plant such as Cannabis. With standard-wattage 
tubes, keep the lights from two to six inches above the plant tops. With VHO 
tubes, allow four to eight inches. Maintain the lights at these distances 
throughout the life of the garden. In most cases you will have to raise the 
lights once or twice a week as the plants grow. 
Standard fluorescents don't get hot enough to burn the plants unless they are in 
direct contact with leaves for several hours. VHO tubes will burn leaves before 
they touch them. But you do want to keep the lights as close to the plants as 
possible. This encourages stocky, robust growth. Incandescents and floodlights 
get very hot; place them at a greater distance from the plants. Test the 
distance by feeling for heat with your hands. Place the bulb at the distance 
where you begin to feel its heat. For a 75-watt incandescent lamp, this is about 
eight inches. 
7.4 Water
Water, the fluid of life, makes up more than 80 percent of the weight of the 
living plant. Within the cells, life processes take place in a water solution. 
Water also dissolves nutrients in the soil, and this solution is absorbed by the 
roots. About 99 percent of the water absorbed passes from the roots into the 
conduits (xylem) of the stem, where it is distributed to the leaves via the 
xylem of the leaf veins. Transpiration is the evaporation of water from the 
leaves. The flow of water from the soil, through the plant to the air, is called 
the transpiration stream. Les then one percent of the water absorbed is broken 
down to provide electrons (usually in the form of hydrogen) which, along with 
carbon dioxide, are used to form carbohydrates during photosynthesis. The rest 
of the water is transpired to the air. 
Watering
Water provides hydrogen for plant growth, and also carries nutrients throughout 
the plant in the transpiration stream. However, it is not true that the more 
water given a plant, the faster it will grow. Certainly, if a plant is 
consistently under-watered, its growth rate slows. However, lack of water does 
not limit photosynthesis until the soil in the pot is dry and the plant is 
wilting. 
The amount of water, and how often to water, varies with the size of the plants 
and pots, soil composition, and the temperature, humidity, and circulation of 
the air, to name a few variables. But watering is pretty much a matter of common 
sense. 
During germination, keep the soil surface moist. But once the seedling are 
established, let the top layer of soil dry out before watering again. This will 
eliminate any chance of stem rot. Water around the stems rather than on them. 
Seedlings are likely to fall over if watered roughly; use a hand sprinkler. 
In general, when the soil about two inches deep feels dry, water so that the 
soil is evenly moist but not so much that water runs out the drainage holes and 
carries away the soil's nutrients. After a few trials, you will know 
approximately how much water the pots can hold. Marijuana cannot tolerate a 
soggy or saturated soil. Plants grown in constantly wet soil are slower-growing, 
usually less potent, and prone to attack from stem rot. 
Over-watering as a common problem; it develops from consistently watering too 
often. When the plants are small, they transpire much less water. Seedlings in 
large pots need to be watered much less often than when the plants are large or 
are in small pots. A large pot that was saturated during germination may hold 
enough water for the first three weeks of growth. On the other hand, a six-foot 
plant in a six-inch pot may have to be watered every day. Always water enough to 
moisten all the soil. Don't just wet the surface layer. 
Under-watering is less of a problem, since it is easily recognised. When the 
soil becomes too dry, the plant wilts. Plant cells are kept rigid by the 
pressure of their cell contents, which are mostly water. With the water gone, 
they collapse. First the bottom leaves droop, and the condition quickly works 
its way up the plant until the top lops over. If this happens, water 
immediately. Recovery is so fast, you can follow the movement of water up the 
stem as it fills and brings turgor to the leaves. A plant may survive a wilted 
condition of several days, but at the very least some leaves will drop. 
Don't keep the pots constantly wet, and don't wait until the plant wilts. Let 
the soil go through a wet and dry cycle, which will aerate the soil and aid 
nutrient uptake. Most growers find that they need to water about once or twice a 
week. 
When some soils get particularly dry, the water is not absorbed and runs down 
the sides and out the bottom of the pot. This may be a problem the first time 
you water the soil, or if you allow the soil to get very dry. To remedy, add a 
couple of drops of liquid detergent to a gallon of water. Detergent acts as a 
wetting agent and the water is absorbed more readily. First water each pot with 
about one cup of the solution. Allow the pots to stand for 15 minutes, then 
finish watering with the usual amount of pure water. 
Use tepid water; it soaks into the soil more easily and will not shock the 
roots. Try to water during the plant's morning hours. Water from the top of the 
pot. If you do want to water from the bottom with trays (not recommended), place 
a layer of pebbles or gravel in the trays to insure drainage. Don't leaves the 
pots sitting in water until the pot is heavily saturated. The water displaces 
the soil's oxygen, and the plants grow poorly. 
Tap water in some areas highly chlorinated, which does not seem to harm 
Cannabis; and many fine crops are raised with water straight from the tap. But 
chlorine could possibly affect the plants indirectly, by killing some beneficial 
micro-organisms in the soil. Chlorine also makes the water slightly acidic. 
However, neither effect is likely to be serious. Some growers have asked whether 
they should use pet-shop preparations that are sold to remove chlorine from 
water in fish tanks. These preparations generally add sodium, which removes the 
chlorine by forming sodium chloride (table salt). This solution does not harm 
the plants, although repeated use may make the soil too saline. Probably the 
best procedure is to simply allow the water to sit in an open container for a 
few days. The chlorine is introduced to water as the gas Cl2, which dissipates 
to the air. The water temperature also reaches a comfortable level for the 
plants. 
Hard (alkaline) water contains a number of minerals (e.g., Ca++, Mg++, K+) which 
are essentially nutrients to the plants. Water softeners remove these minerals 
by replacing them with sodium, which forms slightly salty water. It is much 
better to water with hard water, because artificially softened water may prove 
harmful after some time. Occasionally, water may be acidic (sulphurous). 
Counteract this by mixing one teaspoon of hydrated lime per quart water and 
watering with the solution once a month. 
Water and Potency
We've seen no studies that have evaluated potency in relation to water. A few 
studies have mentioned the fact that plants that received less water were 
slightly more potent. Water stress has been practiced by several 
marijuana-growing cultures. In parts of India, watering is kept to a minimum 
during flowering. 
To limit watering, water with the usual amounts but as infrequently as possible. 
To encourage good growth, yet keep watering to a minimum, wait until the plants 
are a few months old before you curtail watering. Give the plants their normal 
water and note the number of days before they begin to wilt. As the plants get 
larger, the water needs increase, but this generally stabilises by the time of 
flowering. 
7.5 Air
The properties of the air seldom present any problems for indoor gardeners. The 
plants grow well under the ordinary conditions that are found in most homes and 
can withstand extremes that are rarely found indoors. The plants can survive, in 
fact thrive, in an atmosphere many house plants can't tolerate. For plant 
growth, the most important properties of the air are temperature, humidity, and 
composition. 
Temperature and Growth Rate
Temperature control should be no problem. The plants can withstand temperatures 
from freezing to over 100F. Plant growth is closely related to temperature. 
Marijuana varieties are, in general adapted to warm if not hot climates. 
Different varieties will reach their maximum rate of photosynthesis at different 
temperatures. For almost all marijuana varieties, the rate of photosynthesis 
will increase sharply with increases in temperatures up to about 70F. Some 
strains reach their peak rate of growth at about &%F. Others, especially from 
areas near the equator, such as Colombia, may not reach their peak rate until 
the temperature is about 90F. However, for all varieties, increases in the 
growth rate will be slight with increased temperatures over 75F. The average 
temperature for maximum is about 75 to 80F. In other words, normal household 
temperatures are fine for growing marijuana and no special temperature control 
is necessary for most gardens. 
Don't set up the garden right next to, or in contact with, a heat source such as 
a radiator or furnace. If the garden is nearby, the plants should do quite well. 
The plants are most susceptible to cool temperatures during germination and the 
first few weeks of growth. In basement gardens, the floor temperature is often 
lower than the air. It is a good idea to raise the pots off the floor with 
pallets or boxes. The seeds will germinate quicker, and the plants will get off 
to a faster start. 
If heating is necessary, propane catalytic heaters work well, are safe and 
clean, and increase the carbon-dioxide content of the air. Electric and natural 
gas heaters also work well. Do not use kerosene or gasoline heaters. They do not 
burn cleanly, and the pollutants they produce may harm the plants. Any heater 
that burns a fuel must be clean and in good working order. Otherwise, it may 
release carbon monoxide, which is more dangerous to you than to the plants. 
Temperature and Potency
Since marijuana varieties are most often grown in semi-tropical and tropical 
areas, the idea that high temperatures are necessary for potent marijuana is 
firmly entrenched in marijuana lore. This myth, like many others, is slowly 
disappearing as marijuana farmers and researchers accumulate more experience and 
knowledge. There are only a few published papers on the effects of temperature 
on potency. The best study we've seen 19 grew four different varieties in a 
controlled environment under artificial lights on a 15-hour day-length. Two 
temperature regimes were used: a "warm" regime, with temperatures of about 73F 
during the day and 61F at night (about average for most homes); and a "hot" 
regime, set at 90F daytime and 73F at night. In all four varieties, the 
concentration of THC and of total cannabinoids was higher under the "warm" 
regime. For instance, a Nepalese strain was 3.4 times higher in concentration of 
total cannabinoids, and 4.4 times higher in THC, when grown under the "warm" 
regime than the same strain grown under the "hot" regime. Although we agree with 
the findings in principle, these figures are higher than our experience tells 
us. 
Interpretation of the data does show one point clearly. In all four varieties, 
the amount of THC lost as CBN was higher under the "hot" regime (see Table 16 - 
currently excluded from this guide), even though the concentration of THC was 
higher under the "warm" regime. 
Another research group in France has looked at the relationship of potency to 
temperature. The most recent paper 79 compared four temperature regimes, given 
in descending order of potencies found: 75F day, 75F night (highest potency); 
72F day, 54F night; 81F day, 81F night; and 90F day, 54F night (lowest 
concentration of THC). In each, the day period was 16 hours and the night period 
eight hours. 
Interestingly, this same research group in an earlier paper 20 reported that the 
concentration of THC was higher for male plants grown at 90-72F then for those 
grown at 72-54F. For the female plants, the differences in THC concentration 
were small. The variety used was a propyl variety (type IV) containing about 
half as much THCV as THC. For both the male and female plants, the concentration 
of THCV were high under the 90-72F regime. 
The simplest interpretation of all these results is that mild temperatures seem 
to be optimum for potency. Temperatures over 90F or below 60F seem to decrease 
the concentration of THC and total cannabinoids. Also, at higher temperatures, 
much more THC will be lost as CBN. And last, propyl varieties may produce less 
THCV under a cool regime. Bear in mind that none of these papers accounted for 
all of the many variables that could have affected the findings. For instance, 
the concentration of THC was 18 times higher at 75-75F than at 90-54F. We've 
never seen differences of this magnitude, and sampling error undoubtedly 
influenced the findings. 
In terms of growth rate and potency, daily temperatures of about 75F, give or 
take a few degrees, are roughly optimum. Normal household temperatures are in 
the low 70's during daytime and the low 60's at night. The heat from a light 
system will raise the garden's temperature a few degrees. In most gardens 
temperatures will be near 75F during the day. Night-time temperatures drop about 
10 to 15 degrees. When night-time temperatures drop into the 50's or below, set 
the light cycle to turn on during the early morning, when the temperature will 
be lowest. In a small room, the light system will generate enough heat to warm 
the garden without any need for a heater. Whenever you wish to raise the 
temperature by, say, five or 10 degrees, it is better to add more lights than a 
heater. The plants will benefit from the additional light, as well as from the 
heat they generate. And an electric heater, watt for watt, doesn't generate much 
more heat than a lamp and its fixture. 
Composition of the Air
Air provides two essential ingredients for the living plant: oxygen and carbon 
dioxide. The plant uses oxygen for respiration in the same way we do. The oxygen 
is used to burn carbohydrates (CH2O) and other food, yielding energy (ATP; see 
section 4) for the organism, and releasing carbon dioxide and water into the 
environment. 
During photosynthesis, CO2 is used to form carbohydrates. As part of 
photosynthesis, light energy is used to split water molecules, releasing oxygen 
into the environment. In plants, the net result from respiration and 
photosynthesis is that much more oxygen is released than consumed, and more 
carbon dioxide is consumed than released. The oxygen in the Earth's atmosphere 
is formed by photosynthetic organisms. 
The similarity between plant and animal respiration ends at a cellular level. 
Plants don't have lungs to move the air. The passage of gases, whether oxygen or 
carbon dioxide, is primarily a passive process. The gases diffuse through 
microscopic pores called stomata, found in Cannabis on the undersides of the 
leaves. The plants can open and close their stomata, allowing moderate control 
of the flow of air. However, for good exchange of gases, the plants require 
adequate ventilation for air circulation. {Cannabis is a C3 plant} 
Cannabis is not particularly susceptible to a stuffy or stagnant atmosphere. A 
garden in the corner of a room that is open to the house will be adequately 
ventilated. Ventilation is not a problem unless the garden is large and fills a 
quarter or more of the space in a room. Gardens in small, confined spaces such 
as closets, must be opened daily, preferably for the duration of the light 
period. Plants growing in a closed closet may do quite well for the first month, 
but they'll need the door opened as the plants begin to fill the space. The 
larger the plants get, the greater the need for freely circulating air. 
When the weather is mild, an open, but screened, window is the best solution for 
ventilation. In large indoor gardens where there isn't much air circulation, a 
small fan is helpful. After germination, make spaces in the surrounding 
reflectors to allow air to circulate freely. Leave the spaces at the bottom, 
ends, and the tops of the garden. The higher the temperature or the humidity, 
the more the plants need good ventilation. 
CO2
CO2 is a natural, non-poisonous gas present in the atmosphere, which plants 
absorb and use during photosynthesis to synthesise sugars and organic compounds 
for energy and growth. Plants can effectively use CO2 up to about .15 percent 
concentration, about five times the concentration (.03) naturally present in the 
atmosphere. Increasing the CO2 dramatically increases the growth rate, often up 
to twice the rate of growth in plants in a natural atmosphere. Supplemental CO2 
systems are an inexpensive way serious gardeners dramatically increase a 
garden's yield. {And decrease fire risk.} {Picture Common emitter systems are 
safe, inexpensive, easy to setup, and may double the rate of growth in a 
garden.} 
There are two good ways to increase the concentration of CO2. Greenhouse growers 
use CO2 generators which produce CO2 by burning a clean-burning fuel such as 
propane or butane. The problems with CO2 generators are that they require a 
fuel, operate with an open flame, and produce a lot of heat. These are not 
necessarily problems if the grow room needs to be heated, and if the room is 
constantly monitored. 
For home-growers, the emitter system is more efficient, relatively cheap, safe, 
and easy to use. Many suppliers who advertise in High Times and Sinsemilla Tips 
offer complete emitter systems that come with a regulator, solenoid valve, 
flow-meter, timer, (sometimes distribution tubing), and detailed, yet simple 
instructions. You must rent compressed CO2 gas tanks from a local compressed gas 
supplier or beverage company. The setup is not complicated or expensive, and a 
walk through the Yellow Pages should show several suppliers. 
Since the CO2 in the atmosphere is about .03 percent, and the maximum CO2 
concentration that your plants use is about .15 to .2 percent, set your emitter 
system to regulate a concentration of .12 to .17 percent CO2 in the room. Don't 
worry if you don't understand. All systems are easy to install and come with 
easily understood instructions. 
7.6 Humidity
Marijuana flourishes through a wide range of relative humidity. It can grow in 
an atmosphere as dry as a desert or as moist as a jungle. Under ordinary 
household conditions, the humidity will rarely be too extreme for healthy 
growth. The effects of the humidity on plant growth are closely tied to 
temperature, win speed, and the moisture of the soil. 
The relative humidity affects the rate of the plant's transpiration. With high 
humidity, water evaporates from the leaves more slowly; transpiration slows, and 
growth slows also. With low humidity, water evaporates rapidly; the plant may 
not be able to absorb water fast enough to maintain an equilibrium and will 
protect itself from dehydration by closing its stomata. This slows the 
transpiration rate and growth also slows. There is a noticeable slowing of 
growth because of humidity only when the humidity stays at an extreme (less then 
20 percent or over 90 percent). 
Cannabis seems to respond best through a range of 40 to 80 percent relative 
humidity. You should protect the plants from the direct outflow of a heater or 
air conditioner, both of which give off very dry air. During the first few weeks 
of growth, the plants are especially susceptible to a dry atmosphere. If this is 
a problem, loosely enclose the garden with aluminum foil, white sheet plastic, 
or other materials. This will trap some of the transpired moisture and raise the 
humidity in the garden. Once the seedlings are growing well, the drier household 
atmosphere is preferred. 
Where the humidity is consistently over 80 percent, the plants may develop stem 
rot or grow more slowly. Good air circulation from open windows or a small fan 
is the best solution. 
As long as the air is freely circulating, the plants will grow well at higher 
humidities. Dehumidifiers are expensive (over $100) and an extravagance. 
Humidity and Potency
As far as we know, there has been little work done correlating the relative 
humidity with potency. In the two related cases we've seen, 85, 117 neither 
study was intended to examine the effects of relative humidity and potency. 
However, a lower humidity (50 to 70 percent) produced slightly more potent 
plants than a higher relative humidity (80 percent and over). 
A dry atmosphere seems to produce more potent plants. When the humidity is about 
50 percent or less, plant development is more compact, and the leaves have 
thinner blades. When the atmosphere is humid, growth is taller and the leaves 
luxuriant with wider blades. The advantage to the plant is that wider blades 
have more surface and hence can transpire more water. The converse is that 
thinner blades help conserve water. Higher potency may simply be due to less 
leaf tissue for a given amount of cannabinoids and resin glands. 
The temperature also influences the form and size of the leaves. At higher 
temperatures, the leaves grow closer together; under a cool regime, the leaves 
are larger, have wider blades, and are spaced farther apart 77. Possibly, cool 
temperatures yield slightly lower potency for much the same reason that a moist 
atmosphere does. 
However, differences in potency caused by any of the growth factors (light 
nutrients, water, temperature, humidity, etc.) are small compared to differences 
caused by the variety (heredity) and full maturation (expression of heredity). 
For example, the humidity in Jamaica, Colombia, Thailand, and many other 
countries associated with fine marijuana is relatively high and averages about 
80 percent. 
However, try to keep the atmosphere dry. The atmosphere in heated or 
air-conditioned homes is already dry (usually 15 to 40 percent). For this 
reason, many growers sow so that the plants mature during the winter if the home 
is heated or in mid-summer if it is air-conditioned. As we mentioned, there 
should be no need to use dehumidifiers. Good air circulation and raising the 
temperature to 75 to 80F are the simplest means of dealing with high humidity. 



Chapter Eight
GARDENING TECHNIQUES
8.2 Thinning
Depending on the viability of the seeds, there should be several plants growing 
in each pot. Most growers thin to one plant per pot, but the plants don't have 
to be thinned until they crowd each other and have filled the garden with 
foliage. The longer you let them grow, the more potent they'll be. 
It is virtually impossible to tell the gender of the plants when they are young. 
The normal ratio of males to females in Cannabis is one to one. Some farmers end 
up wit more male plants because of their thinning practices. When the plants are 
less than a month old, the male plants often appear taller and better developed 
than the females. The male seedling uses more of its energy to develop its 
aboveground parts than the female. The female devotes more energy to 
establishing a strong root system. During the first few weeks, don't thin the 
plants by leaving only the tallest, or you'll wind up with a higher ratio of 
males. Try to leave seedling that are healthy and vigorous and that are roughly 
at the same point of development. 
To thin your garden, remove any plants with yellow, white, or distorted leaves. 
Remove the less vigorous and those that lag far behind in development. Cut the 
unwanted plants near the base; the root system can remain in the pot. 
These harvested seedlings will be your first taste of homegrown grass. Usually 
they produce a mild buzz, but if you separate the growing tips from the large 
leaves, they may be more potent. 
8.3 Transplanting
However you transplant, try to disturb and expose the roots as little as 
possible. If you transplant carefully, the plants will not exhibit delayed or 
slowed growth due to transplant shock. 
Transplanting Seedlings
When the plants are a week to two weeks old, transplant to any pot that has no 
plants. First, moisten the soil in the pot from which you will remove the 
transplant and let is sit for a few minutes. Take a spade or a large spoon, and 
insert it between the transplant and the plant that will be left to grow. Try to 
leave at least one inch of space from spoon to stem. Lever the spoon toward the 
side of the pot, in order to take up a good-size wedge of soil. Place the 
transplant in a prepared hole at the same depth that it was growing before. 
Replace the soil in both pots and moisten lightly again to bond the new soil 
with the original. If you are careful, a wedge of soil can be removed intact. 
The root system will not be disturbed and the plant will survive with little or 
no transplant shock. Do not fertilise a transplant for two weeks. 
To prevent possible drop-off and wilting from shock, you may want to use Rootone 
or Transplantone. These safe powders, available at nurseries, contain 
root-growth hormones and fungicides. They won't be necessary if you transplant 
carefully. 
Transplanting to Large Pots
Transplanting from smaller to larger pots is a simple procedure. The marijuana 
root system quickly fills small pots. To transplant, moisten the soil and let it 
sit to become evenly moist. Pick the potted plant up, and, while holding the 
base of the stem, rap the pot sharply against something solid. You might cover 
the soil surface with a piece of newspaper or aluminium foil, which makes the 
job cleaner. When it is done at the right time, the root system, with all the 
soil adhering, will pop out of the pot intact. 
An approximate time guide for transplanting is shown in Table 17(currently 
excluded from this guide). At these times, give or take a week, the plants 
should be root-bound and all the soil will adhere to the roots, making the 
transplanting clean and easy. 
If the root system has not filled the pots by this time, wait a few weeks and 
the process will be easier. If the root system comes out in a small ball and 
much of the soil is empty of roots, then soil conditions are poor (usually poor 
drainage and over-watering) or you are transplanting much too seen. 
If the root system doesn't easily pop out, run a knife around the sides of the 
pot. Sometimes the roots stick to the sides, particularly is paper and clay 
containers. Check to see if the drainage holes are plugged. Plugged holes stop 
air from displacing the soil, and the vacuum pressure prevents the soil from 
sliding out of the pot. 
	Table 17
	Guide for Transplanting
Transplant				During
------------------------------------------------------------
Six-ounce cups				Second to third week
Four-inch pots				Third to fourth week
Six-inch pots (half gallon)             Fourth to fifth week
Eight-inch pots (one gallon)            Seventh to eighth week
Two-gallon containers                   About the tenth week
Transplant into a soil mixture that is the same as (or is very like) the one in 
the original pots. Otherwise, the soils may have different osmotic properties, 
and the water may not disperse evenly. (This doesn't apply to small pots that 
are used for germination and are filled with vermiculture, Jiffy Mix, or other 
mediums.) Don't bury the stem. Keep the stem base at the same depth that it was 
growing. {Figure 47. Transplant when the plant is root-bound.} 
Transplanting in Plastic Bags
To transplant plants that are in plastic bags, place the old bag into the 
larger-size bag. Put some soil mixture underneath, to bring the base of the stem 
to where the new soil surface will be. Cut the old plastic bag away and fill the 
side spaces with soil mixture. Two people make the job easier. 
8.4 Supports for Plants
Under natural conditions, stems undergo stress from wind, rain, and animals. 
These stresses, which indoor plants do not ordinarily face, strengthen the stem. 
Indoor stems grow sturdy enough to support their own weight and not much more. 
Plant energy is used to produce more light-gathering leaf tissue, rather than 
wind-resistant stem tissue. Stems remain slender, usually about one-half to 
three-quarter inches at maturity. Since you are growing the plants for their 
leaves and flowers, this does not present a problem. 
Healthy plants do not ordinarily need support. If many of your plants have weak 
or spindly stems, there is a deficiency in either light or nutrients (notably 
potassium). Simply not having enough light will cause the plants to elongate, 
with sparse foliage and weak growth. Too much red light will cause elongation, 
too, so make sure you include a strong blue light, if you are using 
incandescents or floodlights. 
Hanging the lights higher than the recommended distances will cause the plants 
to elongate by rapidly growing up to the lights. Unlike sunlight, the intensity 
of artificial light diminishes dramatically with the distance from the lights. 
The plants respond by growing toward the light, seeking the higher intensity. 
Under artificial light, some plants may need support during the seedling stage 
or because of accident. Depending on plant size, use straws, pencils, dowels, or 
standard plant stakes such as cane sticks. Set them in the soil and affix the 
stem with string, masking tape, or wire twists such as those that come with 
plastic trash bags. Do not tie string or wire tightly around the stem; make a 
loose loop. The stem will grow in girth and can be injured by a tight loop. 
Probably the simplest method of support is to take a rigid piece of wire, form a 
"C" at one end and bend it to a right angle to the stem. Set the straight end in 
the soil and place the stem inside the "C." Pipe cleaners are ideal for 
seedlings. With larger plants, straighten a coat hanger and use the same method. 

A common practice in greenhouses where tree seedlings are raised is to shake 
each plant once or twice daily. This practice simulates natural vibrations from 
the wind, and the plant reacts by increasing the growth around the stem. The 
stem grows thicker and stronger, and the tree can better fend once it is 
transplanted. It works the same way with marijuana. A fan blowing on the plants 
will also work. These practices are useful if you plan to move your plants 
outdoors. Otherwise, healthy indoor plants that will remain indoors need no 
special stem strengthening. 
8.5 Uniform Growth
The light intensity from artificial lights drops dramatically as the distance 
from the light source increases. When the plants are not of equal height, the 
shorter ones receive less light and consequently grow slower than the taller 
ones. This compounds the situation and, left to themselves, the shorter plants 
will stop growing and eventually die from lack of light. 
It is important to keep all of the plants close to the lights. {Figure 48. Hang 
the fixture at an angle corresponding to that of the tops of the plants.} This 
encourages stocky, full growth and can make the difference between harvesting 
stems and harvesting smoking material. 
One way to deal with uneven height is to line the plants up to the line of the 
plant tops. As the plants grow, move them to different spots in the garden to 
accommodate their different sizes. Or raise the shorter plants up to the lights 
by placing them on milk crates, tin cans, bricks, etc. 
The quality and quantity of light emitted by a fluorescent is strongest in the 
middle and weaker toward the ends of the tube. Female plants require more light 
than males. Once the genders of the plants become clear, move the males to the 
ends of the system, thus leaving the stronger middle light for the females. 
8.6 Pruning
Probably the easiest way to deal with uneven growth is to cut back the taller 
plants to the average height. You may find this emotionally difficult, but 
pruning will not harm the plant. Cutting off the growing shoot forces the plant 
to develop its branches. Some growers cut back all of their plants when they are 
three to four weeks old. Any horizontal space is quickly filled with growing 
branches and the plants grow full and robust. 
The growing shoots are the most potent plant parts until the flowers appear. 
Generally, the potency increases with growth. By three months' age, most shoots 
will be high-quality smoke. You can cut shoots at any time; just don't overdo 
it. Give the plant a chance to grow and fill out to a good size. Severe pruning 
will slow growth. New growth may be distorted and abnormal, with a drop in 
potency. 
Each time you cat a growing shoot, whether it is the stem tip or a branch tip, 
two shoots being to grow from the nearest leaf axils. However, don't think that 
cutting all the growing shoots of a plant twenty times over the course of a 
season will yield a plant bearing over a million new shoots, or even that the 
plants will double their size if pruned. Pruning simply allows the plant to 
develop its branches earlier. The branches present more area to gather light 
and, hance, can grow to fill a larger space. However, the plant's size is 
basically determined by the seed's potential within the limitations of the 
environment. 
Cutting the growing shoots or removing some leaves does not harm the plants. 
Plants are well adapted to the loss of parts to predators, wind, etc., in the 
natural world. When leaves are damaged or lost, the plant plugs the wound. The 
leaf isn't replaced or repaired, but new leaves are continually being formed 
from the growing shoots. The stem, since it connects all parts of the plant, is 
more important to the plant as a whole. When the stem breaks or creases, it is 
capable of repair. You can help the plant repair its stem by splinting the wound 
or somehow propping the stem up straight. Stems take about four or five days to 
heal. 
When you cut the stem or leaves, you may see the plant's sap momentarily spurt 
before the wound is plugged. The sap contains primarily the products of 
photosynthesis, in the form of sucrose (table sugar). Smaller amounts of 
materials associated with the living organism such as minerals, amino acids, and 
enzymes are also present. In marijuana, the sap is usually colourless, although 
a bright red colour - it looks like blood - is not uncommon in later life. The 
red colour is due to haematin compounds and anthocyanin pigments that naturally 
build up in some varieties. The red colour may also indicate a nutrient 
deficiency, notably of nitrogen, phosphorus, potassium, or magnesium. 
8.7 Training
Plants grow from the tips of their stems and branches. The growing tip (apical 
meristem) of the plant contains a hormone that acts as a growth inhibitor. This 
prevents the branches (lateral buds) from growing. The further a branch is from 
the growing tip, the less effect of the inhibitor. This is why some species of 
plants form a cone or Christmas-tree shape with the longest branches toward the 
bottom of the stem. This is also why the branches grow from the top of the plant 
when the tip is removed. Once the growing tip is removed, the next highest 
growing shoot(s) becomes the source of the inhibitor. Under artificial light, 
the bottom branches may not receive enough light to grow even though they are 
far away from the inhibitor. Usually the longest branches are toward the middle 
of the plant. 
Some growers hate to cut the growing shoots on the main stem, since it forms the 
largest and most potent buds by harvest. But you can neutralise the effects of 
the inhibitor, without cutting the growing shoot, by bending the tip. This 
allows you to control the height of the plants, and forces them to branch. The 
top two to six inches of the stem are flexible. Bend it in an arc and secure it 
to the stem with a wire twist or string. Remove the wire twist in a few days so 
that the growing tip does not break itself as it twists up to the light. Don't 
bend the stem too far down. Keep it in the strong light or else it will stop 
growing. If you accidentally break the tip, you can splint it with matchsticks 
or ice-cream sticks secured with wire twists or tape until it heals. {Figure 49. 
The flexible tip is held in place with a wire twist.} 
To develop large, full plants with well-developed branches, secure the growing 
tip once or twice for a few days while the plants are young (one to three 
months). 
It is possible to train the tip so that the stem will form a series of "S" 
shapes or even circles. During flowering, train the tips so that they grow 
horizontally. This method encourages thick, dense growth. The branch tips can 
also be trained. Keep bending any tips that grow above the others. This creates 
a garden filled with a cubic layer of vigorous flower clusters rather than a lot 
of stems. 
We want to emphasise that when you get the knack of training the tips, you can 
more than double the yield of the most potent plant parts. {Figure 50. Stem 
trained in an "S" shape.} {Figure 51. Tops trained horizontally during 
flowering.} 



Chapter Nine
NUTRIENTS AND FERTILISING
9.2 Nutrients
There are about 15 elements known to be essential to plant life. Carbon, 
hydrogen, and oxygen are absorbed from air and water. The remaining 12 elements 
are absorbed primarily from the soil, in mineral (inorganic) forms such as NO3- 
and K+. They constitute a natural part of soil that becomes available to the 
plant os organic matter decays and soil particles such as sand and clay 
dissolve. 
Soil elements that are necessary for normal growth are called nutrients. The 
elements nitrogen (N), phosphorous (P), and potassium (K) are considered major 
nutrients. The three numbers that appear on all fertiliser packages give the 
available percentage of these three nutrients that the fertiliser contains; and 
always in the order N-P-K. For example, 10-2-0 means 10 percent N, 2 percent P 
(actually, 2 percent P2O5), and no K (actually, no K2O). Fertility is often 
measured by the amounts of major nutrients a soil contains. Relatively large 
amount of N-P=K are needed for lush growth. 
Three other elements - calcium (Ca), sulphur (S), and magnesium (Mg) - are 
called secondary nutrients. Plants require less of these nutrients, and most 
cultivable soils contain adequate amounts for good growth. 
Six remaining elements are called trace elements or micronutrients. As their 
name implies, they are needed in very small amounts. Commercial soils contain 
enough trace elements to sustain normal growth. The trace elements are also 
present in manures, humus, ash, and limestone. 
Nitrogen
The amount of nitrogen a soil can supply is the best indication of its 
fertility. Nitrogen, more than any other soil nutrient, is inextricably linked 
with the living ecosystem. Nitrogen is continually cycled through living 
systems: from soil to plants and back to the soil, primarily by the activity of 
soil microorganisms. Nitrogen is essential to all life. Nitrogen is a key 
element in the structure of amino acids, the molecules which make up proteins. 
These, and all other biomolecules, are synthesised by the plant. Chlorophyll, 
genetic material (for example, DNA), and numerous enzymes and plant hormones 
contain nitrogen. Hence, N is necessary for many of the plant's life processes. 
Cannabis is a nitrophile, a lover of nitrogen. Given ample N, Cannabis will 
outgrow practically and plant. Ample nitrogen is associated with fast, lush 
growth, and the plant requires a steady supply of nitrogen throughout its life. 
Marijuana's requirements for N are highest during the vegetative growth stages. 
Phosphorous
P is a constituent of energy-transfer compounds such as NADP and ATP, and 
molecular complexes such as the genes. The energy compounds are necessary for 
photosynthesis, respiration, and synthesis of biomolecules. Cannabis takes up 
large amounts of P during germination and seedling stages. During flowering and 
seed set, Cannabis' need for phosphorous is also high. 
Potassium
K influences many plant processes, including photosynthesis and respiration, 
protein synthesis, and the uptake of nutrients. Just as with P, K uptake is 
highest during the earliest growth stages. K is associated with sturdy stems and 
resistance to disease in plants. 
Calcium
Ca functions as a coenzyme in the synthesis of fatty compounds and cell 
membranes, and is necessary for normal mitosis (replication of cells). Plants 
take up much more Ca than the small amount necessary for normal growth. Ca is 
not added to soil as a nutrient; is added to adjust the soil's chemistry or pH. 
Sulfur
S is a constituent of certain amino acids and proteins. It is an important part 
of plant vitamins, such as biotin and thiamine, which are necessary for normal 
respiration and metabolism. (Plants synthesise all vitamins they need.) Most 
soils suitable for growing marijuana contain plenty of S. 
Magnesium
Mg is involved in protein synthesis and metabolism of carbohydrates. Mg is the 
central element in the structure of chlorophyll molecules and hence has an 
important role in photosynthesis. Most mineral soils and commercial soils have a 
good supply of Mg. 
Trace Elements
The trace elements (Fe, Mn, Mb, B, Cu, Zn) are particularly important in the 
coenzymes and catalysts of the plant's biochemistry. Many life processes, 
particularly the synthesis and degradation of molecules, energy transfer, and 
transport of compounds within the plant, depend on trace elements. Trace 
elements are not used in large quantities to spur growth, but are necessary in 
minute amounts for normal growth. Indoor soils rarely require an addition of 
trace elements. 
All the nutrients are needed for normal growth. However, most of them are 
supplied by the potting soil. Ca, S, and the trace elements rarely present any 
problems. For most growers, fertilising will simply require periodic watering 
with a complete fertiliser, one that contains N, P, and K. 
9.3 Application: Fertilising
To grow to a large size, marijuana requires a steady supply of nutrients. These 
can be added to the soil before planting or anytime during growth. Bulk 
fertilisers are added while the soil is mixed, as described in section 6. These 
include manures, composts, humus, and concentrated fertilisers, such as rose 
food. Once the plants are growing, never condition or mulch indoor soils with 
bulk fertilisers. they promote moulds and fungi and attract other pests to the 
garden. Concentrated fertilisers can damage the plants if they come in direct 
contact with the stem or roots. 
While the plants are growing, nutrients are given in solution; they are 
dissolved in water, and the plants are watered as usual. Soluble fertilisers can 
be either organic or inorganic (chemical), and come in a wide range of 
concentrations and proportions of nutrients. Two organic fertilisers are liquid 
manure (about 1.5-1.0-1.5) and fish emulsion ((Some fish emulsion may contain 
whale by-products.)) (about 5-1-1). Chemical fertilisers commonly may have 
20-20-20 or 5-10-5, or may contain only one nutrient, such as 16-0-0. 
A 10-5-5 fertiliser is 20 percent soluble nutrients and 80 percent inert 
ingredients. a 30-10-10 has 50 percent available nutrients and 50 percent inert 
ingredients. There is approximately the same amount of N in one tsp. of 30-10-10 
as in three tsps. of 10-5-5. 
Actually, you can almost use any fertiliser, but the nitrogen content should be 
proportionately high, and there should be some P and L also present. For 
example, a 20-20-20 would work fine, as would a 12-6-6 or a 3-4-3, but not a 
2-10-10 or a 5-10-0. 
How much fertiliser to use and how often to fertilise depend primarily on the 
fertility of the soil and the size of the container relative to the size of the 
plant. Small plants in large pots usually do not need to be fertilised. Even in 
small pots, most plants do not need to be fertilised for at least the first 
month. 
As the plants grow, they take nutrients from the soil, and these must be 
replaced to maintain vigorous growth. During the vegetative stage, even plants 
in large pots generally require some fertilising, particularly with N. 
The rate of growth of indoor plants is usually limited by the amount of light 
and space, once adequate nutrients are supplied. At this point, an increase in 
nutrients will not increase growth. Your goal is to supply the plants with their 
nutritional needs without overfertilising and thus toxifying the soil. 
Most fertilisers are designed for home use and have instructions for fertilising 
houseplants. Marijuana is not a houseplant, and it requires more nutrients than 
houseplants. The extra nutrients that it needs may be supplied by the use of 
large pots and a fertile soil mixture. In many cases, you will need to fertilise 
only in the dosages recommended on fertiliser packages for houseplants. For 
instance, Rapid-Gro (23-19-17) is popular among marijuana growers; use one 
tablespoon per gallon of water every two weeks. 
A typical program for fertilising might be to fertilise during the fifth week of 
growth and every two weeks thereafter until flowering. Then discontinue 
fertilising (or give at one-half concentration) unless the plants show a 
definite need for nutrients. It is better to fertilise with a more diluted 
solution more often than to give concentrated doses at longer intervals. (For 
instance, if instructions call for one tablespoon of fertiliser per gallon once 
a month, use one-quarter tablespoon per gallon once a week.) 
Make sure that a fertiliser is completely dissolved in the water before you 
apply it. Put the recommended amount of fertiliser in a clear glass bottle and 
mix with about one cup of water. Shake vigorously and then allow it to settle. 
If any particles of fertiliser are not dissolved, shake again before adding the 
rest of the water. If you have difficulty getting all the fertiliser to 
dissolve, first add hot top water. If the fertiliser still does not completely 
dissolve, you should use another fertiliser. 
Never fertilise a dry soil or dry Soilless medium. If the medium is dry, first 
water with about one-half quart of plain water per pot. Let the pots sit for 
about 15 minutes so that the water is evenly dispersed in the pot. Then 
fertilise as usual. 
It is difficult to give instruction for fertilising that will cover all garden 
situations. You want to supply the plant with its nutritive needs, but 
overfertilising con toxify the soil. Fertilising according to instructions for 
houseplants (both in frequency and concentration) should not toxify the soil. 
However, the plants may sometimes require more frequent or more concentrated 
fertilising. A good way to judge the plant's needs is not to fertilise one 
plant, double the fertiliser of another plant, and give the rest of the plants 
their normal dose. If the unfertilised plant grows more slowly, or shows 
symptoms of deficiencies, then probably all the plant are depending on soluble 
fertilisers and must be fertilised regularly. If the plants receiving the double 
dose grows faster than the other plants, increase the other plants' supply also. 
On the other hand, if there is little difference among the plants, then the soil 
is providing the plants with enough nutrients, and they either should not be 
fertilised or should be fertilised with a less-concentrated solution. 
Because they are grown in a relatively small area, it is easy to overfertilise 
indoor plants. When plants are vigorous, look healthy, and are growing steadily, 
don't be anxious to fertilise, particularly if you have already fertilised 
several times with soluble fertilisers. Slow growth or symptoms of deficiencies 
clearly indicate the need for fertilising. 
Overfertilising
In an effort to do the best for their plants, some people actually do the worst. 
Overfertilising puts excessive amounts of nutrients in the soil, causing toxic 
soil conditions. Excessive amounts of one nutrient can interfere with the uptake 
of another nutrient, or change normal plant-soil relations. Since it takes time 
for a build-up to occur high concentrations of nutrients generally encourage 
excellent growth until the toxic level is reached. 
It takes less N than other nutrients to toxify the soil; hence there is less 
margin for error when using N. Too much N changes the osmotic balance between 
plant and soil. Instead of water being drawn into the plant, water is drawn away 
and the plant dehydrates. The leaves feel limp even though the plant is well 
watered. The plant will soon die. This tips of the leaves die first and very 
rapidly the leaves change colour, usually to gold, but sometimes to a brown or 
green-grey. This change in the plants is faster, more dramatic, and more serious 
than for any kind of nutrient deficiency. 
You can save the plants by immediately leaching the pots as soon as the 
condition is recognised. Place the pots outdoors or in a sink or bathtub. 
Discard the top inch or two of loose dirt. Run lukewarm water through the soil 
until a gallon of water for each two gallons of soil has passed through each 
pot. The leaves recover turgor in one or two days if the treatment works. 
Foliar Feeding
Foliar feeding ((Nitrogen fertilisers are usually NO3 (nitrate) or NO2 
(nitrite), substances which are also used to preserve food. They have been shown 
to undergo reactions to form carcinogenic substances (nitrosamines). As with 
eating food treated with nitrates and nitrites (hot dogs, sandwich meats, etc.), 
there is a possibility that such substances might be ingested by eating or 
smoking foliar-fed plants.)) (spraying the leaves with fertiliser) is a good way 
to give the plants nutrients without building up the amount of soluble 
substances in the soil. After the first month, foliar feed the plants with, for 
example, fish emulsion or a chemical fertiliser. Use any fertiliser that states 
it can be used for foliar feeding even if it says "not recommended for foliar 
feeding houseplants." Use a fine-mist sprayer, such as a clean Windex or 
Fantastik bottle. Dilute the fertiliser according to directions (fish emulsion 
at one tablespoon per gallon) and spray both sides of the leaves. When foliar 
feeding, you should spray the plants with plain water the next day, to dissolve 
unabsorbed nutrients and clean the plants. 
Foliar spraying is also a good way to treat plants suffering from nutrient 
deficiencies. Some nutrient deficiencies actually are caused by the soil's 
chemistry, rather than by the absence of the nutrient in the soil. Addition of 
the necessary nutrient to the soil may not cure the plants' problem, because the 
nutrient becomes locked in the soil, or its uptake may be limited by high 
concentrations of other elements present in the soil. Foliar feeding is direct, 
and if the plant's deficiency symptoms do not begin to clear up, then the 
diagnosis is probably incorrect. 
9.4 Nutrient Deficiencies
Before Diagnosing
Before you assume the plant has a nutrient deficiency, make sure the problem is 
not due to other causes. Examine the plant leaves, and along the stem and in the 
soil. 
Even under the best conditions, not all leaves form perfectly or remain 
perfectly green. Small leaves that grew on the young seedling normally die 
within a month or two. Under artificial lights, bottom leaves may be shielded 
from the light, or be too far away from the light to carry on chlorosynthesis. 
These leaves will gradually turn pale or yellow, and may form brown areas as 
they die. However, healthy large leaves should remain green at least three to 
four feet below the plant tops, even on those plants under small light systems. 
Under low light, the lower-growing shoots as well as the large leaves on the 
main stem are affected. Some symptoms of nutrient deficiencies begin first at 
the bottom of the plant, but these symptoms generally affect the lower leaves on 
the main stem first, and the progress to the leaves on the branches. 
Although some deficiency symptoms start on the lower, older leaves, others start 
at the growing shoots or at the top of the plants. This difference depends on 
whether or not the nutrient is mobile and can move from the older leaves to the 
active growing shoot. Deficiency symptoms of mobile nutrients start at the 
bottom of the plant. Conversely, deficiency symptoms of immobile nutrients first 
appear on the younger leaves or growing shoots at the top of the plant. N, P, K, 
Mg, B, and Mb are mobile in the plant. Mn and Zn are less mobile, and Ca, S, Fe, 
and Cu are generally immobile. 
A dry atmosphere or wet soil may cause the blade tips to turn brown. Brown leaf 
tips also may indicate a nutrient deficiency, but in this case, more tissue will 
turn brown than just the end tips. 
Chlorosis and necrosis are two terms which describe symptoms of disease in 
plants. Chlorosis means lacking green (chlorophyll). Chlorotic leaves are pale 
green to yellow or white. Chlorotic leaves often show some recovery after the 
necessary nutrient is supplied. Necrosis means that the tissue is dead. Dead 
tissue can be gold, rust, brown, or grey. It is dry and crumbles when squeezed. 
Necrotic tissue cannot recover. 
Symptoms of deficiencies of either N, P, or K have the following in common: all 
involve some yellowing and necrosis of the lower leaves, and all are accompanied 
by red/purple colour in stems and petioles. The simplest way to remedy these 
deficiencies is to fertilise with a complete fertiliser containing nearly equal 
proportions of three nutrients. 
Nitrogen
N is the most common deficiency of Cannabis indoors or out. Nitrogen 
deficiencies may be quite subtle, particularly outdoors, where the soil may 
continuously provide a small amount of nitrogen. In this case the opt of the 
plant will appear healthy, and the plant will grow steadily, but at a slow pace. 
The deficiency becomes more apparent with growth, as more and more of the lower 
leaves yellow and fall. The first sign is a gradual, uniform yellowing of the 
large, lower leaves. Once the leaf yellow, necrotic tips and areas form as the 
leaves dry to a gold or rust colour. In small pots, the whole plant may appear 
pale (or lime colour) before many bottom leaves are affected to the point that 
they yellow or die. Symptoms that accompany N deficiency include red stems and 
petioles, smaller leaves, slow growth, and a smaller, sparse profile. Usually 
there is a rapid yellowing and loss of the lower leaves that progresses quickly 
to the top of the plant unless nitrogen is soon added. 
Remedy by fertilising with any soluble N fertiliser or with a complete 
fertiliser that is high in N. If your diagnosis is correct, some recovery should 
be visible in three or four days. Pale leaves will regain some colour but not 
increase in size. New growth will be much more vigorous and new stems and 
petioles will have normal green colour. 
Indoors, you should expect plants to need N fertilisation a few times during 
growth. Once a plant shows N deficiency, you should fertilise regularly to 
maintain healthy and vigorous growth. Fertilise at about one-half the 
concentration recommended for Soilless mixtures. Increase the treatment only if 
the plants show symptoms again. Once the plants are flowering, you may choose 
not to fertilise if the plants are vigorous. They will have enough N to complete 
flowering and you don't want to chance toxifying the soil at this late date. 
Phosphorous
P deficiency is not common indoors, but may appear outdoors, particularly in 
dry, alkaline soils or in depleted soils, or during cool weather. Phosphorus 
deficiency is characterised by slow and sometimes stunted growth. Leaves overall 
are smaller and dark green; red colour appears in petioles and stems. The leaves 
may also develop red or purple colour starting on the veins of the underside of 
the leaf. Generally the tips of most of the leaf blades on the lower portion of 
the plant die before the leaves lose colour. Lower leaves slowly turn yellow 
before they die. Remedy with any soluble P-containing fertiliser. Affected 
leaves do not show much recovery, but the plant should perk up, and the symptoms 
do not progress. 
Potassium
K deficiencies sometimes show on indoor plants even when there is apparently 
enough supplied for normal growth. Often, potassium-deficient plants are the 
tallest ((Potassium is associated with apical dominance in some plant species.)) 
and appear to be the most vigorous. Starting on the large lower leaves, the tips 
of the blades brown and die. Necrotic areas or spots form on the blades, 
particularly along the margins. Sometimes the leaves are spattered with 
chlorotic tissue before necrosis develops, and the leaves look pale or yellow. 
Symptoms may appear on indoor plants grown in a soil rich in organic material. 
This may be due to high salinity (Na) of some manures or composts used in the 
soil. Red stems and petioles accompany potassium deficiencies. K deficiencies 
that could seriously affect your crop rarely occur with indoor soils. However, 
mild symptoms are quite common. Usually the plants grow very well except for 
some necrotic spotting or areas on the older leaves. (This condition is 
primarily and aesthetic problem, and you may choose not to fertilise. See 19.3.) 

K deficiencies can be treated with any fertiliser that contains potassium. Wood 
ashes dissolved in water are a handy source of potassium. Recovery is slow. New 
growth will not have the red colour, and leaves will stop spotting after a 
couple of weeks. In a K-deficient soil, much of the added potassium is absorbed 
by the soil until a chemical balance is reached. Then additional potassium 
becomes readily available to the plant. 
Calcium
Ca deficiencies are rare and do not occur if you have added any lime compound or 
wood ash. But calcium is added primarily to regulate soil chemistry and pH. Make 
sure that you add lime to soil mixtures when adding manures, cottonseed meal, or 
other acidic bulk fertilisers. An excess of acidic soil additives may create 
magnesium or iron deficiencies, or very slow, stunted growth. Remedy by adding 
one teaspoon of dolomitic lime per quart of water until the plants show marked 
improvement. Periodically fertilise with a complete fertiliser. Foliar feeding 
is most beneficial until the soil's chemistry reaches a new balance. 
Sulfur
S is plentiful in both organic and mineral soils. Liming and good aeration 
increases S availability. Hence S deficiencies should not occur in soils that 
are suitable for growing marijuana. However, sulfur deficiencies sometimes can 
be confused with N deficiencies and may also occur because of an excess of other 
nutrients in the soil solution. Sulfur-deficiency symptoms usually start at the 
top of the plant. There is a general yellowing of the new leaves. In pots, the 
whole plant may lose some green colour. Both sulfur and Mg deficiencies can be 
treated with the same compound, epsom salts (MgSO4). Epsom salts, or bathing 
salts are inexpensive and available at drug stores. 
Magnesium
Mg deficiencies are fairly common. They frequently occur in Soilless mixtures, 
since many otherwise all-purpose fertilisers do not contain Mg. Magnesium 
deficiencies also occur in mixtures that contain very large amounts of Ca or Cl. 
Symptoms of Mg deficiency occur first on the lower leaves. There is chlorosis of 
tissue between the veins, which remain green, and starting from the tips the 
blades die and usually curl upward. Purple colour builds up on stems and 
petioles. 
A plant in a pot may lose much of its colour in a matter of weeks. You may first 
notice Mg symptoms at the top of the plant. The leaves in the growing shoot are 
lime-coloured. In extreme cases, all the leaves turn practically white, with 
green veins. Iron deficiency looks much the same, but a sure indication of Mg 
deficiency is that a good portion of the leaf blades die and curl. Treat Mg 
symptoms with one-half teaspoon of epsom salts to each quart of water, and water 
as usual. The top leaves recover their green colour within four days, and all 
but the most damaged should recover gradually. Continue to fertilise with epsom 
salts as needed until the plants are flowering well. If you are using soilless 
mixtures, include epsom salts regularly with the complete mixture. Because Mg 
deficiencies may indicate interference from other nutrients, foliar-spray with 
Mg to check your diagnosis if the plants are not obviously recovering. 
Iron
Fe deficiency rarely occurs with indoor mixtures. Iron is naturally plentiful in 
most soils, and is most likely to be deficient when the soil is very acid or 
alkaline. Under these conditions, which sometimes occur in moist eastern soil 
outdoors, the iron becomes insoluble. Remedies include adjusting the Ph before 
planting; addition of rusty water; or driving a nail into the stem. Commercial 
Fe preparations are also available. If the soil is acidic, use chelated iron, 
which is available to the plants under acidic conditions. 
Symptoms of iron deficiency are usually distinct. Symptoms appear first on the 
new growing shoots. The leaves are chlorotic between the veins, which remain 
dark green and stand out as a green network. To distinguish between Mg and Fe 
deficiencies, check the lower leaves for symptoms. Iron symptoms are usually 
most prominent on the growing shoots. Mg deficiencies will also show in the 
lower leaves. If many of the lower leaves have been spotting or dying, the 
deficiency is probably Mg. Mg deficiencies are much more common than iron 
deficiencies in marijuana. 
Other Trace Elements
The following deficiencies are quite rare. Trace elements are needed in 
extremely small amounts, and often enough of them are present as impurities in 
fertilisers and water to allow normal growth. Many houseplant fertilisers 
contain trace elements. Trace-element deficiencies are more often caused by an 
extreme pH than by inadequate quantities in the soil. If a deficiency is 
suspected, foliar-spray with the trace element to remedy deficiencies. Our 
experience has been that trace-element deficiencies rarely occur indoors. We 
advise you not to add trace elements to indoor soils, which usually contain 
large amounts of trace elements already because of the addition of organic 
matter and liming compounds. It is easy to create toxic conditions by adding 
trace elements. Manufacturers also recommend using amounts of trace elements 
that may be too high for indoor gardens; so use them at about one-fourth of the 
manufacturer's recommended dose if an addition is found to be necessary. 
Manganese
Mn deficiency appears as chlorotic and the necrotic spots of leaf tissue between 
the veins. They generally appear on the younger leaves, although spots may 
appear over the whole plant. Manganese deficiencies are not common. Manganese is 
present in many all-purpose fertilisers. Mn deficiencies may occur if large 
amounts of Mg are present. 
Boron 
B deficiency may occasionally occur in outdoor soils. The symptoms appear first 
at the growing shoots, which die and turn brown or grey. The shoots may appear 
"burned," and if the condition occurs indoors, you might think the lights have 
burned the plant. A sure sign of boron deficiency is that, once the growing tip 
dies, the lateral buds will start to grow but will also die. B deficiency can be 
corrected by application of boric acid, which is sold as an eyewash in any 
drugstore. Use one-fourth teaspoon per quart of water. Recovery occurs in a few 
days with healthy growth of new shoots. 
Molybdenum
Mb deficiency occurs in outdoor soils, but rarely indoors. Mb is readily 
available at neutral or alkaline pH. Mb is essential for nitrogen metabolism in 
the plant, and symptoms can be masked for a while when N fertilisers are being 
used. Usually there is a yellowing of the leaves at the middle of the plant. 
Fertilising with nitrogen may remedy some of the yellowing. However, Mb symptoms 
generally progress to the growing shoots and new leaves often are distorted or 
twisted. Mb is included in many all-purpose fertilisers. 
Zinc
Zn-deficiency symptoms include chlorosis of leaf tissue between the veins. 
Chlorosis or white areas start at the leaf margins and tips. More definite 
symptoms are very small, new leaves which may also be twisted or curled 
radially. Zn deficiencies may occur in alkaline western soils. Galvanised nails 
can be buried or pushed into the stem. Commercial preparations of zinc are also 
available. 
Copper
Cu deficiencies are rare; be careful not to confuse their symptoms with the 
symptoms of overfertilisation. The symptoms appear first on the younger leaves, 
which become necrotic at the tips and margins. Leaves will appear somewhat limp, 
and in extreme cases the whole plant will wilt. Treat by foliar-spraying with a 
commercial fungicide such as CuSO4. 
9.5 Soilless Mixtures
Soilless mixtures are an alternative to using large quantities of soil. Their 
main advantage is complete control over the nutrients that your plants receive. 
Soilless mixtures are also inexpensive and easy to prepare. They have a 
near-neutral pH and require no pH adjustment. 
Soilless mixtures are made from soil components such as vermiculite, sand, or 
perlite. Soilless mixtures should be blended in such a way that they hold 
adequate water, but also drain well and do not become soggy. A good general 
formula is two parts vermiculite to one part perlite. About 10 percent coarse 
sand or gravel can be added to give weight and stability to the pots. Instead of 
vermiculite, you can use Jiffy-Mix, Metro-Mix, Ortho-Mix, Pro-Mix and other 
commercial soilless mixtures, which are fortified with a small amount of 
necessary nutrients, including trace elements. You can also substitute coarse 
sand for perlite. 
Potting
It is best to use solid containers with soilless mixtures rather than plastic 
bags. Grow the plants in one- to three-gallon containers. There won't be much 
difference in the size of the plants in one-gallon or in three-gallon sizes, but 
you will have to water a large plant every day in a one-gallon container. (The 
plants can always by transplanted to a larger container.) The pots must have 
drainage holes punched in the bottoms. Pot as usual, and add one tablespoon of 
dolomitic lime or two tablespoons of wood ash to each gallon of mixture. 
Germinating
Plants may have problems germinating in soilless mixtures. The top layer of 
mixture often dries rapidly, and sprouts may die or not germinate. Young 
seedlings also seem to have difficulty absorbing certain nutrients (notably 
potassium), even though adequate amounts of nutrients are being added. Since 
this difficulty may retard growth, it is best to start the plants in small pots 
with soil. Use eight-ounce paper cups, tin cans, or quart milk containers cut in 
half. Mix three parts topsoil or potting soil to one part soilless mixture. Fill 
the starting pots and germinate as usual. When the plants are two to three weeks 
old, transplant to the soilless mixture. First moisten the soil, and then remove 
the soil as intact as possible. You might handle the transplant like making 
castles, by carefully sliding the moist soil out of the pot. Or you can cut away 
the sides of the container while you place the transplant in the soilless 
mixture. When watering, make sure you water around the stem to encourage roots 
to grow into the soilless mixture. 
Peat pellets that expand are also good for starting seedling. Plant several 
seeds in each pellet, and place it in the soilless mixture after the sprouts 
appear. 
Fertilising
Soilless mixtures can be treated with a trace-element solution. We have grown 
crops with no special addition of trace elements, and the plants completed their 
lives without showing symptoms of trace-element deficiency. In these cases there 
were apparently enough trace elements in the lime and the fertilisers that were 
used to provide the major nutrients. Many all-purpose fertilisers also contain 
trace elements. However, it is a good idea to treat soilless mixtures with a 
mild solution of trace elements before planting. Large plants can be treated a 
second time during the third or fourth month of growth. Do not use trace 
elements more often unless plants show definite trace-element deficiencies. 
Iron is the only trace element that is needed in more than minute quantities. 
Iron can be supplied by mixing a few brads or nails into the soilless mixture. 
Use any soluble fertiliser that is complete, that is, that contains some of each 
of the major nutrients. Choose one with a formula that is highest in N but 
contains a good portion of both P and K. For example, Rapid-Gro is 23-19-17 and 
works well for soilless mixtures. 
Table 18 gives a formula that has worked well for us. The figures in it are a 
guide for estimating the amounts of fertiliser to use. When choosing a 
fertiliser by means of this chart, use N for a guide. For example, suppose the 
only fertiliser you can find that has good proportions of the major nutrients as 
a 20-15-15. Divide 5 (the figure for N in the table) by 20 (the figure for N in 
the fertiliser), and get the result 1/4. That is, the fertiliser if four times 
as concentrated in N as you need; so you would use one-fourth the amount of 
fertiliser shown in Table 18. For instance, during the vegetative stage, you 
would give the plants one-half to three-fourths of a level teaspoon of 
fertiliser per gallon of water each time you water. 

Table 18 - Guidelines for Fertilizing Soilless Mixtures 

Growth Stage  N        P2O5     K20      Amount
Seedling      5        3        4        1.5 to 2 tsp/gal
Vegetative    5        2        3        2 to 3 tsp/gal
Flowering     5        5        3        0.5 tp 1.5 tsp/gal
It is also not necessary to fertilise in these ratios. You could use a 10-10-10 
fertiliser throughout growth; you would use half the amounts listed in Table 18. 
The most important point is that the plant receive enough of each element, not 
that they receive specific proportions. 
Fertilising according to volume of fertiliser is not very accurate, and also 
does not take into account other variables (such as variety, light, temperature, 
etc.) that determine the amounts of nutrients your plants can use. However, it 
is a simple and useful way of estimating the plant's needs. You can more 
accurately gauge the plants' needs by giving a sample plant twice the 
concentration of fertiliser, and another half the concentration. Their 
performance will give you an idea of whether you are using too much or too 
little fertiliser. Too much fertiliser is the most damaging condition; so when 
in doubt give the plants less rather then more. Do not continue to give the 
plants the recommended amounts of fertiliser if the sample plant that is 
receiving less nutrients is growing as well as the other plants. 
Another way of monitoring the plant's growth is to grow a few plants in a 
standard soil mixture. This will show you whether the plants in the soilless 
mixture are growing as fast as they should, and will give you a reference for 
diagnosing deficiencies. 
Besides providing N, P, K, and the trace elements, you must also give your 
plants secondary nutrients. Ca is added by mixing a tablespoon of lime or two 
tablespoons of wood ash when preparing the soilless mixture. (Calcium is usually 
present in water and in many fertilisers as part of the salts that contain 
nutrients, for example, Ca(NO3)2.) Magnesium and sulfur are both found in common 
epsom salts, MgSO4. Use one-eighth teaspoon of epsom salts to each teaspoon of 5 
percent N. For example, if you are using a 20 percent N fertiliser, you would 
use half a teaspoon of MgSO4 to each teaspoon of fertiliser. (Actually, enough 
sulfur is often present, either as part of the soilless mixture or as part of 
nutrient salts to allow growth.) Magnesium can also be supplied by using 
dolomitic limestone. 
Soilless mixtures are something between soil mixtures and water cultures 
(hydroponics). With hydroponics, the plants are grown in a tank of water. The 
fertilisers are added in solution, and the water solution is periodically 
circulated by a pump. 
Another variation on soilless mixtures is to add a small amount of soil or humus 
to the soilless mixture. Some examples are: 
        1. 4 parts soilless mixture to 1 part soil;
	2. 8 parts soilless mixture to 1 part humus;
	3. 15 parts soilless mixture to 1 part limed manure.
             
Overfertilising is less a problem with soilless mixtures then with soil, because 
of higher concentrations of salts are tolerable in soilless mixtures and because 
excess salts are easily flushed out of the mixture. A good idea is to flush each 
pot once after two months of growth, again after four months. Any time the 
plants show symptoms of overfertilisation, leach the pots immediately. Flood 
each pot with plain water so that it runs out the drainage holes. Continue 
flooding the pots until a couple of gallons of water have run through the pot. 
Don't fertilise for at least a week. Then fertilise with a more dilute solution 
that was used before. {Figure 51a. Over fertilisation. Leaves turn bright gold 
and die, starting at the top of the plant.} 
Chapter Ten
DISEASES AND PLANT PESTS
Plants are considered diseased when their health or development is impaired 
enough that the adverse effects become visible to the eye. Disease may be caused 
by infectious microbes, such as bacteria or viruses, by pests such as insects, 
or by nutritional deficiencies or imbalances. However, for diseases that might 
affect your plants, there should be no need for a plant doctor. You'll be able 
to diagnose the symptoms after careful observation. 
Leaves naturally drop from plants during the course of their lives. Not every 
leaf will develop perfectly or so. The small leaves that are formed during the 
first few weeks of growth normally die within three months. Leaves at the bottom 
of healthy plants often die because they are shielded by the upper instance, in 
a garden receiving only 80 watts of fluorescent light, the plants may stay green 
only up to three or four feet away from the lights. Lower leaves may turn pale 
and yellow and then dry to gold or rust colours. 
10.2 Microbial Diseases
Because Cannabis is not native to the Americas, most of the microbial diseases 
that attack the plant are not found in this country. Homegrown Cannabis is 
remarkably free of diseases caused by microbes, and there is little chance of 
your plants suffering from these diseases. Fungal stem and root rots seem to be 
the only ones of consequence. These occur only because of improper care. 
Watering too often, coupled with a stagnant, humid atmosphere, encourages stem 
rot to develop. Stem rot appears as a brown or black discolouration at the base 
of the stem and is soft or mushy to the touch. Allow the soil to dry between 
waterings, and be sure to water around the stem, not on it. Wipe as much of the 
fungus and soft tissue away as possibly. If the rot doesn't disappear in a few 
weeks, treat it with a fungicide. 
10.3 Nutrient Diseases
Diseases due to nutrient deficiencies (see section 9), are common indoors, and 
their symptoms usually worsen with time, affecting more and more of the plant. 
Whole leaves may be pale, or turn yellow or white; the condition may first 
afflict the bottom, or top, or the entire plant at once. Deficiency symptoms 
often appear as spots, splotches, or areas or chlorotic (lacking green) tissue. 
Sometimes necrotic (dead) tissue appears that is copper, brown, or gray. 
However, before you search to section 9, carefully inspect the plants for any 
signs of plant pests. 
10.4 Plant Pests
The indoor garden is an artificial habitat where the plants live in isolation 
from the natural world. For this reason, few of you will have any problems with 
plant pests. However, indoor plants are particularly susceptible to pests once 
contaminated. In nature, the pest populations are kept in check by their natural 
enemies, as well as by wind, rain, and changing temperatures. Without these 
natural checks, pests can run rampant through the indoor garden. 
The most common and destructive pests are spider mites and whiteflies. Spider 
mites are barely visible to the naked eye; they are ovoid-shaped. Juvenile mites 
are transparent and change to green as they suck the plant's tissue. Adults are 
tan, black, or semitransparent. False spider mites are bright red. Mites are 
usually well-established before you discover them, because they are so difficult 
to see. 
Whiteflies are white (obviously) but look like tiny moths rather than flies. The 
adults are about 1/16 inch long, and you may not see one unless if flutters by 
the corner of your eye. Then shake the plants. If the result looks like a small 
snowstorm, the plants are infested with whiteflies. {Figure 52. Left: Spider 
mite (x16). Right: A match head dwarfs tiny spider mites.} 
The symptoms of infection by mites and whiteflies are similar. Symptoms usually 
appear on the lower leaves and gradually spread to the top of the plant. The 
first indications are that the plant loses vigour; lower leaves droop and may 
look pale. Look closely at the upper surfaces of the leaves for a white 
speckling against the green background. The speckles are due to the pests 
sucking the plant's chlorophyll-rich tissue. With time, the leaf loses all 
colour and dies. 
Pests are easiest to find on the leaves that are beginning to show some damage. 
You can usually see mites and whitefly larvae as tiny dots looking up at the 
lights through the undersides of the leaves. 
To find out which pest you have, remove some damaged leaves and inspect the 
undersides under bright daylight. With spider mites, if you discover them early, 
a leaf may show only one or two tiny dots (adults) and a sprinkling of white 
powder (eggs) along the veins. In advanced cases, the undersides look dusty with 
the spider mites' webbing, or there may be webbing at the leaf nodes or where 
the leaflets meet the petioles. With whiteflies, you usually see the adults 
first. On the undersides of the leaves the whitefly larvae look like mites, but 
there is no webbing, and there are tiny golden droplets of "honeydew" excreted 
by the adult whiteflies. {Figure 53. Mites appear as black specks when you look 
up to the lights from the undersides of the leaves. Also see Plate 14.} 
Take quick action once you discover plant pests. If the plants are less than a 
month old, you will probably be better off to clean out the garden, in order to 
eliminate the source of the pests, and start over. As long as the plants are 
healthy they can withstand most attacks. The more mature the plants are, the 
less they are affected by pests. Whiteflies and mites sometimes disappear from 
flowering plants, particularly the female flowers. Mites are difficult to 
eliminate completely. Often a holding action will save a good crop. 
If only a few plants in your garden are infected, remove them. Or else, remove 
any leaves that show damage. If the plants are three or more months old, you 
might consider forcing them to flower while they are still healthy. Plants that 
are good-sized and still vigorous will usually stand up well to mites once they 
are flowering. 
If you don't want to use insecticides, there are several alternative ways to 
keep the pests in check until flowering. Mix 1/8 to 1/4 pound of pure soap (such 
as Ivory flakes) thoroughly in one gallon of lukewarm water. Then cover each pot 
with foil or newspaper, invert it, and dip and swish the plant around several 
times in the soapy solution. Let is drip dry and rinse with clear water. Use the 
dunking procedure every week or two until the plants are larger. This is often 
enough to get the plants growing well and into flowering before the pest 
population can become a serious problem. 
Two homemade sprays that can be effective are dormant oil sprays ((See "Insects 
and Pests" in the Outdoor Section.)) and hot pepper sprays. 
To make hot pepper spray, mix four hot peppers with one medium onion and on 
clove garlic (213). Grind or chop and mash them along with some water. Cover the 
mash with water and allow it so stand a day or two. Add enough water to make two 
quarts. Strain through a coffee filter or paper towels in a funnel. Add one-half 
teaspoon of detergent and spray as you would an insecticide. 
No one wants to use insecticides; yet they seem to be the only way to eliminate 
mites. There are a number of insecticides on the market that are relatively 
safe. Insecticides such as pyrethrum, rotenon, and malathion are relatively 
non-toxic to warm-blooded animals when used as directed. These are effective 
against many different plant pests besides mites and whiteflies. Additionally, 
they break down into harmless compounds such as carbon dioxide and water in a 
matter of days; so they do not persist in the environment. 
Safe insecticides are used for vegetables. Follow all the package precautions. 
Do not use more, or more often, than recommended. Overuse can kill the plant. 
The label will list the number of days to wait before you can safely ingest the 
plant, usually from two to 35 days after spraying. 
Both mites and whiteflies generally complete their brief life cycles in about 
one to two weeks. Because sprays are not effective against the eggs, repeat the 
spraying about once a week for three successive weeks to completely eliminate 
the pests. Since their generations are short-lived, some pests may become 
resistant to the spray. This can be a problem with whiteflies. Try a different 
insecticide if the first one does not seem to be working. 
Add a couple of drops of liquid detergent to each quart of insecticide solution. 
Detergent acts as a wetting agent and helps the insecticide to contact the pests 
and stick to the plant. Small plants can be dunked directly in the solution, the 
surest way to kill pests. 
To spray the plants, start at the back of the garden so that you are working 
away from the plants already sprayed. Spray the entire plant and soil surfaces, 
paying special attention to the undersides of the leaves where pests tent to 
congregate. Stay out of the garden and keep the room closed that day. 
Sulfur dusts can also be effective against mites and many other pests, and are 
safe to use. The easiest way to apply them is with a plastic "squeeze" bottle 
which has a tapered top. Make sure you dust the underside of the leaves. 
Before using any insecticide, remove all damaged leaves. Do not use any 
insecticide during flowering. Rinse the plant with a clear water spray about one 
week after applying any insecticide, and once more before you harvest. Otherwise 
there may be residues left which will affect the taste of the grass. 
There are several other pests that can be a problem, although they rarely 
seriously affect marijuana. Aphids are about 1/16 inch long and are black, 
green, red, or pink. They have roundish bodies with long legs and antennae. Some 
species have wings. They congregate on the undersides of leaves which may then 
lose colour and become curled or distorted. Aphids excrete honey-dew droplets on 
the undersides of the leaves which can attract ants. If ants are also present, 
set out ant traps, because the ants will spread the aphids to other plants. A 
few successive washings in soapy water or one or two sprayings of the 
insecticides mentioned above should eliminate aphids. 
Mealy bugs are white, about 3/16 of an inch long, and look like small, flat 
sowbugs. They don't seem to like marijuana and avoid it of other plants are 
present. Mealy bugs can be removed individually with cotton swabs and alcohol. 
Gnats are attracted to moist soil that is rich in partially decayed organic 
matter such as manures. To discourage gnats when using manures, cover the top 
few inches in the pot with the soil mixture and no manure. Drench the soil with 
malathion solution for gnats or any other soil pest. Flypaper will also help 
against gnats as well as whiteflies. 
Some people don't mind having a few pests on their plants. Whether you want to 
eliminate the pests completely or simply keep them in check may come down to 
whether you mind hearing the snap, crackle, and poop as their little bug bodies 
heat and explode when the harvest is smoked. Commercial marijuana, or any 
marijuana grown outdoors, will contain innumerable bugs and other small 
lifeforms. 
Prevention
Whiteflies and spider mites are extremely contagious. Mites can be carried to 
the plant on hands, clothing, or an animal's fur. Many houseplant pests can fly 
or float to the garden through open windows. Mites crawl through cracks in walls 
and foundations during autumn, seeking warmth. 
Many houseplants are popular because they can withstand abuse and infections by 
common plant pests. Your houseplants may harbor mites for years without your 
knowledge. You can find out if your houseplants have mites by placing some 
marijuana seedlings among the houseplants. Mites seem to enjoy young marijuana 
plants so much that the plants show symptoms of mites in a matter of weeks of 
any are nearby. 
Hopefully, you'll never have to deal with pests. Prevention is the best policy. 
Use soil that has been pasteurised or sterilised to avoid bringing pest eggs and 
larvae into the garden. Keep the garden isolated from other plants. Use separate 
tools for the marijuana garden and for other plants. Screen windows in the 
garden with wire screen or mesh fabrics such as nylon. 



Chapter 11
MAINTENANCE AND RESTARTING
To start a new crop, it is best to begin with a fresh soil. This is especially 
true if the plants were in small pots or were root-bound. 
If you have fertilised regularly, the soil may contain near-toxic amounts of 
salts. Most of the salts build up in the top two-inch layer of soil. To salvage 
large quantities of soil, discard the top three-inch layer of soil from each 
pot. Add fresh soil and bulk fertilisers. Thoroughly mix and repot in clean 
containers. 
It is generally not advisable to use the same soil for more than two crops. 
Although the used soil may not support healthy growth for potted plants, it is 
an excellent addition to any garden soil. Spread the soil as you would a mulch. 
The salt concentration is quickly diluted and benefits, rather than harms, 
garden soil. 
Periodically clean the tubes and reflectors to remove dust and grime. As with 
windows, this dirt substantially decreases the amount of light the plants 
receive. Fluorescents lose approximately 20 to 40 percent of their original 
output within a year's use. Generally the higher-wattage tubes decline more 
rapidly than standard-output tubes. Vita-lite tubes last the longest, followed 
by standard fluorescents. Gro-tubes are the shortest-lived, and most growers 
replace them after two crops. Older tubes can be used to start seedlings and 
during the first month of growth. Since the plants are small and the light 
system is low, the old tubes generate enough light for healthy growth. Replace 
incandescent bulbs after 500 light hours. 
 
PART 3: OUTDOOR 



CULTIVATION
Chapter 12
CHOOSING A SITE
There are several factors to consider when deciding where to plant, including 
sunlight, microclimate, availability of water, and condition of the soil. But 
the garden's security should be your first consideration. No matter what size 
your garden, rip-offs and confiscation are constant threats. But these risks can 
be minimised by careful planning and common senses. 
In some countries, law-enforcement agencies take a tolerant attitude toward 
small gardens, and people grow Cannabis in their backyards. In other areas, 
police are not as enlightened and place an emphasis on cultivation busts. In 
either case, the larger the garden, the greater the potential danger. {Figure 
55. A Nassau Country police officer stands in a field of marijuana plants in 
Lattingtown, Long Island.} 
In Hawaii and California, where marijuana growing has become a booming business, 
helicopters have been a problem for commercial growers. Aircraft outfitted with 
visual or infrared equipment, dogs, and finks have all been used to seek out 
illicit plots. Aircraft equipment is least effective on steep slopes and where 
the vegetation is lush and varied. Where aircraft are a problem, growers prune 
marijuana to obscure its distinctive shape. The plants are difficult to detect 
from a distance when intercropped with bamboo, sunflowers, sugar cane, soybeans, 
or tall weeds (see Figure 60). Commercial growers often plant several small 
dispersed stands or many single plants, which are more difficult to detect and 
serve as insurance against total loss. 
But rip-offs rather than the law are more of a problem for marijuana growers. 
From every section of the United States, reports confirm that marijuana theft 
has reached epidemic proportions, and even well-hidden plant fall prey to 
unscrupulous people. These lowlifes often search near hippie communities and 
popular planting areas. Their best ally is a loose lip; so keep your garden on a 
"need to know" basis. 
12.2 Where to Grow
Given the value of marijuana, many people think they'll grow an acre or two. But 
it is much harder to find spots suitable for large-scale farming than to find 
small garden plots. Large gardens require more planning and commitment, and 
usually a remote area. They may need a lot more time, energy, and investment in 
materials and labor-saving machinery than smaller gardens. 
A small but well-cultivated garden, say, ten by ten feet, can yield over four 
pounds of grass each crop. By planning realistically, you'll harvest a good 
stash of potent grass rather than a lot of disappointment. 
Moat people who grow marijuana plant it in their backyards. They hide the plants 
from curious neighbours and passers-by with walls, fences, arbor, or similar 
enclosures. Some people plant Cannabis as part of their vegetables garden, 
pruning the plants to make them less conspicuous. 
Gardeners often use ingenious ideas to keep their gardens secret. A woman on 
Long Island grows over thirty large plants in containers in her drained swimming 
pool. Although some of the plants reach a height of 12 feet, they can't be seen 
over the enclosing fence. 
A couple living near Nashville, Tennessee, took the roof off their three-car 
garage and painted the walls white to create a high-walled garden. Other growers 
use sheds with translucent roofs. 
Guerilla Farming
Many growers feel safer planting away from their property. Should the garden be 
discovered, they are not in jeopardy. On the negative side, they usually lose 
the close contact and control that a home gardener has. 
Urban gardeners use makeshift greenhouses, rooftops, vacant lots, and city 
dumps. Vacant lost that are overgrown with lush weeds can support a good crop, 
if the marijuana plants get a head start on the indigenous weeds. 
Fields, forest clearings, railroad rights-of-way, stream banks, runoff and 
irrigation ditches, clearings beneath high-tension lines, deserted farms and 
quarries, overgrown fields, and abandoned houses have all been used as garden 
spots. In areas where hemp is a problem weed, people plant seeds from 
high-potency marijuana in the same fields where the weedy hemp grows. Growers 
harvest the plants in late July before they flower and before the fields are 
watched or destroyed by law enforcers. 
Larger growers often look for rough, unpopulated terrain that is accessible only 
by plane, helicopter, four-wheel-drive vehicles, or long hikes. They avoid areas 
which hunters and hikers are likely to use before harvest. 
Serious growers often find unusual places to start gardens. A grow in Chico, 
California, hacks through two hundred yards of dense underbrush and bramble to 
reach his clearing. In Oregon some growers maintain fields which are a gruelling 
eight-hour uphill hike from the nearest road. Some Florida farmers commute to 
their island and peninsula gardens by boats. A master gardener in Colorado 
lowers himself by rope to a fertile plain 50 feet below a cliff. 
A farmer in Hawaii wrote, "The main concern is to grow in an undetectable place 
where the plants can still get enough sun. This is becoming very difficult to 
find and some very elaborate subterfuges have been developed. People on Maui are 
growing plants suspended from trees and on tree platforms! Around here some 
people carry small plants in buckets far out on the lava fields where there is a 
light shading from Ohia trees and you don't leave tracks. Also people go into 
the sugarcane fields, tear out some cane, and put in their plants. I am sure 
many other things are being done." 
12.3 Light
Marijuana is a sun plant. The plants will grow in partially shaded areas, but 
about five hours of direct sunlight are needed for development into a lush bush. 
Marijuana does best when it has direct sunlight all day. If it grows at all in a 
heavily shaded area, it will be dwarfed and sparse - a shadow of its potential. 
Try to choose a place that maximises light. Flat areas get the most sunlight, 
but many growers prefer to use slops and hillsides which help to hide the 
plants. Southern slops usually receive more sun and stronger light than eastern 
and western slops, which are shaded in the afternoon and morning, respectively. 
Northern slopes are rarely used, since they get the least sunlight and are also 
the coldest. Steeper slops are shaded sooner than gradual slopes, and lower 
areas are shaded earlier than high ones. 
Sunlight at high altitudes is more intense, because of the thinner atmosphere 
and the usually lower pollution. The atmosphere and pollutants at lower 
elevations absorb and scatter some of the solar radiation. 
Backyard gardeners usually compromise between the need for maximum light and the 
need for subterfuge. An area that gets several hours of direct sunlight and 
bright unobstructed daylight for the rest of the day will do well. A garden 
exposed to the south usually gets the strongest light and is the warmest. 
Overhanging vegetation should be pruned so that the plants are shaded as little 
as possible. 
Most marijuana strains are acclimated to tropical and semitropical latitudes, 
where the daytime is relatively short (10 to 14 hours, depending on season), but 
the sunlight is quite strong. At latitudes in the United States, the sun is not 
as intense (although in the summer the difference is small), but the days are 
longer, and the plants can grow extremely fast. It is not true that intense 
sunlight is needed to grow great marijuana. However, a summer characterised by 
clear sunny weather will usually produce a larger and slightly more potent crop 
than if the season is cloudy and rainy. 
Sunlight can be maximised by adequate spacing and orientation of the garden. 
This is covered in section 14. 
Chapter 13
SOIL
Of all the factors involved in growing plants, soil is the most complex. It has 
its own ecology, which can be modified, enriched, or destroyed; the treatment it 
receives can ensure crop success or failure. 
There is no such thing as the perfect soil for Cannabis. Each variety can grow 
within a wide range of soil conditions. Your goal is garden soil within the 
range for healthy growth: well-drained, high in available nutrients, and with a 
near neutral (7.0) pH. Cannabis grows poorly, if at all, in soils which are 
extremely compacted, have poor drainage, and low in fertility, or have an 
extreme pH. 
There are several soil factors that are important to a grower; these include 
soil type, texture, pH, and nutrient content. We will begin this chapter by 
discussing each of these topics in succession, and will then turn to discussion 
of fertilisers, soil-preparation techniques, and guerilla farming methods. 
13.2 Types of Soil
Each soil has its own unique properties. These properties determine how the soil 
and plants will interact. For our purposes, all soils can be classified as 
sands, silts, clays, mucks, and loams. Actually, soils are usually a combination 
of these ingredients. If you look carefully at a handful of soil, you may notice 
sand granules, pieces of organic matter, bits of clay, and fine silty material. 
Sandy Soils
Sands are formed from ground or weathered rocks such as limestone, quartz, 
granite, and shale. Sandy soils may drain too well. Consequently, they may have 
trouble holding moisture and nutrients, which leach away with heavy rain or 
watering. Some sandy soils are fertile because they contain significant amounts 
(up to two percent of organic matter, which also aids their water-holding 
capacity. Sandy soils are rich in potassium (K), magnesium (Mg), and trace 
elements, but are often too low in phosphorous (P) and especially nitrogen (N). 
N, which is the most soluble of the elements, is quickly leached from sandy 
soil. Vegetation on sands which is pale, yellowed, stunted, or scrawny indicates 
low nutrients, usually low N. 
Sandy soils can be prepared for cultivation without much trouble. They must be 
cleared of ground cover and treated with humus, manure, or other N-containing 
fertilisers. In dry areas, or areas with a low water table, organic matter may 
be worked into the soil to increase water-holding capacity as well as fertility. 
Sandy soil does not usually have to be turned or tilled. Roots can penetrate it 
easily, and only the planting row need be hoed immediately before planting. 
Growers can fertilise with water-soluble mixes and treat sandy soil almost like 
a hydroponic medium. 
Sandy soils are also good candidates for a system of sheet composting (spreading 
layers of uncomposted vegetative matter over the garden), which allows nutrients 
to gradually leach into the soil layers. Sheet composting also prevents 
evaporation of soil water, since it functions as a mulch. 
Silts
Silts are soils composed of minerals (usually quartz) and fine organic 
particles. To the casual eye, they look like a mucky clay when wet, and resemble 
dark sand or brittle clods when dry. They are the result of alluvial flooding, 
that is, are deposits from flooding rivers and lakes. Alluvial soils are usually 
found in the Midwest, in valleys, and along river plains. The Mississippi Delta 
is a fertile alluvial plain. 
Silts hold moisture but drain well, are easy to work when moist, and are 
considered among the most fertile soils. They are frequently irrigated to extend 
the length of the growing season. Unless they have been depleted by faulty 
farming techniques, silts are rich in most nutrients. They often support 
healthy, vigorous vegetation. This indicates a good supply of N. 
Mucks
Mucks are formed in areas with ample rainfall which supports dense vegetation. 
They are often very fertile, but may be quite acidic. They usually contain 
little potassium. 
Mucks range from very dense to light sandy soils. The denser ones may need heavy 
tilling to ensure healthy root development, but the lighter ones may be cleared 
and planted in mounds. Mucks can support dense vegetation, and are often turned 
over so that the weeds thus destroyed form a green manure. 
Clay Soils
Clays are composed of fine crystalline particles which have been formed by 
chemical reactions between minerals. Clays are sticky when wet, and can be 
moulded or shaped. When dry, they form hard clods or a pattern of square cracks 
along the surface of the ground. Clays are usually hard to work and drain 
poorly. Marijuana roots have a hard time penetrating clay soils unless these 
soils are well-tilled to loosen them up. Additions of perlite, sand, compost, 
gypsum, manure, and fresh clippings help to keep the soil loose. Clay soils in 
low-lying areas, such as stream banks, may retain too much water, which will 
make the plants susceptible to root and stem rots. To prevent this, some growers 
construct mounds about six inches to one foot high, so that the stems and tap 
roots remain relatively dry. 
Clay soils are often very fertile. How well marijuana does in clay soils usually 
depends on how well these soils drain. In certain areas "clay" soils regularly 
support corn cotton. This type of soil will support a good crop of marijuana. 
Red colour in clay soil (red dirt) indicates good aeration and a "loose" soil 
that drains well. Blue or gray clays have poor aeration and must be loosened in 
order to support healthy growth. 
A typical schedule for preparing a heavy clay soil In the late fall, before 
frost, turn soil, adding fresh soil conditioners, such as leaves, grass 
clippings, fresh manure, or tankage. Gypsum may also be added to loosen the 
soil. Spread a ground cover, such as clover, vetch, or rye. In early spring, 
making sure to break up the large clods, and add composts and sand if needed. At 
planting time, till with a hoe where the seeds are to be planted. 
As the composts and green manure raise the organic level in the soil, it becomes 
less dense. Each year, the soil is easier to work and easier for the roots to 
penetrate. After a few years, you may find that you only need to turn under the 
cover crop. No other tilling will be needed. 
Loams
Loams are a combination of about 40 percent each of sand and silt, and about 20 
percent clay. Organic loams have at least 20 percent organic matter. In 
actuality, a soil is almost always a combination of these components, and is 
described in terms of that combination, e.g., sandy silt, silty clay, sandy 
clay, or organic silty clay. Loams range from easily worked fertile soils to 
densely packed sod. Loams with large amounts of organic matter can support a 
good marijuana crop with little modification. 
13.3 Humus and Composts
Humus and composts are composed of decayed organic matter, such as plants, 
animal droppings, and microbes. Their nutrient contents vary according to their 
original ingredients, but they most certainly contain fungi and other 
microorganisms, insects, worms, and other life forms essential for the full 
conversion of nutrients. As part of their life processes, these organisms take 
insoluble chemicals and convert them to soluble forms, which plant roots can 
then absorb. Humus and composts hold water well and are often added to condition 
the soil. This conditioning results from the aerating properties and 
water-holding capacity of humus and composts, as well as balanced fertility. 
Humus and composts have a rich, earthy small, look dark brown to black, and may 
contain partially decayed matter, such as twigs or leaves. They are produced 
naturally as part of the soil's life process or can be "manufactured" at the 
site by gathering native vegetation into piles. Composts cure in one to three 
months, depending on both ingredients and conditions. Decomposition can be 
speeded up by turning and adding substances high in N. Composts are frequently 
acidic and are sweetened with lime when they are piled. This also shortens 
curing time, since the desirable microbes prefer a neutral medium. 
13.4 Texture
Soil texture refers to density, particle size, and stickiness, all of which 
affect the soil's drainage and water-holding characteristics. The most important 
quality of the soil for marijuana is that it drains well - that is, water does 
not stand in pools after a rain, and the soil is not constantly wet. In a 
well-drained soil, the roots are in contact with air as well as water. 
Cannabis does best on medium-textured soils: soils that drain well, but can hold 
adequate water. Loams, silts, and sands usually drain well and are loose enough 
to permit good root development. Some clays and most mucks are too compact to 
permit the lateral roots to penetrate and grow. In addition, they often drain 
poorly, and when dry they may form hard crusts or clods, a condition marijuana 
cannot tolerate. 
Several simple tests will indicate the consistency and drainage qualities of 
your soil. Test when the soil is moist but not wet. First, dig a hole three feet 
deep to check the soil profile. In a typical non-desert soil, you will find a 
layer of decaying matter on the surface, which evolves into a layer of topsoil. 
Most of the nutrients available to the plant are found at this level or are 
leached down from it. The topsoil layer is usually the darkest. It may only be 
an inch thick or may extend several feet. When in good condition, the topsoil is 
filled with life. Healthy topsoil contains abundant worms, bugs, and other 
little animals, and is interlaced with roots. If you can easily penetrate the 
underlying topsoil with your hands, its texture is light enough for healthy root 
growth. 
The next layer, or subsoil, may be composed of a combination os sand, clay, and 
small rocks, or you may hit bedrock. Sandy, rocky, and loamy subsoils present no 
problems as long as the topsoil is at least six inches thick. Clay or bedrock 
often indicates drainage problems, especially if the spot has a high water table 
and stays wet. 
Next scrape up a handful of soil from each layer. Press each handful in your 
fist, release it, and poke the clump with a finger. If it breaks apart easily, 
it is sandy or loamy. Clods that stick together, dent, or feel sticky indicate 
clay or muck. 
To test for drainage, fill the hole with water. Wait half an hour to let the 
moisture penetrate the surrounding soil; then fill the hole with water again. If 
the water drains right through, you are working with sandy soil. If it doesn't 
drain completely within 24 hours, the soil has poor drainage. 
13.5 pH
The pH is a measure of how alkaline (bitter) or acid (sour) the soil is. The pH 
balance affects the solubility of nutrients, and helps the plant regulate 
metabolism and nutrient uptake. The scale for measuring pH runs from 0 to 14, 
with 7 assigned as neutral. A pH below 7 is acid; a pH above 7 is alkaline. 
Marijuana grows in soils with a pH range from 5 to 8.5, but it thrives in nearly 
neutral soils. Relative to other field crops, it has high lime requirements, 
similar to those for red or white clover or sunflower. But it does well in 
fields where plants with medium lime requirements, such as corn, wheat, and 
peanuts, are grown. 
The solubility of nutrients is affected by soil type as well as by the pH. In 
soils with a high content of organic matter, all nutrients are soluble between 
5.0 and 6.5. Phosphorous, manganese, and boron are less soluble at pH values 
above 6.5. Acid soils are usually found in the United States east of the 100th 
meridian and along parts of the West Coast, and a deep topsoil layer. Marijuana 
does best in acid soils when the pH is adjusted to a range of 6.3 to 7.0. 
{Figure 58. Map of pH for US.} 
Mineral soils in the dry western states may be slightly acid to highly alkaline. 
Most nutrients are very soluble in these soils, as long as the pH ranges from 
6.0 to 7.5. Some of these soils are too alkaline (over 8.5); so their pH must be 
adjusted to near neutral to ensure healthy growth. 
Adjusting the pH
First test the soil pH in the garden area. Previous gardeners may have adjusted 
native soils, or your yard soil may have been trucked in to cover poor native 
soils, so that the pH of your garden soil may be different from that of other 
soils in the area. Different soils vary in the amount of material needed to 
adjust the pH. Sandy soils do not require as much as loam, and loam requires 
less than clays, partly because of the chemistry, and partly because of the 
density and physical qualities of the soils' particles. 
Adjusting Acid Soils
Acidic soils are treated with limestone, which is expressed as an equivalent of 
calcium carbonate (CaCO3). Limestone is usually quarried and powdered, contains 
large amounts of trace elements, and comes in different chemical forms: ground 
limestone, quicklime, and hydrated lime (which is the fastest acting form). 
Dolomitic limestone is high in magnesium and is often used to adjust 
magnesium-deficient soils, such as those found in New England. Marl (ground 
seashells) is also mostly lime and is used to raise soil pH. Eggshells are 
another source of lime. They should be powdered as finely as possible, but even 
so, they take a long time to affect the soil. Wood ashes are alkaline and very 
soluble; so they have an almost immediate effect. 
Every commercial lime has a calcium carbonate equivalent or neutralising power 
which is listed on the package. To find out how much to use, divide the total 
amount of limestone required by the pH test (see Figure 59) by the calcium 
carbonate equivalent. For instance, a field requires fifty pounds of limestone, 
but the calcic limestone you are using has an equivalent of 1.78. Divide the 50 
by 1.78. The resulting figure, about 29 pounds, is the amount required. 
Commercial limes also list the grade or particle size of the powder. In order of 
fineness they are: superfine, pulverised, agricultural grade, and fine meal. The 
finer the grade, the faster the action. {Figure 59. Approximate amount of lime 
required to adjust pH of a 7" layer of different types of soil.} 
For best results, lime should be added at least four or five months before 
planting. In this way, the lime has a chance to react with the soil. But acid 
soils can be limed profitably and time before planting, or after, as long as the 
lime does not come into direct contact with the plants. Most growers add lime at 
the same time that they fertilise and turn the soil. That way, tilling and 
conditioning are handled in one operation. The lime should be worked into the 
soil to a depth of ten inches. Lime can also be added by spreading it before a 
rain. Make sure that the soil is moist enough to absorb the rain, so that the 
lime does not run off. Growers who have not adjusted the pH can dissolve lime in 
water before they irrigate. However, this is not advised if the water runs 
through a hose or pump, because mineral buildup may occur in the equipment. 
Adjusting Alkaline Soils
Most alkaline soils have a pH no higher than 7.5, which is within the range for 
optimum growth. Soils that are too alkaline can be adjusted by adding gypsum, 
which frees insoluble salts, and include iron, magnesium, and aluminium 
sulphate. Marijuana has a low tolerance for aluminium; so marijuana growers 
should use iron or magnesium sulphate in preference to aluminium sulphate. 
Sulphur and gypsum are worked into the soil in the same manner as lime. 

{Table 19.}
Some growers correct alkaline soils by adding an organic mulch or by working 
acidic material into the soil. Cottonseed meal, which is acidic and high in 
nitrogen, can also be used. As it breaks down, cottonseed meal neutralises the 
soil. Pine needles, citrus rinds, and coffee grounds are all very acidic, and 
can be used to correct alkaline conditions. The addition of soluble nitrogen 
fertilisers aids the breakdown of these low-nitrogen additives. (See Table 22 in 
the section on "Fertilisers" in this section.) 
Adjusting Alkali Soils
Alkali soils (pH usually above 8.5) are hardpacked and crusty, and sometimes 
have an accumulation of white powdery salts at the surface. They may not absorb 
water easily and can be extremely difficult to work. To prepare alkali soils 
with a permeable subsurface for cultivation, farmers leach them of their toxic 
accumulation of salts. The soils is thoroughly moistened so that it absorbs 
water. Then it is flooded so that the salts travel downward out of contact with 
the roots. Gypsum can be added to free some of the salts so that they leach out 
more easily. Gypsum can be added at the rate of 75 lbs per 100 sq.ft., or 18 
tons per acre. Leaching requires enormous quantities of water, an efficient 
irrigation system, and several months. 

{Plate 1.  Skylights are a good source of bright, unobstructed light.
Thai plant (closest) and Colombian plants reached over 14 feet in six months.

Plate 2.  Top: A hidden garden using fluorescent light, foil reflectors, and
bag containers.  Plants are ten weeks old.  Bottom: Simple to construct dome
greenhouse in southern California.  At two months, some of these plants are
six feet tall.

Plate 3.  Upper left: Stem of a female plant. Upper right: In full sunlight,
a pruned plant can grow incredibly dense. Bottom: A garden in the wilds of
Oregon mountains.

Plate 4.  Marijuana does well in most gardens. Top: Here a female plant is
in early bloom at five months. The main stem was clipped at three months
(Berkeley). Middle: Lower branches are spread out to catch the sun. Bottom:
A female bud about two weeks before harvest.  Leaves show some damage from
leafhoppers (insects shown).

Plate 5.  A giant sinsemilla cola grown from Mexican seed in northern
California.

Plate 6.  Top: Purple colours often appear late in life, when vigour is
waning. Lower left: Resin glands glistening on a purple, female flowering
shoot. Lower right: Yellow male flowers and purple leaves against a normal
green leaf.

Plate 7.  Top: Male flowers at different stages in development. A line of
resin glands can be seen on the anthers of the open flowers. Lower left:
Resin glands lining the pollen slit of an anther (x40). Middle right: Male
flowers in full bloom. The leaves are covered with fallen pollen. Lower
right: Gland heads may fall with the pollen grains. Mature grains are
spherical in field of focus (x40).

Plate 8.  Top: Resin glands on the lower (adaxial) surface of a small, fresh
leaf blade. Integrals are one millimetre (x16). Middle and lower left:
Stalked glands are concentrated along the veins of the lower leaf surface
(x40). Lower right (x100).

Plate 9.  Top: Upper (adaxial) fresh leaf surface. Left of picture, from
left to right: Sharp-pointed cystolith hair, stalked gland, and tiny bulbous
gland (x40). Lower left: Upper surface of a Thai leaf (x16). Lower right:
Upper surface of fresh homegrown Colombian leaf (x40).

Plate 10.  A young female flower (homegrown Colombian). Resin glands are not
yet fully developed (x16).

Plate 11.  Top left: A mature female flower from the same plant is in Plate
10. The flower bract is swollen from the ripe seed it contains. Notice the
well-developed resin glands (x25). Top right: A mixture of seeds from common
marijuana varieties shows comparative size. Bottom: The tip of a sinsemilla
flower at harvest. Notice cream-coloured stigmas to the left and the fresh,
clear resin glands (x40).

Plate 12.  Upper and lower left: An overly ripe sinsemilla flower bract.
Many gland heads are brown or missing (top, x16; bottom, x40). Upper and
lower right: Carefully handled Thai weed with intact glands. Notice the high
concentration of glands and very long stalks on this bract (top, x16; bottom,
 x40).

Plate 13.  Upper and lower left: A Colombian Gold. Gland contents are brown
and stalks have deteriorated on this bract (top, x16; bottom, x40). Top
right: Hawaiian; well-handled and showing little deterioration (bract x40).
Middle right: Gland heads easily detach from stalks when overripe (leaf vein
x40). Lower right: Stalked glands on both upper and lower leaf surfaces
beginning to brown (leaf margin x40).

Plate 14.  Top: Whitefly larvae and their honeydew excretions on the lower
surface of a leaf. Middle left: Leaf showing whitefly damage and a tiny
adult. Lower left: White speckles on leaves indicating mite damage. Lower
right: An overdose, or overuse of pesticide, can kill the plant.

Plate 15.  Upper left: Healthy green plant next to a N-deficient plant.
Middle left: Ultraviolet burn. Plant was moved outdoors without
conditioning. Lower left: "Bonsai" marijuana grown from a cutting. Upper
right: Mg-deficient plant has chlorotic leaves dying from their tips. Lower
right: Afghani variety, with characteristically wide leaf blades, show minor
symptoms of N deficiency (pale leaves and red petioles).

Plate 16.  Upper left: Male flowers lose some green and turn "blond" during
slow drying. Upper right: Cigar joints made with undried marijuana, which is
wrapped with lone blades of fan leaves before drying. Bottom: Sequence shows
change in colour in one day from sun curing.{Unfortunately, all the plates
are in black and white.}}
Another method of reclaiming alkali soils is by adding a thick mulch and letting 
it interact with the soil during the winter. The mulch should be about nine 
inches thick, or 130 lbs or more per 100 sq.ft. This thick layer neutralises the 
salts and also helps to retain moisture. 
Nutrients
Marijuana is a high-energy plant which grows quickly to its full potential in a 
fertile soil that is rich in available nutrients. Nutrients are found in the 
soil's parent materials: sand, clay, humus, minerals, rocks, and water. 
Nutrients dissolve in soil water (soil solution), which is then absorbed by the 
plant. In complex chemical processes, roots release ions in exchange for 
nutrients that are dissolved in the soil solution. 
The soil acts as a reservoir for the nutrients. Most of them are in 
non-exchangeable forms: that is, they do not dissolve, or dissolve only slightly 
in water. Only a small percentage of the total reserve is free at any time as 
the result of chemical processes or microbial action. Healthy soils maintain a 
balance between free and unavailable nutrients, so that the plants they support 
continually receive the right amounts of required nutrients. Alkali soils have 
large supplies of compounds which are extremely soluble. The solution is so 
concentrated that alkali soils are often toxic to plants. 
There are three primary nutrients, N (nitrogen), P (phosphorus), and K 
(potassium). These are the nutrients that gardeners are most likely to be 
concerned with and which most fertilisers supply. Soils are most likely to be 
deficient in one of these nutrients, especially N. 
In addition to the primary nutrients, soil supplies plants with three secondary 
nutrients, Ca (calcium), Mg (magnesium), and S (sulfur), and seven 
micronutrients: iron, boron, chlorine, manganese, copper, zinc, and molybdenum. 
Although deficiencies of all the secondary and micronutrients are reported from 
various parts of the United States, serious deficiencies do not occur often. 
((For a discussion of the symptoms of nutrient deficiencies is marijuana, see 
section 9.)) 
Marijuana absorbs nutrients primarily through a fine network of lateral roots 
which grow from the taproot. Lateral roots may spread over an area with a 
diameter of five feet, and may go as deep as the roots can penetrate. Plants in 
deep sandy soils or in soils that have porous mineral subsoils may grow roots as 
deep as even seven feet. Roots which can absorb nutrients from a larger area are 
more likely to fulfil the plants' needs than are shallow roots which result in 
shallow topsoil layers over compacted subsoils. When the roots have a large area 
from which to absorb nutrients, the soil does not need to be as fertile as when 
the roots are restricted to a small area by poor soil or by being grown in pots. 

You can get a good indication of soil fertility by observing the vegetation that 
the soil supports. If the vegetation is varied, has a lush look to it, is deep 
green, and looks vigorous, it is probably well-supplied with nutrients. If the 
plants look pale, yellowed, spindly, weak, or generally unhealthy, the soil is 
probably deficient in one or more nutrients. 
Testing
Agricultural colleges, County Extension Agents, and private companies perform 
soil analyses for a small fee from a sample you mail to them. The tests include 
nutrient, pH, and texture analyses, and are very accurate. There are also 
simple-to-use test kits available at nurseries and garden shops which give a 
fair indication of soil fertility and pH. Test results include a suggested 
fertiliser and lime program catered to the soil's individual requirements for 
the crop to be planted. Marijuana has nutrient requirements similar to those for 
corn, wheat, and sugarcane, and prefers just a little more lime (a more alkaline 
soil) than those crops; so soil can be fertilised as it would be for those 
crops. 
Soil tests are one indication of soil fertility. They test for available 
nutrients, but not for reserves that are held in the soil. Test results may also 
vary because of recent rainfall, changes of moisture content, and seasonal 
changes. Most soil tests do not measure the ability of the soil to make 
nutrients available. This is a very important factor when considering a 
fertiliser program and should not be overlooked. As an example, an uncultivated 
field showed only moderate amounts of N available, and indicated a need for N 
fertiliser. The vegetation - tall grass, weeds, and bush - had a healthy look 
and was dark green, and the lower leaves remained healthy. Obviously, the soil 
was able to supply an adequate amount of N to the plants, which withdrew it from 
the soil solution as it became available. The soil and plants had reached a 
balance, and the soil solution slowly became more dilute over the course of the 
season. 
To a great extent, the soil's ability to maintain a constant and adequate supply 
of nutrients depends on the soil's humus content. Humus can support dense 
populations of microorganisms. As part of their life processes, microorganisms 
decompose organic matter in the humus. Nutrients contained in the organic matter 
are released by microbes as simply inorganic molecules (e.g., NO3) which can 
dissolve in soil water. Generally, soils with a high humus content can keep 
plants supplied with more nutrients than soil tests indicate. 
The Primary Nutrients
If you look at any fertiliser package, you will note three numbers on the 
package. They stand for N-P-K, always in that order. Marijuana does best in a 
soil which supplies high amounts of N and medium amounts of P and K. 
Nitrogen
The availability of N is the factor most likely to limit the growth of 
marijuana. For fast healthy growth, marijuana requires a soil rich in available 
N. Nitrogen is constantly being replaced in the soil solution by microbial 
breakdown of organic matter. Some microorganisms can use N directly from the 
atmosphere. They release N as waste in the form NO3, which is the primary form 
in which plants absorb N. A small amount of N is also dissolved in falling 
rainwater. When the soil is moist, it loses N through leaching and to plants. In 
its available form (NO3, NO2, NH4), N is very soluble and may be carried away 
with runoff or may drain into the subsoil. 
Probably the most accurate method of measuring a soil's ability to produce N is 
by the percentage of organic matter in the soil (see Table 20). Organic matter 
releases N at a rate that is determined by the type of soil, the temperature, 
and the moisture. Generally, the more aerated and warmer the soil, the faster 
organic matter decomposes and releases N. Most professional testing services 
report the percentage of organic matter, and some sophisticated kits can also 
test for it. 
In its available state, N is tested in two compounds, ammonium (NH4) and nitrate 
(NO3). Test results are converted into PPM (parts per million) of N and then 
added to arrive at the total amount of N available in the soil. The formulas to 
convert nitrate and ammonium to N are (NO3) * 0.226 = N, (NH4) * 0.78 = N. Each 
PPM indicates 10.7 pounds of N per acre available in the top 7.87 inches. If the 
soil level is deeper, there is probably more N available. If it is shallower, 
less is available. But a test for available N gives only a fair approximation of 
the soil's ability to feed the plant. An individual test may be untypical 
because of recent leaching or depletion during the growing season. 
An intensively cultivated crop of hemp takes about 250 pounds of N per acre or 
six pounds per 1,000 square feet from the soil during the growing season. When 
the plants are spaced well apart, the crop does not require as much N. 
Fields which have more than 200 lbs of available N per acre (or 4.5 lbs per 
1,000 sq.ft.) at the start of the growing season require no additional 
fertilisation. Soils with less available N will probably yield a larger crop if 
they are given additional N. Actually, the amount of N that can profitably be 
used depends on the soil and its potential to produce N as well as on other 
factors: how fast N is lost, the soil depth, and moisture content. 
One way to calculate the amount of N to add to the soil is to build your soil to 
an "ideal" level. For example, an Iowa silt loam may test about 1.6 pounds of N 
per 1,000 sq.ft. and an organic content of 3 percent. Together, the available 
and potential N total about 3.2 lbs per 1,000 sq.ft. To increase the available N 
to 4.5 per 1,000 sp.ft., you would need to add 1.3 lbs of N. 
Phosphorus
P is an important nutrient which is used directly by the soil bacteria as well 
as by the plant, so that an increase in the amount of P in the soil often 
results in an increase of N. Because of P's low solubility, it is rarely leached 
from the soil. It is usually found in the greatest concentration in the soil's 
top layers, where it accumulates as a result of decomposition of organic matter. 

In slightly acid organic soil, up to one percent of the total P is available at 
any time. The total amounts of P in soils range from 1,000 to 10,000 lbs per 
acre. For example, a typical Kansas prairie soil has 3,000 lbs per acre. In 
soils with a lower pH, more of the P is tied up in insoluble compounds of iron 
or aluminium. In highly alkaline soils, the P forms insoluble compounds with 
calcium. 
Insoluble P reacts with the dilute acids that are released during decomposition 
of organic matter. These compounds are available to the plants. Both the 
chemical processes in which P is released and the organic processes of 
decomposition occur faster in warm soils. 
If P is available, young plants absorb it rapidly, and may take in 50 percent of 
their lifetime intake by the time they are only 25 percent of their adult size. 
Young plants grown outdoors in cold weather may grow slowly until the soil warms 
up and more P is available. Older plants grown out of season in cold weather 
sometimes exhibit purple leaves. This condition may result from a P deficiency, 
because of the unavailability of P at low temperatures. 
Most soil-test kits test available P, but the nutrient value of P is usually 
expressed as phosphoric acid (P2O5), which is converted using the formulas P * 
2.3 = (P2O5),(P2O5) divided by 2.3 = P. Any soil that has available P of 25 lbs 
per acre (0.58 lbs per 1,000 sq.ft.) or more is well-supplied with P. Stated in 
terms of phosphoric acid, this is 25 * 2.3 = 57.5 lbs per acre (1.33 lbs per 
1,000 sq.ft.). 
Most inexpensive soil kits test available P. Soil that test less than 1 PPM or 
10.7 lbs per acre (0.25 lbs per 1,000 sq.ft.) of available P should be tested to 
make sure there are adequate reserves, or can be fertilised to assure maximum 
yield. Soil-test kits give only a fair indication of the P available. A low 
reading may indicate the plants are absorbing P as fast as it breaks down from 
its unavailable form, especially during early growth! The main factors affecting 
the rate at which P becomes available are the total amount of reserve P in the 
soil and the pH. 
Most professional soil analyses include a report of reserve P. Generally soils 
with reserve P of 3,000 lbs per acre (70 lbs per 1,000 sq.ft.) do not need 
additional P. Intensively cultivated and cropped fields may have had their 
reserve supply depleted, and will lock up available P that is supplied as 
fertiliser until a balance is reached. 
Potassium
K is found in adequate quantities in most soils which have a pH within the range 
needed for growing marijuana. K is held in soils in three forms: unavailable, 
fixed, and readily available. Most K is held in the unavailable form as part of 
the minerals feldspar and mica. But a small percentage of the total K in any 
soil is held in fixed, slightly soluble forms. Some of these can be absorbed and 
used directly by the plant. The exchangeable K is equal to a fraction of the 
fixed K. Each soil maintains a balance or ratio of unavailable to fixed and to 
exchangeable forms. Organic soils have a higher percentage of K in the fixed or 
available form than mineral soils. As K is used by the plants, some of the 
unavailable K goes into the more available forms. Plants can use K in both the 
soluble and the fixed forms. 
Most clays and soils that are well-limed have adequate reserves of K. Acidic 
soils generally have low K reserves. Mucks, silts, and peats have low reserves 
of K, and have little capacity to hold it chemically when it is applied. Sands 
have K reserves, but little capacity to convert it to a fixed or available form. 
Most western soils have adequate reserves or K. The exchangeable K in soils 
becomes fixed if the soil dries out; so the available K of a recently dried soil 
is usually low. 
K is tested in its elementary state, but when described as a nutrient, it is 
given as potash (K2O). The formulas for converting are K * 1.2 + (K2O),(K2O) 
divided by 1.2 + K. Soils with 180 lbs or more of available potash per acre (4 
lbs per 1,000 sp.ft.) have an adequate supply. The total reserve K should test 
no lower than 900 lbs per acre (21 lbs per 1,000 sq. ft.). 
The Secondary Nutrients
Magnesium (Mg), calcium (Ca), and sulfur (S) are usually found in adequate 
quantities in soils suitable for growing marijuana. However, some New England 
soils do have Mg deficiencies. Soils which have a neutral or near-neutral pH 
almost always have adequate Ca and sulfur levels. 
Magnesium deficiencies are corrected by adding 50 to 100 lbs of Mg per acre 
(2.25 lbs per 1,000 sq.ft.). The most inexpensive way to add Mg is to use a 
dolomitic limestone for adjusting soil pH. Dolomitic limestone is about 12 
percent Mg (see Table 21); so 800 lbs of it are needed to supply 100 lbs of Mg. 
Dolomitic limestone releases Mg to the soil gradually. For faster action, epsom 
salts (magnesium sulfate, MgSO4) can be used. Five hundred lbs of epsom salts 
are required to supply soil with 100 lbs of Mg. Mg deficiencies can also be 
corrected by using foliar sprays. Dissolve one ounce of epsom salts in a gallon 
of water and spray all foliage. 

{Picture  The relationship between soil pH and relative plant nutrient
availability.  The wider the bar, the more the availability.  This chart is
for soil types recommended in this book..
	{Nitrogen - pH of 6.3 to 8
	 Phosphorus - 6.5 to 7.5
	 Potassium - 6.5 to 9
	 Sulfur - 6 to 9
	 Calcium - 6.7 to 8.5
	 Magnesium - 6.5 to 8.5
	 Iron - <4 to 6
	 Manganese - 4.7 to 6.5
	 Boron - 5 to 7 or 9
	 Copper and Zinc - 5 to 7
	 Molybdenum - 7}}
Micronutrients
Micronutrients are used by plants in minute quantities, and most soils contain 
enough of them to meet plant requirements. Home gardeners and guerilla farmers 
seldom encounter any micronutrient deficiencies. But heavily cropped lands 
sometimes develop a deficiency of one or more micronutrients because of crop 
depletion. Micronutrients are made available to the plants only if there is a 
delicate balance in the soil chemistry, and it is easy to create toxic 
conditions by adding them to soil when they are not needed. For that reason, 
soils should be treated with micronutrients only when symptoms occur or when the 
deficiency is known by analysis or past experience. Only small quantities of 
additives are required for treatment. Manures, composts, other organic 
fertilisers, lime, rock powders, and ash contain large quantities of trace 
elements. Active organic additives quickly release micronutrients in a form that 
is available to the plants. 
Boron
Boron deficiencies in marijuana occur in acid soils as a result of depletion by 
heaving cropping. The areas most affected by it are vegetable fields in the 
mid-Atlantic states, alfalfa and clover fields east of the Mississippi, and 
truck farms and orchards in the Northwest. Boron is found in phosphate 
fertilisers, gypsum, and lime, and is the main ingredient of boric acid and 
borax. When borax or boric acid are used, they are applied at the rate 10 to 20 
lbs per acre. They are used as a foliar spray at the rate of 1 ounce per gallon 
of water. 
Chlorine
Chlorine deficiency does not normally occur. Some chemical fertilisers contain 
chlorine, and toxic conditions occur infrequently. Toxic chlorine conditions are 
eliminated by leaching. 
Copper
Copper deficiencies occur infrequently in truck farms in Florida, California, 
and the Great Lakes region. Wood shavings and tobacco contain large amounts of 
copper. A foliar spray composed of 1 ounce each of calcium hydroxide and copper 
sulfate (a fungicide) per gallon of water is used by commercial vegetable 
growers. 
Iron
Iron deficiencies occur in orchards west of the Mississippi and in Florida, and 
in alkaline soils in which iron is largely insoluble. Lowering soil pH often 
solves the problem. Chelated iron, which is water-soluble, is available at most 
nurseries and quickly supplies iron even when pH is extreme. Humus and seaweed 
are excellent sources of iron. 
Manganese
Manganese deficiencies occur in the Atlantic states, the Great Lakes area, Utah, 
and Arizona. Manganese is found in manure, seaweed, and some forest leaf mould 
(especially hickory and white oak). Manganese deficiencies can be corrected by 
using a foliar spray of manganese sulfate at the rate of 0.5 to 1.0 oz. per gal. 
Soil is sometimes treated with manganese sulfate at the rate of 20 to 100 lbs 
per acre. In neutral or alkaline soils, most of the manganese sulfate becomes 
fixed and unavailable to the plants by the end of the growing season. 
Molybdenum
Molybdenum deficiencies occur primarily along the Atlantic and Gulf coasts and 
in the Great Lakes region. Plants need extremely small amounts of molybdenum, 
less than 1 PPM in leaf and stem tissue. Molybdenum deficiencies occur when the 
soil is too acidic. By raising the pH level, one can make molybdenum available. 
Zinc
Zinc deficiencies occur in soils throughout the U.S., primarily because of heavy 
cropping. It is most likely to occur in acid-leached sandy soils, and in neutral 
and alkaline soils where it is insoluble. In soils with high amounts of 
available P, zinc is also unavailable. Many deciduous tree leaves and twigs, 
composts, slag, and rock phosphate contain large amounts of zinc. Zinc sulfate 
is used as foliar spray at the rate of 3 oz. of zinc sulfate per gallon of 
water, or as a soil treatment at the rate of 100 lbs per acre. Some orchard 
growers drive galvanised nails into the trees to provide zinc. 
13.6 Fertilisers
Most soils can benefit from a realistic soil-conditioning program. Most organic 
programs build soil, and minimise leaching and runoff. Programs using chemical 
fertilisers emphasise immediate increase in yield and a minimum of labor. The 
approach that you use should be tailored to the soil's needs and to your 
situation and goals. For example, a home gardener interested in building soil 
quality can easily add manure or compost to his garden. But a guerilla farmer 
may use concentrated chemical fertilisers, which are easy to transport to a 
remote area. A farmer cannot use the labor-intensive techniques which a small 
planter might use as a hobby. Many gardeners use both organic and inorganic 
fertilisers. 
Organic Fertilisers
Organic fertilisers are usually less concentrated than chemical mixes. Their 
bulk consists of fibrous materials which condition the soil by aiding drainage 
and increasing the organic content and water-holding capacity. As they are 
decomposed by microbial action, the nutrients they contain are released in 
soluble form. Since this is a gradual process, there is little chance of 
creating toxic conditions. 
Manures and composts are basic, all-purpose conditioners. They contain adequate 
amounts of most of the nutrients that marijuana absorbs from the soil and can be 
used generously. Uncomposted manures are "active" and should be used only in the 
fall. Over the winter they compost in the ground. Composts and composted manures 
can be added in the spring. Table 22 lists some common organic fertilisers which 
are usually available. Some of them, such as bone meal and granite dust, break 
down slowly and are available only after a period of time. Others are low or 
lacking in one or more of the major nutrients. Organic fertilisers can be 
combined to provide a complete balance. 
Chemical Fertilisers
Most chemical fertilisers act quickly because all the nutrients are in soluble 
form. They are usually more concentrated than organic fertilisers, and can 
toxify the soil and kill the plants when they are overused. Fertilisers come in 
various concentrations and ratios of nutrients. All packaged fertilisers list 
the percentages of N-P-K (actually n-(P2O5)-(K2O)). Also listed is the potential 
acidity or alkalinity, that is, the number of pounds of lime or sulfur required 
to counteract pH changes caused by the fertilisers. Chemical fertilisers are 
often incompatible with each other; so home gardeners who use them should buy 
them pre-mixed or as a complete component fertiliser set. 
Solubility is a major problem with commercial fertilisers. In irrigated areas as 
well as areas with rainfall during the growing season, they are likely to be 
leached away; so they must often be applied several times during the growing 
season. A typical program might be to fertilise at planting and every six weeks 
thereafter until the beginning of flowering. When spreading fertilisers during 
the growing season, do not let them come into direct contact with the roots. An 
easy way to fertilise during the growing season is to make a small trough 
between rows with the corner of a hoe. Fertiliser is placed in the depression. 
Some new chemical formulas release nutrients during the length of the growing 
season, and therefore need only one application. 
Amounts to Use
The amounts of nutrient needed per acre and per 1,000 sq.ft. are shown in Table 
23. Soils rich in one nutrient may be average or deficient in another. To 
calculate the required amount of a specific fertiliser, divide the amount of 
nutrient required as listed in the chart by the percentage of nutrient in the 
fertiliser. For instance, to add 5 lbs of N to an area by using bloodmeal, 
divide 5.00 by 0.15. The total comes to a little more than 33 lbs. Dried cow 
manure contains about 1.5 percent N. About 333 pounds of it are needed to supply 
5 lbs of N. Urea, a chemical fertiliser, contains 46 percent N. Only 11 pounds 
are required to supply 5 lbs of N. 
Planning a Garden Fertiliser Program
Now let's plan some garden fertilisation programs, to help some cultivators in 
three areas which have different soils and climates: New England, Kansas, and 
Florida. We'll see how growers with different goals adjust their garden soil. 
New England
Most New England soils, and many soils in humid temperate areas, have a thick 
layer of humus which supplies N. New England soils also contain moderate amounts 
of P, but they are low in K. 
Our first gardener has a typical New England soil in his backyard. From tests 
and observation he thinks his soil contains moderate amounts of N and P, but is 
low in K. A test indicated a pH of 5.8. He plans to start preparing his 
ten-foot-square plot (100 sq.ft.) in the fall, before frost. By planting time, 
he expects his backyard garden to have a pH of 6.7 and a balanced, fertile soil. 

From Figure 59 he finds that the soil requires about 8.1 lbs of lime. He has 
decided to adjust the pH by using dolomitic limestone (with a calcium carbonate 
equivalent of 0.45) because farmers in the area sometimes complain of Mg 
deficiencies. Dividing 8.1 by 0.45, he finds that the soil requires 18 lbs of 
limestone. (Lime requirements divided by calcium carbonate equivalent equals the 
amount of limestone needed.) 
He guesstimates that the N content of his soil rates between fair and medium, 
and figures the soil can use almost 0.2 lbs of N. He has decided to spread fresh 
manure from a nearby stable mixed with lime. In the spring he will turn this 
into the soil; at the same time, he will add manure composted with hay and table 
scraps. The fresh horse manure contains about 0.44 percent N. To find out how 
much manure he needs, he divides 0.2 (the amount of N required) by 0.0044. The 
total comes to about 45.5 lbs. (Nutrient required divided by percentage in 
fertiliser equals amount of fertiliser needed.) The manure also contains 0.17 
percent phosphoric acid (P2O5) and 0.35 percent potash (K2O), referred to 
hereafter in this chapter as P and K, respectively. Multiplying 0.17 percent 
(0.0017) and 0.35 percent (0.0035) by 66 lbs, he finds that he has added 0.11 
lbs of P and 0.23 lbs of K. (Lbs of fertiliser times percentage of nutrient in 
fertiliser equals amount of nutrient in fertiliser.) 
  BOX F 
  Chemical fertilisers usually supply P in the form of superphosphate or triple 
  superphosphate. These chemicals are manufactured by mixing rock phosphate with 
  acids. Potassium is supplied by means or muriate of potassium (K and chlorine) 
  or sulfate or potash, which are mined in the Southwest and purified. All these 
  chemicals are soluble and are available to the plant. But a portion of them 
  gradually reacts with the soil and becomes fixed or unavailable. As this 
  portion becomes unavailable, it increases the total reserve in the soil, which 
  reaches a new balance of available to unavailable nutrients than before 
  fertilisation. 
  Bone meals and rock phosphate, the most commonly used organic sources of P, 
  and granite dust, a source of K, are not readily available, but increase the 
  total reserve of nutrients and gradually increase the total amount of 
  available nutrients. However, there is some time lag before these nutrients 
  are available to the plant. They are usually applied in large amounts, at 
  about three times the weight calculated for fertilisers of that concentration. 
  But one treatment lasts four years or more, because the fertilisers remain 
  fixed in the ground until they are used. {Table 24} 
From Table 23 he finds that the soil requires about five ounces of P. How many 
ounces of P is 0.11 lbs? He multiplies 0.11 by 16, the number of ounces in a 
pound, and finds that the total is about 1.75 ounces. The soil requires another 
3.25 ounces. Bone meal is about 20 percent P. To supply three ounces of P, about 
a pound of bone meal is required. But bone meal breaks down slowly, and is 
therefore applied at three times the rate used for other fertilisers; so our 
cultivator uses 3 lbs. 
Since the K content of this New England soil is poor, about 0.3 lbs of K is 
required. The manure has already supplied 0.2 lbs; so the soil requires another 
0.1 lb. Our cultivator decides to use wood ashes from his fireplace. Wood ashes 
are about 7.0 percent K. He divides 0.1 by 7 percent (0.07) and finds that the 
soil can use at least 1.4 lbs of ashes. He adds this in the spring just before 
planting, because the ashes are highly soluble. Over the winter, such highly 
soluble nutrients would leach away or become unavailable. 
Our grower knows that some of the N in the fresh manure that was added in the 
fall will leach away during the winter. But the manure compost that he adds in 
the spring will more than make up for any losses. 
A New England farmer not for from the cultivator has been rotating his field 
from corn and marijuana to alfalfa and pasture for the past ten years. Each fall 
he adds 7 tons of manure per acre. Except for occasional additions of lime, no 
other fertilisation is necessary. 
A rural New England grower has decided to plant in a remote mixed-forest area. 
The first 10 inches of soil is a rich compost of humus. It is full of life: 
insects, worms, and other creatures. The grower has decided to increase the 
fertility of the soil by using chemical mixes and dolomitic lime. He is 
cultivating in three clearings with a total area of about 1,000 sq.ft. He 
guesstimates that the soil is medium in N and P, but poor in K. It is also acid. 
He applied enough lime to correct the soil's natural acidity and the pH of the 
fertiliser. 
Using Table 23, he decides that he should purchase a mix with a ratio of 50 
parts of N, 10 parts of P (reading from the medium line), and 120 parts of K 
(from the poor line), that is, a ratio of 5-1-12. A local nursery sells 
commercial fertiliser with nutrient percentages of 10-5-25, close enough to the 
desired ratio. By taking the total amount of N required for a medium soil as 
listed in Table 23 (19 ounces), and dividing it by the N in the fertiliser (10 
percent or 0.10), the rural grower finds the total amount of fertiliser required 
(190 ounces, or a little less than 12 lbs). The other nutrients are 
automatically added in the same ratio. 
Kansas: A cultivator in Kansas decides to plant along a hidden stream bank. The 
banks are covered with lush vegetation as a result of runoff that contains 
soluble fertilisers used on nearby farms. The cultivator feels that additional 
fertilisers are not necessary, since the vegetation is so lush. 
Another grower in Kansas found that her soil was very low in N and P, but high 
in K, typical of dry midwestern and western soils that support scrub vegetation. 
It had a nearly ideal pH. She started to prepare her 200 sq.ft. garden in the 
spring after the rain season ended. Using Table 23, she found that it required 
3.5 lbs of N, 6 ounces of P, and no K. Activated sludge (5-3-0) was available at 
the local garden centre. To find out how much sludge her garden required, divide 
3.5 by 5 percent (or 0.05). The total comes to 70 lbs. 
Florida: A grower planting 500 sq.ft. on a deserted ranch in central Florida 
started with a very sandy soil whose pH was 4.9 because of sulphurous water in 
the ground. From Figure 59, she found that the soil required about 35 lbs of 
lime. To adjust the pH, she used 14.0 lbs of a limestone with a calcium 
carbonate equivalent of 2.5. 
The soil had virtually no organic matter, and she was not sure she could use the 
same location next year; so she decided to apply soluble mixes throughout the 
growing season. From Table 23, she found that "poor" required 28 ounces of N, 4 
ounces of P, and 24 ounces of K. A chemical fertiliser with nutrient percentages 
of 15-5-10 was on sale at a local discount store. To find out how much 
fertiliser is needed to supply 28 ounces of N, divide 28 by 15 percent (or 
0.15); the result is about 186 ounces of N, or about 11.5 pounds. Since the 
other nutrients are supplied at the same proportions or at higher proportions 
than are required, no supplements are needed at planting time. But additional 
feedings will be required periodically during the growing season. 
13.7 Techniques for Preparing Soils
Each garden situation is unique, and many factors help determine which garden 
techniques you should use. These include the soil's condition, the size and 
location of the garden, commitment, and personal preferences. Each technique 
affects the microecology in its own way. Home gardeners may use techniques that 
are impractical for a farmer or guerilla planter. But all growers have the same 
goal when they prepare soil for planting: to create a soil environment conducive 
to growing a healthy, vigorous plant. 
  BOX G Fertilising Cannabis Depends on the Crop
  Historically, Cannabis is known to require high fertility. In a fertile soil, 
  Cannabis can outgrow practically any annual plant. Cannabis also is a known 
  depleter of soils. This is true particularly with marijuana, since seeds, 
  flowers, and leaves comprise the harvest. Hence it's necessary to fertilise 
  the plants each year. Hemp, on the other hand, comes from the Cannabis stem, 
  and the fibre consists primarily of cellulose (C6H10O5)n. When hemp is grown, 
  all plant parts except the fibre are returned to the soil; so the nutrients 
  are also returned. Moderate fertilisation, if any, is all that's required for 
  hemp farmers. 
If you are already growing a vegetable garden, the chances are that your soil is 
in pretty good shape for growing marijuana. However, vegetable gardens may be a 
little acidic, particularly east of the 100th meridian. The soil should be 
prepared in much the same way that it is prepared for corn cultivation, with the 
addition of lime to raise the pH to near neutral. 
Tilling
Gardens which may not have been planted recently (in the last three or four 
years) require more work. It is best to begin preparing the soil in the fall, 
before the first frost. This can be done using a spade or shovel. The ground is 
lifted from a depth os six or eight inches and turned over so that the top 
level, with its grass and weeds, becomes the bottom layer. Large clumps are 
broken up with a blade or hoe. Larger areas can be turned with a power hoer or 
rototiller. Conditioners, such as fresh leaves, composts, mulching materials, pH 
adjusters, and slow-release fertilisers are added and worked into the soil, so 
that they begin to decompose during the winter. It is especially important to 
add these materials if the soil is packed, mucky, or clay-like. Soluble 
fertilisers should not be added in the fall, since they leach to the subsoil 
with heavy rains. 
In the spring, as soon as the ground is workable, turn it once again. If the 
soil still feels packed, add more conditioners. If you are using manure or other 
organic materials, make sure that they are well decomposed and small clean and 
earthy. Fresh materials tie up the N in the soil while they cure, making this 
nutrient unavailable to the plants. Commercial fertilisers and readily soluble 
organics, such as blood meal and wood ash, are added at this time. 
The ground can also be seeded with clover or other legumes. Legumes (alfalfa, 
clover, vetch, etc.) are plants which form little nodules along their roots. The 
nodules contain bacteria which live in a symbiotic relationship with the plant. 
As part of their life processes, these bacteria absorb gaseous nitrogen from the 
air and convert it into a chemical form the plant can use. During its life 
cycle, clover uses up most of the N, although some leaks into the surrounding 
soil. But when the plant, or any of its leaves, die, the contents become part of 
the soil. The process of growing a cover crop and turning it into the soil is 
sometimes called green manuring. 
After the last threat of frost, at about the same time that corn is planted, the 
soil should be worked into rows or mounds, or be hoed. At this time, the seeds 
should be planted. If any concentrated fertiliser is added to the soil, it 
should be worked into the soil and should not come into direct contact with the 
seeds. 
The actual amount of tilling that a given soil requires depends on soil 
condition. Sandy soils and light loams may need no turning, since they are 
already loose enough to permit the roots to penetrate. Turning may break up the 
soil structure, damaging its ecology. These soils are easily fertilised, by 
using soluble mixes or by the layering technique described below. Soils which 
are moderately sandy can be adjusted by "breaking" and levered or pushed, but 
the soil is not raised. This is done about every six inches, and can be 
accomplished quickly. Farmers can loosen sandy soil by disking at five or six 
inches. 
Some gardeners mulch the soil with a layer of leaves or other materials to 
protect it from winter winds and weather. This helps keep the soil warm so that 
it can be worked earlier in the spring. In states that border west of the 100th 
meridian, this helps prevent soil loss due to erosion from dry winds. Soil often 
drains well in these areas, and the ecology of the soil is better served when it 
is left unturned. At season's end, marijuana's stem base and root system are 
left in the ground to help hold topsoil. The next year's crop is planted a cover 
crop, such as clover, or alfalfa, which holds the soil and also enriches the 
nitrogen supply. 
Layering
Layering is another method of cultivation. The theory behind this program is 
that in nature the soil is rarely turned, but builds up, as layer after layer of 
compostable material falls to the ground. This material, which contains many 
nutrients, gradually breaks down, creating a rich humus layer over a period of 
years. 
The layering method speeds up the natural process. Since gardens are more 
intensely cultivated than wild fields, new material is required to replenish the 
soil nutrients. Gardeners like Ruth Stout "sheet compost," that is, they lay 
down layers of uncomposted material and let it decompose at the same time that 
it serves as a mulch. But most gardeners prefer to use material which is already 
composted. The compost shrinks and builds the topsoil layer about an inch for 
every six inches of compost. After several years, the soil level will be raised 
considerably, and the top layers will be an extremely rich, porous medium which 
never needs turning. In order to prevent a spillover of the soil, gardeners 
usually construct simple beds (using boards) to contain the garden areas. 
Layering is most successfully used on porous soils, especially sands, which 
contain little organic matter. It can also be used with clay soils. However, 
experienced growers say that clays should be turned several times before the 
technique is used, or the first couple of harvests will be small. 
Planting a cover crop such as clover will give the soil structure. As more 
compost is added, the clover is covered and the new seed planted. The clover, 
with its N-fixing properties, remains a permanent cover crop. When marijuana 
seeds are to be planted, a planting row is easily tilled with a hoe. The clover 
protects the soil from sun-baking and its resulting water loss, and makes it 
harder for weed seeds to get started. 
Tilling and layering are basic methods which are used with many variations. In 
some ways, there almost seem to be as many gardening techniques as there are 
gardeners. For instance, one gardener bought three cubic yards of topsoil and a 
cubic yard of composted steer manure. He mixed the material and filled raised 
beds with it to a depth of 18 inches, and had an instant high-power garden. 
Another grower made compost piles in his raised troughs during the winter. By 
planting time, the compost was complete and filled with earthworms. The beds 
became warmer earlier, and he could plant sooner. 
A midwestern gardener used marijuana as a companion crop in much the same way 
Indians used corn. In between the marijuana, she planted beans and squash. She 
didn't get many stringbeans and only a few squash. But she believes that the 
beans gave the plants extra N, especially during the first six weeks, and the 
broad squash leaves protected the soil from the hot August sun. 
A gardener in Georgia had such a sticky clay soil that a shovel once got stuck 
in it. He dug holes two feet deep and two feet wide with a power auger and 
filled them with a fertile mix of two parts sand, one part clay, three parts 
topsoil, and one part chicken manure. He claimed that his plants grew six feet 
in 10 weeks. Filling holes with a rich soil mixture is popular with guerilla 
farmers, who often must plant in poor native soils. 
Mulching
Mulching is a labor-saving technique that many gardeners and farmers use for a 
multitude of reasons. A mulch placed on the ground before fall frosts helps the 
soil retain heat and protects it from winds and freezing temperatures. In the 
spring the mulched soil becomes warmer earlier in the season, and can be planted 
several weeks sooner than usual. A mulch cover keeps the seedlings' roots warm 
and eliminates a lot of weeding, since most weed seedlings cannot pierce the 
cover. 
During the summer, mulches keep the ground cooler and more moist by absorbing 
and reflecting light and reducing surface evaporation. These are important 
points for farmers in dry areas. The water savings can be 50 percent or more. 
Any plant or animal material will do for mulch. Gardeners use hay or straw, 
leaves, composts, manures, sawdust, bark, or plant clippings in two- to six-inch 
layers. A barber in Palo Alto uses hair. Baled hay is inexpensive and easy to 
use as a mulch. Round hay bales unroll in a long sheet that is easy to spread 
over the ground, and square bales can be pulled apart into tile-like squares. 
Mulches create an ideal environment for earthworms and microorganisms which 
condition and enrich the soil. These organisms require a relatively cool, moist, 
dark environment. The mulch develops a dry outer crust which reflects light, 
keeping the underlayers cool and moist. Materials such as leaves, bark, and 
sawdust decay slowly because they do not contain enough nitrogen to maintain 
dense populations of decomposing microorganisms. Manures and composts contain 
more nitrogen and decay more quickly. 
With few exceptions, mulches can be applied practically any time of the year, 
but the best time is probably in the fall, after the crop is harvested and 
before the ground has frozen. Leaves, plant clippings, and straw are applied in 
a thick layer from six to ten inches deep. Hay is layered two to six inches 
deep. Denser substances, such as manures and composts, should be mixed with 
straw and leaves to aid decomposition. This mixture is spread in an even layer, 
about two to four inches deep, over the entire surface of the garden. If winds 
pose a problem by blowing the mulch away, you can cover it with newspapers or 
sheets of plastic held down with rocks. If your area is dry, give the mulch a 
good soaking once before frosts. 
By the spring, much of the material will seem to have disappeared. But 
underneath the top layer, you will find a soft-textured, earthy-smelling humus, 
teeming with worms, insects and other small animals. This is a sign of a healthy 
ecosystem and a fertile soil. 
Some people apply mulch in the spring, placing it between rows as they sow the 
seeds. The mulch keeps weeds from competing with the seedlings, absorbs the 
sun's warmth, and releases nutrients to the soil. 
In cold areas, such as Montana, New England, and Alaska, growers place black 
plastic sheets over the soil. These absorb the sun's heat, allowing the soil to 
be planted sooner. The seedlings develop quickly in the warmer soil. The plastic 
is removed once the seedlings are well-established. 
Newspapers and white plastic can be used to decrease water loss during the 
summer. They also reflect light back to the plants. 
One innovative grower from western Colorado placed a sheet of white plastic over 
her garden and cut out holes wherever she plant the seeds. Though it is quite 
dry where she lives, she didn't need to water the plants until late July. And 
she had no problems with any weeds. 
Containers
Containers are another option open to grower. Plants can be grown full-size in 
containers which are at least five gallons (larger would be better). Fill them 
with high-grade topsoil, or a plating mixture as described in section 6. 
Planters are a convenient compromise where the soil is particularly poor or for 
the home gardener who does not wish to get into large-scale gardening. But 
remember, eight good-sized plants can yield over four pounds of grass. 
Plants in pots need to be watered frequently, but require much less total water 
than a garden. The gardener can also move the plants. Some gardeners use this 
technique to maximise the amount of sun the plants get during the day, or as the 
sun's position changes with the season. And growers can easily induce early 
flowering by moving the plants to a darkened area. {Figure 61. Containers are 
convenient for outdoor gardens.} 
Almost any large container that can withstand the weight of moist soil and which 
has holes for drainage is suitable. Containers which held toxic chemicals, 
herbicides, insecticides, or other possibly harmful substances should be 
avoided. 
We have seen all kinds of ingeniously made containers. Some growers use old 
bathtubs, and others use wooden packing crates or bushel baskets. A simple wood 
container 18 inches wide, eight feet long, and 18 inches deep was made by a New 
Jersey grower, who grew six plants in it. Trash cans, plastic containers, 
barrels, and even rubber tyres have been used. One grower grew plants in 
one-cubic-foot bags of soil by cutting a five-inch-diameter hole in the top and 
poling holes for drainage. To assure drainage, growers sometimes fill the bottom 
of each container with a six-inch layer of stones or gravel; is you are planning 
to move such container, lightweight perlite would be more suitable. 
13.8 Guerilla Farming
Guerilla growers often use the same techniques as home gardeners. But the soil 
that they start with is sometimes marginal, and the gardens are in remote, 
hard-to-get-to areas; so they modify the techniques to fit their needs. When it 
is impractical to carry bulky organic fertilisers to the growing site, guerilla 
farmers use highly concentrated commercial mixes. Compost and soil adjusters are 
gathered from the surrounding area, and the simplest, most light-weight tools 
are used. Some growers use horses or mules to carry equipment and material, and 
then use the animal to plough. The animals are quiet and, naturally, require no 
external power source. Experienced growers say that the animals can work as fast 
as or faster than a rototiller. 
It is hard to generalise about details of guerilla farming, since much depends 
on the specific circumstances, which can vary greatly. For instance, a grower 
who plants along the fertile bank of a midwestern stream may not need to do more 
than pull out weeds and till the actual planting area. But a grower planting on 
a mountain slope may have to "build a soil," since soil and nutrients are washed 
from the slopes and down to the valleys by rainfall. For this reason, we will 
cover several situations separately: forest; washed-out steep areas; swamps and 
marshes; stream banks; grasslands and fields; and arid soils. 
Forest Clearings
Clearings in forests have always been popular places to plant because they offer 
security from detection. They vary greatly in drainage qualities, fertility, and 
pH. The drainage qualities of forest soils depend on the depth of the humus 
layer and the structure of the underlying subsoil. But most of the forest 
remaining in the U.S. is sloped, and water that is not absorbed by the soil runs 
off. 
Soils are created in forests from the leaves, branches, animal droppings, etc., 
which accumulate on the forest floor. The first trees to grow are long-leaf 
pines, such as jack pines, which can grow in relatively infertile soils. Their 
roots penetrate deep into the subsoil to obtain some nutrients. Short-leaf 
pines, conifers, and firs appear as the humus accumulates, since they require a 
more fertile soil than long-leaf pines. Pine-forest soils vary in fertility from 
poor to fair, and are usually quite acidic. In the Northeast their pH may be as 
low as 3.5, but generally the pH ranges from 5.0 to 6.0. In order to support a 
high-energy, lime loving crop like marijuana, they require fertilisation and 
liming. Long-leaf pines sometimes grow in compacted clay soils, which also 
requires tilling. 
As the soil evolves, deciduous trees (tree that drop their leaves each winter), 
such as oak and maple, may begin to grow. Deciduous forests, sometimes called 
broad-leaf or hardwood forests, have the best soils. These forest floors are 
covered with bushes, grasses, mosses, and other small plants. They have an 
adequate rainfall and a humus-rich soil, which is porous, holds water well, and 
can support a healthy marijuana crop, although additions of nitrogen fertilisers 
would probably spur growth. Hardwood forest soils have a pH range from 6.0 to 
7.5. The soil in timbered forest land has a much smaller humus content, 
especially if it has been clearcut. 
Mountain Soils and Washed-Out Steep Areas
Mountain slops characteristically have little soil matter; their surface is 
composed largely of rocks, gravel, and sand. For longterm use they could be 
terraced so the newly formed soil in not washed away, but most growers are 
interested in more immediate results. These "soils" do not provide much of an 
anchor for marijuana's taproot and do not permit a network of lateral roots to 
form. Many of these soils also suffer from a low water table, since they drain 
rapidly. But there may be some sand and a bit of organic matter built up along 
gullies or in depressions or other natural traps. Such soil has usually had most 
of its nutrients leached out, but may contain some phosphates and potassium and 
considerable amounts of trace elements. The easiest way to adjust these soils is 
to use a well-balanced, slow-release, concentrated fertiliser. Bloodmeal, with 
its high N, works well with these soils. 
One grower in the badlands of North Dakota used a timed-release 32-9-26 
fertiliser in his "rock garden." He spread it just below the surface at the 
beginning of the growing season. Every time that it rained, his plants received 
nutrient-rich water. Toward the middle of the season, he noticed the lower 
leaves begin to pale, so he fertilised them periodically with urea. Heavy rains 
leach soluble fertilisers away, and in rainy areas they need to be applied three 
to four times during growth. 
Containers can also be used in this environment. Growers use plastic bags or 
folded milk cartons instead of backpacking with a column of containers. When 
they get to the site, they fill the bags with a mixture of sand, as much as they 
can find, and gravel. The greater the ratio of sand to gravel, the longer the 
container will hold water. 
One grower doublelayers heavy-duty polyethylene bags, and lines them with 
heavy-duty paper cement sacks or burlap bags. He fills the bag with gravel, then 
pours in sand and shakes it. He says that the mix is just about right when it 
looks like a can filled with gravel with sand in the spaces. He carries on a 
watering and feeding program much as he would for any hydroponic system. 
Swamps, Marshes, or Bogs
These soils are very high in fibrous organic material, but are low in calcium 
and in available N, P, K, and Mg, which are leached from the soil or are 
insoluble because of the low soil pH. Since these soils are constantly wet, 
Cannabis roots cannot come in contact with air; as a result, the plant's growth 
is stunted, and the lower stem becomes susceptible to stem rot. These soils need 
to be adjusted to support a healthy crop of marijuana; they must be drained, 
fertilised, and limed. On a small scale, the easiest way to modify them is by 
constructing raised mounds, hills, or rows, at least one foot wide at the top 
and two feet high. The raised areas drain well, leaving relatively dry soil. 
Wood chips, chopped brush, sawdust, or perlite may be added to keep the mound 
light and the soil loose and aerated. 
Wet soils are usually highly acid and should be limed. Once the lime interacts 
with the soil, nutrients which were locked up become available to the plants. 
Since these soils are rich in organic matter and have a high rate of microbial 
action after they are loosened and limes, they may need little fertilisation. 
Grasslands and Fields
These soils are usually fairly fertile and can support a worthwhile crop with 
little effort. They are usually well-drained, although they may be a little too 
dry or too wet. (If they have unusually large numbers of earthworms, they are 
probably a little too wet.) Their pH is usually between 5.5 and 6.5, although it 
may range up to 7.0. These soils are usually loams, which need only tilling in a 
two-foot radius, three or four inches deep, around each plant. All weeds and 
grass should be pulled from the area. Some growers mulch the cultivated area 
with newspapers, leaves, or dead grass. A grower in the Midwest adds crushed 
eggshells and a commercial timed-release fertiliser when he plants. He feels 
that this "extra boost" makes the difference between an adequate crop and a 
bountiful crop. Other growers periodically fertilise with soluble mixes. Some of 
these soils have to be irrigates during the long summer droughts. If they 
aren't, the plants won't die, but they will not grow to full size.
Stream Banks and Canal Ditches
These are some of the most convenient areas for growers to plant, since they 
provide an ample supply of water, which may contain fertiliser runoff. Stream 
banks are an area that marijuana naturally colonises, and the planter usually 
needs only to cultivate the area to be sown, and cut surrounding bush so that 
the young plants can compete with established plants. It the surrounding 
vegetation looks pale and stunted rather than lush green and vigorous, the soil 
should be fertilised. These soils are sometimes low in calcium, which dissolves 
readily in water. Lime should be added to correct for acidity. 
Sometimes the ground is a little too wet early in the growing season, although 
it dries out later on. Planting on hills or mounds is often used to solve this 
problem. 
Arid Areas
Soils which have a low water table and dry out by June or July need to be 
irrigated to grow marijuana successfully. When irrigation is not feasible, 
growers plant along drainage ditches, streams, and canals, or look for green 
spots which indicate springs or underground reservoirs. Other growers use 
containers to minimise water loss. One grower in Arizona dug holes two feet wide 
and three feet deep, and lined the sides with thin polyethylene. He said that 
when he watered during the summer drought, he did not lose much water to the 
surrounding soil. 
Arid soils usually have little organic matter, and drain quickly with extensive 
runoff. Some of them have a subsurface layer of clay, and therefore hold water 
on the surface until it evaporates. In any case their texture can be improved 
greatly by working in organic matter. The soil should be loosened at least two 
feet down. This loosening allows the taproot to develop deeply so that it can 
reach underground water during the drought. 
Arid soils more often drain well, are alkaline, and contain P, K, and trace 
elements, but are low in N. Fish meal, cottonseed meal, blood meal, or manure 
may be the only additive the soil needs. 



Chapter 14
PLANTING AND TRANSPLANTING
After the soil is adjusted, you are ready to prepare it for planting the seed. 
Sowing is an important process, since the post-germination or seedling stage is 
the most critical for Cannabis. You can increase the seedlings' chance of 
survival by sowing the seeds properly. 
14.2 When to Plant
Most hemp-growing manuals advise that the seeds should be planted about two 
weeks after the last threat of frost, which is the same time that corn is 
planted. As a rule of thumb, you need not plant until this time in areas that 
have a growing season of five months or more. These areas include most of the 
United States, except for Zone One (see Figure 62) and mountainous areas of the 
country. 
Growers in northern areas report that plant have survived light evening frosts 
with little or no damage. We think of marijuana as a tropical plant, 
experiencing no chills in its native climes. But the mountainous areas of 
marijuana cultivation in Mexico and Colombia often have frosts during the 
growing season. One grower, describing spring (April) conditions in Nebraska, 
reported "plants (from tropical seed) three and four inches tall were covered 
with snow in the evening. By midafternoon all the snow had melted, and those 
little sprouts were healthy as could be." 
Early-season sprouts do face more risks than later-germinating plants do. A 
lingering freeze or chill can weaken or kill them. Sometimes seeds or seedlings 
get washed away be heavy rains or flooding, or become infected from wet soil. 
They are also prey to hungry herbivores, who savour the tender young shoots, 
especially in the early spring, before the native plants have sprouted. These 
predators include rabbits, groundhogs, rats, mice, and possibly squirrels and 
cats, as well as large animals, such as deer, cattle, and sheep. Birds 
frequently eat the seeds and young shoots, especially if the ground looks 
planted. Snails and insects, such as cutworms and leafhoppers, also eat 
seedlings. Don't let this impressive list of dangers dim your enthusiasm. 
Although these problems do occur, they can be controlled or prevented with a 
little but of planning (see section 16). {Figure 62. Average date of last 
expected spring frost for US.} 
As you can see in the Spring Thaw map (Figure 62), the last date of expected 
frost varies from early February in parts of Florida, Louisiana, Texas, 
California, and Nevada to mid-June in the coldest regions of New England and the 
Midwest. Planting time varies locally, as well as regionally. Fields which 
receive direct sun warm faster than partially shaded ones. Fields covered with a 
layer of compost or fresh manure, or with black plastic sheets, retain more heat 
and are ready to plant sooner than other fields. Mountainous areas often vary 
considerably in planting time. Higher ground usually stays cold longer than 
low-lying areas. Since soil is dark, it heats quickly when exposed to sunlight. 
Soil is usually warmer in the late afternoon. 
The time that the soil warms also depends on the weather. During severe winters, 
a deeper layer of soil becomes frozen than during mild winters; so it will take 
longer to thaw. Soil below this layer is insulated by the ice and remains 
unfrozen. Spring weather, rainfall, flooding, and cloud cover also affect the 
soil's temperature. 
Actually, the only way to know whether or not a field is ready to plant is to 
feel it and look at it. Examine the soil in early morning. It should be easy to 
work, rather than hardened from ice. There should be no large frozen clods of 
soil or other organic matter. There should also be no fine crystalline ice 
particles which glimmer in sunlight. 
For fall harvest, sow outdoors after March 21, the first day of spring and the 
turn of the Equinox, when there are equal lengths of sun-up and sun-down. There 
are an additional 20 to 30 minutes of light before dawn and after sunset, for a 
total of 13 hours of daylight. When plants are started earlier, they may flower 
prematurely because of the short days. The plants may also be subject to sex 
reversal, and more males may develop. 
There is little advantage to starting Cannabis before April. Each plant has a 
certain genetically defined potential for growth and size. As long as the plants 
have enough time to grow and develop, usually five or six months, this potential 
is realised (some Colombian and Asian varieties may need longer to develop). 
Plants started before spring grow no larger in size than plants started during 
April. The younger plants are virtually indistinguishable from the older ones by 
harvest, and plants which are started earlier face more risks of detection and 
destruction. {Figure 63. Average date of earliest expected fall frosts for the 
US. Information about Australia can be found in an Atlas.} 
However, if you are faced with a short growing season, you can get a head start 
by germinating the seeds a week to six weeks before the local planting time, and 
transplanting the seedlings outdoors at about the same time seeds would be 
planted in your area. You can also hasten planting time by covering the area to 
be sown or planted with a clear (or black) plastic sheet, which will warm the 
ground by the greenhouse effect. 
14.3 Preparing to Sow
Growers sue three basic techniques to sow marijuana: rows, hills, and broadcast. 
Each method is suitable within a certain range of conditions and has its own 
advantages and disadvantages. 
Rows
Rows are convenient to use, especially for large areas. They are constructed 
easily using a how, plough, or tiller. 
Rows facilitate the care of gardens and fields by setting up an organised space 
in which the plants and surrounding area can be reached easily by the gardener. 
Weeding, watering, thinning, pruning, and harvesting can be accomplished very 
quickly. Larger fields are planted in roes to accommodate ploughs, planters, and 
cultivators. They are essential when fields are flood-irrigated. Furthermore, 
they provide a way to use space in the most efficient possible manner. But rows 
make detection easier, since they have an orderliness that plants do not exhibit 
in nature. 
On sloping and hilly ground rows are a major factor in soil conservation: such 
soil is easily carried away in windstorms and in the runoff after rain. For this 
reason, rows on hilly and sloping ground are contoured: curved to run 
perpendicular to the slope. 
Space rows two to six feet apart; plant seeds every four to eight inches ((In 
any description of planting which we give, we refer to 100 percent viable seeds. 
In this case, for example, if seeds are tested (see section 3) and have a 
viability of 50 percent, sow the seeds two to four inches apart. If they have a 
viability of 33 percent, sow them one to two inches apart.)) (See Box H.) 
To construct a row, break up any large clods on the surface of the soil. In a 
garden-size area this is easily done by striking them with the tongs of a rake. 
In larger areas a tiller or externally powered cultivator can be used. Then 
level the soil. 
If you need to irrigate or have problems with excessive moisture, use a hoe to 
raise the soil in alternate rows of hills and trenches. Pat the crests of the 
hills with the hoe or a shovel so that they are an inch or wider at the top, and 
four to eight inches high than the trenches. 
BOX H Plant Size and Spacing 
Plants vary tremendously in size and branching habits because of many factors, 
including variety, soil fertility, length of growing season, amount of light 
received by the plant, water, spacing, and pruning. As a result, one can have no 
firm rule about how far apart plants should be spaced. 
An individual full-grown plant may have a diameter at its base as wide as ten 
feet or as small as 18 inches. Most conical-shaped varieties (Colombian and 
Jamaican) grow between seven and 12 feet tall, and have a width between four and 
six feet. Mexican plants are somewhat taller and thinner, with a base diameter 
of three to five feet. Some exotic Indian, Central Asian, and Central African 
plants may have a diameter only one or two feet across. The descriptions are 
generalisations; there are many varieties within each country, and much 
variation within each variety. 
Pruned plants have a much wider base than unpruned ones. Plants pruned at the 
fourth internode and again a month later sometimes grow twice as wide as an 
unpruned plant. 
In order to catch as much sun as possible, rows should be orientated along a 
north-south axis, perpendicular to the course of the sun. The advantage of lush 
rows is more pronounced in southern than northern latitudes, but the 
solar-energy differential in north-south versus east-west rows is significant at 
all latitudes in the United States, and becomes more important on steep slops. 
Another factor is the orientation of the garden as a whole. Plants sown in a 
square plot whose sides point northeast and southeast get about 10 percent more 
light than ones in a plot whose sides point due north and due east. 
Hills
Hills and mounds are especially convenient for small plots. Low hills are often 
camouflaged to look like natural or wild stands, and are very useful in areas in 
which the land is too wet in the spring, because the hills drain above the 
ground level. They are easily adapted to meet unusual requirements. For example, 
a grower in New Mexico planted a doughnut-shaped hill eight feet in diameter and 
two feet thick, leaving a centre hole four feet in diameter. He placed a 
portable plastic tub in the hole after punching pinholes around the edges. To 
water he just filled the tub. In the swampy Everglades, two industrious farmers 
constructed a giant hill-row three feet thick and three feet high. The hill had 
such a good drainage that it kept the plant roots well-drained even during the 
rainy season. 
Hills are usually constructed between two and five feet in diameter. Small hills 
are usually planted with 15 to 20 seeds, and large ones may be sown with as many 
as a hundred. The hills are spaced three to 10 feet apart, so that each groups 
of plants gets a maximum amount of light. Hills can grow more than you would at 
first suspect. For instance, if you were to grow a hill three by three feet, you 
could harvest six to nine large plants. Their foliage would extend two and a 
half feet beyond the hill, for a total of about thirty square feet of foliage 
space. 
Broadcast Seeding
Broadcast seeding is the fastest and easiest way to sow, but is not an efficient 
way to use seed. Seeds are simply tossed or shaken onto the prepared ground, at 
the rate of about forty per square foot, and are then usually pressed into the 
soil with a light roller or by foot. This method is most effective in moist 
soils. Many of the seeds never germinate or die immediately after germination. 
The faster growing ones naturally stunt the others by shading them. This method 
is often used by guerilla farmers who want the stands to look natural and who 
wish to plant large areas quickly. An experienced grower can sow several acres a 
day by hand using this method. 
Seed Count
There are approximately 2,300 medium-sized seeds in an ounce, or about 85 per 
gram. An acre is about 43,000 sq. ft., or a square 208 feet on side. To plant an 
acre in rows two feet apart with a seed every four inches requires about 90,000 
seeds or 39 ounces (1,100 grams, or two pounds, seven ounces). At this rate, a 
ten-by-ten plot requires about 2.5 grams of seed. 
A typical hill field has four-foot-wide hills spaced about seven feet apart. A 
typical hill and surrounding area accounts for approximately 100 square feet. 
There are approximately 430 hills in an acre. If each of these is planted with 
100 seeds, the field requires about 43,000 seeds, which weigh about 18 ounces. 
Broadcasting requires a lot more seed. At the rate of 40 seeds per square foot, 
a grower uses about 2.3 ounces in a ten-by-ten plot. An acre requires about 47 
pounds, or 21 kilograms of seed. 
How to Plant
Finally, after the soil is adjusted, and the rows or hills are built, it is time 
to actually plant the seeds and watch your garden begin to grow. If you are 
growing with clover as a cover or companion plant, dig it up to a depth of four 
inches and chop up the soil. Water the soil to the point that it feels almost 
wet. Drill a hole with a seed drill, stick, or pencil, then drop one seed into 
the hole, cover it gently, and pat the soil down again. Marijuana seeds are 
large enough to handle individually; so each one can be planted separately. 
How deep one digs the holes depends on the kind of soil in which one is 
planting. Light woodsy or organic soils are planted 1/2 to 3/4 inch deep, so 
that the stem is held firmly in an upright position. Sands and light loams are 
planted 1/2 inch deep. Heavy loams and clay are planted 1/4 to 1/2 inch deep, so 
that the sprout's energy is not expended before it breaks through the soil. 
If you are broadcast seeding, you can increase the germination rate tremendously 
by screening a layer of soil over the seeds to help keep them moist. Seeds that 
dry out weaken or die. 
In a garden that has been mulched, lift away the mulch cover at each place you 
plant, and sow the seed in the underlying soil. 
In soft-textured soils, instead of digging or poking holes, press each seed to 
the desired depth, and cover or pat the soil smooth. 
14.4 Germination
The seeds need constant moisture in order to germinate. Therefore, the ground 
should be well-watered. Keep the soil moist by watering it with a light spray 
whenever it begin to feel dry. This may mean watering the immediate area once a 
day. You can keep the soil moist and hasten germination by covering the planted 
area with transparent glass or plastic. Most of the seeds should sprout in a 
period ranging from three days to two weeks. This variation depends on variety, 
age and condition of seed, and soil temperature; the warmer the soil, the faster 
the rate of germination. 
Once they have germinated, the seedlings should be kept moist until the roots 
grow deep enough to absorb an adequate supply of water from the subsoil. If the 
ground is still moist from spring rains, as it is in many of the eastern 
regions, you may not have to water at all. On the other hand, there are sections 
of the West which are completely dependent on irrigation. 
When the seedlings are only an inch or two tall, you can protect them from heavy 
rains or frosts by using drinking glasses, jars, or paper or plastic cups. You 
can protect larger plants with containers from which the bottoms have been 
removed. Transparent containers warm the soil by the greenhouse effect, 
capturing light and turning it into heat. In warm weather, use white or 
translucent containers, which prevent burn by reflecting some light and 
diffusing the rest. Containers also keep the soil moist, serve as plant markers, 
and protect the plants from some enemies. A grower in Berkeley, California, used 
cracked fish tanks to protect plants in the early spring. A guerilla farmer in 
the Poconos puts up four posts, one at each end of a row. She uses them as a 
frame for clear polyethylene covering, creating a small greenhouse. 
Growers in Zone Five sometimes harvest a spring crop by transplanting 
indoor-grown, two-month-old plants outdoors right after the last frost date. The 
naturally short days and long nights trigger the plants into flowering. (See 
Transplanting below, and the discussion of the photoperiod in section 3.) 
If started after May 15, marijuana may not have time to reach its full size or 
flower. This problem mainly affects growers in Zone One and in mountainous 
areas. But even if the plants do not grow to full size or flower, you can still 
harvest a potent crop of preflowering tops, which may be almost as potent as 
ripe buds. The harvest is not as large as a crop of buds, but it is more than 
worth the effort. 
14.5 Transplanting
Seedlings and young plants are transplanted after the last threat of frost. If 
the growing season in your area is less than five months, you may want to start 
the plants indoors, or in cold frames, transplanting when the weather permits. A 
10-by-four foot cold frame can easily hold 60 two-month-old plants. The cold 
frame can be constructed with two-by-two's or branches gathered at the site. 
Cover the frame with a double layer of six- or eight-mil polyethylene plastic or 
similar material. Attach the plastic to the frame with tacks or staple-gun 
tacks. If the area is unprotected from the elements, slant the roof so that rain 
will run off. If the area is windy, place rocks or branches along the frame to 
add weight. Orient the cold frame to face the south. 
In areas with a growing season of six months or more, plants will not 
necessarily get larger if they are started earlier than normal. Plants started 
at normal planting time catch up to the older plants by season's end. It serves 
no purpose to start plants before about March 21, the spring equinox. 
Where there is no threat of frost (in Hawaii, southern Florida, and parts of 
Texas, Louisiana, and California), growers can raise a winter crop. Grow the 
plants for two or three months under artificial light. Plant get off to a faster 
start under artificial lights than natural light during the winter months. Move 
or transplant them before the beginning of March. Most strains will flower 
because of the short days (less than 12 hours of light) and fill out to well 
formed plants by the end of May when they are ripe. 
For the normal summer crop, seedlings should be transplanted after the last 
threat of frost. The best time to transplant is on a rainy or cloudy day, which 
allows the plants to adjust to the new environment without the strain of intense 
sunlight. Plants grown in a cold frame or sunny window adjust more easily than 
plants grown under fluorescent lights. Plants grown under artificial light 
usually show evidence of shock when they are moved to sunlight. Near sea level 
they may lose some of their green colour and appear pale or yellowed. At high 
altitudes, such as mile-high Denver, the leaves may actually burn, turn brown, 
and fall. Healthy plants usually recover quickly by adjusting the new growth to 
the changed conditions. However, plant can be conditioned to the new environment 
by being placed in a partially sunny area, preferably where they are shaded 
during the middle of the day and receive either morning or late-afternoon 
sunlight. The plants need about a week to adjust. 
Seedlings grown in planting pellets for up to 10 days after germination can be 
placed directly in the soil. Peat pots should be scored with a knife so that the 
lateral roots can penetrate the pot more easily. Seedlings started in milk 
cartons or flower pots should be removed from the container so that the roots 
are disturbed as little as possible. Plan on using a pot size which is 
root-bound by the time that you transplant. (For the relationship between pot 
size and number of weeks, see Table 17.) To transplant, water the area to be 
transplanted and the plant. Then dig a hole a bit larger than the pot and loosen 
the surrounding and underlying soil. Place the plant in the hole, and pack the 
soil so that the stem base is at the same depth that it was growing at before. 
Firm the soil and water the area. 
In areas where ripoffs are expected, such as parts of Hawaii and California, 
some guerilla farmers transplant individual plants (one to each site) to sites 
which are widely spaced over the countryside. In this way they may lose some, 
but at least not all, of their plants to ripoffs. 
Each plant (one to three months old) is transplanted to a cone-shaped hole, two 
to three feet deep by two feet across the top. This strategy is well-suited to 
areas with poor soil. Since much of the hole is taken up by rootbound soil, it 
is easy to gather enough topsoil and sand to fill the hole. The gathered soil 
should also be mixed with organic or slow-release fertilisers which provide 
ample N and P. 



Chapter 15
CARING FOR THE GROWING PLANTS

15.2 Weeding
Marijuana is a fast-growing annual whose survival depends on its ability to 
compete with other fast-growing weeds. At the end of each season, plants growing 
in a wild stand may cover the ground with thousands of seeds per square foot. 
Many of these are relocated by wind, runoff, and birds, and some are destroyed 
or die. Other never receive the conditions they need to germinate; and of those 
that do germinate, many die as seedling. The remaining plants compete with each 
other and with other weeds for the available light, nutrients, and water. Even 
so, wild stands may be as dense as forty plants per square foot. In order to 
survive the competition, Cannabis expends a great deal of its energy during the 
first two month growing a main shoot which is taller than the surrounding 
vegetation. Then it develops lateral branches which shades the shorter plants. 
With their source of energy - light - cut off, the shaded plants stop growing 
and often die. 
When you cultivate - that is, eliminate weeds - the rate of germination and 
survival of your plants is increased enormously. Growers using clover, sheet 
composting, or mulch as ground cover can expect very little interference from 
weeds during seedling development. But plots of fertile, aerated, and cleared 
soil are open to colonisation by a wide range of plants; so you may have to weed 
several times before the marijuana's dominance is assured. 
When you weed, make sure not to pull out any weed seedlings which may have roots 
in the same area as the Cannabis roots. Instead, cut the weeds slightly below 
the surface with a cliperr, scissors, or your fingernails. Weeds more than six 
inches away can be safely pulled. Leave them to dry right on the soil. As they 
dry and decay, they return the soil's nutrient to it. 
Growers plagued with weeds can cover the soil with mulch, paper, or polyethylene 
sheets. One grower found that two computer sheets fit exactly between the rows. 
Another used torn drapes as a temporary ground cover. 
Once Cannabis has established dominance over an area, the other weeds are not 
able to interfere with its growth. But if there is wide spacing between the 
plants, the weeds may have open space and start to grow rapidly. Keep these 
weeds clipped short if water or nutrients are scarce. 
15.3 Watering
Marijuana requires an ample supply of water to live and grow. The actual 
quantities that it needs depend on the plant's size, the gardening techniques, 
type of soil, temperature, wind, humidity, and intensity of light. A vigorous 
plant may transpire several gallons of water a day during the hot summer months. 
If it receives less water then it need, it stops growing, wilts, and then dries 
out. {Figure 66 Areas with less than 30 inches of rain usually require some 
irrigation.} 
Seedlings
Marijuana germinates best in a moist soil. Within a week, it grows a taproot 
three or four inches long. By the end of the first month, the root system may 
stretch over an area a foot and a half in diameter and go more than one foot 
down. Until then, the soil should not be allowed to dry out. Plants which have 
germinated during warm, sunny weather may need to be watered until the roots 
have grown deep enough to reach sub-soil moisture. When the soil three inches 
below the surface feels dry, seedlings should be watered, preferably by using a 
watering can or the spray setting on a hose. Gently water the soil, making sure 
not to disturb the seedlings or the soil surrounding. The soil should be 
thoroughly saturated so the moisture percolates down, encouraging the roots to 
grow deep. If the surface is only lightly watered, the roots may grow near the 
surface, leading to water problems as the soil gets drier during the summer. 
After the first month, Cannabis does best when the soil goes through alternating 
moist and dry periods. This alternation allows the lateral roots to come into 
contact with air. By the end of the growing season, the root system may 
penetrate the soil to a depth of six feet or more. As long as they are not 
blocked by solid rock or dense clay, the roots grow by following a trail of 
moisture. If the trail leads deep, the roots follow. The deeper layers of soil 
are less likely to dry out during hot, dry weather. 
Older Plants
As a rule of thumb, Cannabis over a month old should be watered when the soil 
about six inches deep feels dry. But this rule provides only a rough indication 
that the plants need water, because there may be deeper sources of water that 
are not apparent. The most obvious indication of a problem is wilting. A more 
subtle one is slow growth during the (ordinarily fast-growing) vegetative stage. 

Since you want to wet the lower layers, you should thoroughly saturate the soil. 
If the soil is completely saturated, it should hold water for a minimum of a 
week. Usually only two or three waterings a month are required by a garden that 
is completely dependent on irrigation. 
The most efficient way to water is to let the water slowly seep into the soil, 
so that all the organic particles which hold the water are saturated. If the 
soil is very dry, and the water beads or runs off and is not absorbed, add 
household laundry detergent at the rate of one or two grams per gallon of water. 
It acts as a wetting agent, which breaks the surface tension. Once the soil is 
treated with a wetting agent, it usually absorbs water throughout the growing 
season. 
In drier areas where corn. cotton, and other deep-rooted crops are irrigated, 
marijuana also requires an additional source of water. But in areas where there 
are patches of wild hemp or where deep-rooted crops grow by using available 
ground water, marijuana does not need to be watered, although additional water 
may increase its growth. 
Box I
Water in General
Deep soil layers retain water much longer than the top layers. To encourage the 
development of a deep root system, saturate the ground when you water. The roots 
follow the moisture trail. 
Water conditions also vary from field to field. For instance, many mid-western 
farmers plant along the banks of meandering streams. Even in dry areas, these 
plants have a natural source of water. Mountainous areas are usually 
well-drained and dry out before valleys do. Low-lying fields remain moist later, 
and are saturated by runoff from higher ground. In browned areas, farmers look 
for green spots which indicate underground streams, springs or runoff. Planters 
look for deserted wells or active watermains with leaks. Fields high in organic 
matter retain moisture longer than other fields, and mulching may cut water 
evaporation by 50 percent. 
Watering Techniques
Gardeners may supply water by using a bucket, can, or water-hose. But growers 
with larger plots often rely on waterpumps to deliver river, lake, or well water 
to their gardens. Irrigation canals, drainage pipes and ditches, and water mains 
are sometimes convenient sources of water. The two most efficient methods of 
watering are the drip hose, which seeps water around the plant, and hand 
watering into an enclosed area around the plant's stem. 
There are several kinds of drip hoses. Some have perforations every three to six 
inches along their length. These are useful when marijuana is planted in rows or 
large hills. Another kind is actually a kit, consisting of a main feeder hose 
and several side hoses two to four feet long. Each side hose has a metal bulb at 
the end which can be adjusted to regulate water flow. The bulb lies near the 
plant stem. A drip bottle was invented by a grower in the dry area of Nebraska 
who was only growing a few plants. He punched pinholes in the bottom of several 
one-gallon milk jugs and placed a jug near each plant. The jugs slowly watered 
the garden. Every few days, he refilled the jugs from a nearby irrigation ditch. 
As the plants grew larger, he placed more jugs around them. The drip method 
moistens the soil slowly, but does not flood it; so the soil and its nutrients 
are not washed away. Since this method allows you to decide exactly where the 
water goes you need not waste any on non-productive land. 
Growers sometimes use elaborate setups, such as battery-electric, hand- or 
foot-powered, ram- or windmill-driven pumps. Foot-powered pumps are probably the 
most convenient for small plots. They are extremely lightweight (just a little 
heavier than a bicycle), inexpensive, easy to construct and disassemble, and 
virtually silent. Since you have much more power in your legs than in your arms, 
foot-powered pumps con do more work, and do it faster, than hand-powered pumps. 
Electric pumps are relatively quiet and pump and enormous amount for their small 
size. But they require a source of electricity. They cannot be used unless there 
is a power line available, although there are car alternators available which 
produce 110-volt current. 
Gasoline pumps and electric generators are heavy and noisy. Even with a muffler, 
they can be heard for miles in some country areas. They require a source of 
fuel, and often an elaborate setup, including rigid feed tubing, fuel tank, and 
platform. But once they are in place, the can deliver a tremendous amount of 
water. They are usually used by farmers growing large plots. Sometimes growers 
dig a hole in which they store and run the equipment. This setup helps muffle 
the sound and keeps the machinery in good working order. 
Ram- and windmill-powered pumps use running-water and wind energy, respectively. 
They come in many sizes and are often used to fill water tanks for later use. 
They can also be used to generate electricity to run electric pumps. They 
require no fuel, are usually silent, and can be constructed inexpensively. 
But some farmers have devised other methods for getting water to their plants. 
A farmer growing near Tucson, Arizona, trucks water to her plants twice a week 
using a pickup truck and four 55-gallon barrels. She attaches a garden hose to 
her tanks, and siphons the water to her garden, 200 feet downhill. 
Two foresighted farmers in Texas carried twenty 30-gallon plastic trash cans and 
lids to their garden. During the spring rains, they filled the containers from 
nearby gullies. By the end of the rainy season, the had collected enough water 
to carry them through the summer drought. 
A homesteader in Oregon's dry eastern section dammed a gully by using and earth 
stabiliser, plastic, wood and cement, and pipe. During the winter his private 
reservoir filled. 
Farmers near Atlanta tapped into a city water main. The pressure from the water 
main allowed them to pipe water uphill. 
15.4 Thinning
If the soil is kept moist during germination, most of the viable seeds that you 
planted will germinate and the seedlings will soon start to crowd each other. 
This happens frequently when the plants grow on their own. Then they grow into a 
dense hedge-like mass dominated by a few plant. The dominant plants typically 
have long internodes and a long sturdy stem with little branching. The shorter, 
bushier plants are shaded by the taller ones and become stunted from the lack of 
light. By thinning, you give the plants that are left enough room to grow to 
their full potential, and you choose the ones that you think will grow to be the 
best for smoking. Leave the plants that have dense foliage, are branching, and, 
later in the season, the ones that are the most potent. 
Thin the plants as soon as they begin to touch or crowd each other. This should 
be repeated as often as necessary. Seeds sown six inches apart in rows two feet 
wide require thinning several times during the season. But guerilla farmers 
sometimes let the plants compete so that the garden looks more like a wild 
stand. 
There are two methods used to thin: cutting the stem at the base so that the 
entire plant is destroyed, and cutting just the tops so that the plant's growth 
is thwarted, and the uncut plants shade it. The cut plants remain relatively 
inactive, and do not use much water or nutrients, but they do shade the ground 
and use otherwise wasted space. 
15.5 Staking
Outdoor-grown plants rarely need staking. When the stem bends from the wind or 
rain, tiny tears in the structure develop. These are quickly mended by the 
plant: it grows new cells which increase the girth of the stem and make it 
stronger. But plants which are suffering from nutrient deficiencies or are 
top-heavy because of competition may need to be staked. Heavy rain sometimes 
cause the plants to fall over, especially if they have shallow root systems 
which cannot hold the added weight. 
To stake, drive a sturdy rod six inches from the stem and deep enough into the 
ground to be able to give the plant support. Then tie the stem to the stake with 
wirer twists or string. 
If the stem or the branch is cracked, pinched, or bent at the base, its position 
should be corrected and held firmly with a splint. The splint can be held with 
masking tape. In a few days the plant grows tissue to support the damaged area. 
15.6 Pruning
Growers prune (clip or top) their plants to increase productivity, prevent 
detection, or to harvest early smoke. In the near future, new laws will 
decriminalise or legalise marijuana cultivation. These laws will probably limit 
legal cultivation either by the total gardening area or by the number of plants 
an individual or group may cultivate. Gardeners limited by space will maximise 
yield by cultivating a dense stand of tall, unclipped marijuana. Growers 
permitted to grow only a few plants will grow the largest, most productive 
plants possible. This is done by giving the plants the best possible growing 
conditions and a lot of space between plants to maximise light and minimise 
competition for water and nutrients. 
Unpruned marijuana develops in one of three classic shapes, depending on 
variety. Many Mexican and Thai varieties develop into a tall, narrow bush no 
wider then three feet and shaped like a poplar tree. Colombian, Cambodian, 
Indian, and some south Mexican and Vietnamese varieties are Christmas-tree 
shaped. Some Moroccan and Afghani varieties have complex branching and naturally 
grow into small, dense bushes, about five feet tall. Marijuana usually grows to 
its full height by early September. Most of the marijuana plants you are likely 
to cultivate will grow to between eight and fifteen feet tall. Some Hawaiian and 
Thai varieties average between twelve and twenty feet tall. 
Increasing Yield
When marijuana is clipped to increase the number of growing shoots, the total 
yield at season's end may not be increased. Provided that soil and water are not 
limiting to growth, each plant can reach a maximum size when given enough room. 
The more surface are the plant presents to light, the closer it will get to its 
maximum potential. Where the plants are grown with much space between them, 
clipped plants can yield more than unclipped plants, especially if the branches 
are spread out to maximise the light on the plant. When the plants are grown 
close together, the taller a plant is, the more sunlight it will receive, and 
hence the larger the possible yield. 
Some growers prefer to harvest a top stem that is thick with buds (colas). The 
largest colas form on the main growing shoot of unclipped plants. When the 
growing shoot is clipped from a plant, the new shoots and leaves grow slower and 
smaller than the main shoot of an unpruned plant because the capacity for growth 
is spread out over several shoots. When a plant is clipped early in the season, 
most of the difference in lead and bud size is made up by harvest time. 
Marijuana can be pruned at any time during the seedling or vegetative growth 
stage, but you should prune plants when they are young if you plan on harvesting 
growing shoots during the season. A seedling clipped anywhere from the fourth to 
sixth node will usually form at least six strong growing shoots that can be 
harvested during the third or fourth month. If these shoots are cut again while 
the plant is still young, marijuana often develops into a small, very compact, 
hedge-like bush. 
Yield can be increased by spreading the plant's branches so that more light 
reaches the inner growth. Cannabis stems are bent most easily when they are 
still green and fleshy, nearer to the new growth, but the whole plant can be 
bent to form a gentle arch with the top of the main stem in a horizontal 
position. Within a few days the side branches along the top will begin to grow 
vertically, competing with the main stem. They will soon develop their own 
horizontal side branches. To bend a plant, tie the main stem loosely with a 
cloth or heavy string. Tie the other end of string to a heavy weight or anchor 
on the ground. Don't put too much pressure on the stem as this tears some of the 
roots and weakens the plant. You can bend the plant a little each day until the 
plant is in the desired position. 
You may also increase yield by bending only the growing tip. This encourage the 
side branches to develop sooner than they naturally would. Only the flexible 
part (about the last foot) is bent. To bend the top, use stiff wire or wire 
twists used for plastic bags and wrapping vegetables. Fasten the other end of 
the wire lower in the stem to hold the tip in position. {(See Figure 49.)} 
A common mistake that cultivators make is pulling off the large leaves on the 
main stem (sun or fan leaves), when the plants are young. These leaves are 
removed by cultivators who believe that their removal will cause the undeveloped 
side shoots to grow. But fan leaves are net producers of sugar and energy, which 
are used by the side soots to begin growth. Rather than encouraging new growth, 
the removal of fan leaves slows growth. The plant will also be more susceptible 
to attacks from pests and predators. 
When the plant is several weeks old and growing well, the difference between 
plants with their leaves removed and those left intact may not be large. The 
biggest difference can be seen when leaves are removed from branches just prior 
to, or during, flowering. The buds that form from leaf axils with leaves removed 
are noticeably smaller than those where the leaves have been left on the branch. 

Detection
Cannabis can be detected from both the ground and the air. From the ground, 
marijuana is revealed by its familiar shape, unmistakable leaves, and odour. 
Tall plants are usually more conspicuous than shorter ones. From the air, stands 
may have a different colour than the surrounding vegetation, especially where 
natural vegetation is not as lush as marijuana. Individual plants usually have a 
circular profile when viewed from above; this can be altered by bending or 
pruning the plant. Varieties which are naturally tall-growing may need to be cut 
several times during the season to keep them hidden. 
Plants are sometimes cut back severely, to much as half their height when they 
get too tall, but this may damage the plant. A less drastic topping technique is 
to remove the opt foot of growth. Whenever new shoots get too tall they are 
clipped. But the plants should not be severely pruned late in the season when 
the growth rate has slowed (preflowering), because there will be fewer branches 
left on which buds can develop. 
If you are trying to conceal plants behind a fence or wall, start bending or 
pruning the plants early, at about one month of age. By starting early and 
continuing to prune during the vegetative growth stage, you will train the plant 
to branch and fill up the area. If you wait until the plants are already tall, 
you may have to cut the plants back severely or clip shoots continuously. 
15.7 Gardening Tips
Transplant Older Plants
A friend of ours was warned that his garden had been spotted by local 
authorities. Rather than cut down his four-month-old plants, he decided to 
transplant them. He dug the plants out, leaving a ball of soil about two feet 
square around the roots of each one. He wrapped each soil ball tightly in a 
plastic bag to transport it, and placed the plants in newly dug holes in a 
different spot. He kept the plants well-watered. After a few days, they 
recovered from transplant shock and started to grow once again. Transplanting 
large plants is not easy to do, but it could save a crop. The marijuana root 
system is not very extensive when the plants are in fertile soil with plenty of 
water; the tap root may only be six inches long on a ten-foot plant. 
Wind Protection
Hemp Cannabis planted closely together has been used by farmers to form a 
windbreak to protect other crops. If you are growing in an especially windy area 
such as the Midwest, you may wish to plant a perimeter if tightly spaced 
Cannabis to protect your garden. Construct a rope and stick fence against the 
windbreak to hold the plants upright and prevent them from falling into the 
central garden. Simply keeping the plants clipped short is a simpler approach. 
Inducing Flowering
Growers may wish to induce their plants to flower early, especially in the 
North, where the growing season is short. Plants in containers can be moved to a 
dark area for 12 hours of darkness or more per day. Black sheets of polyethylene 
film, dark plastic bags, and large appliance cartons can be used to provide 
periods of uninterrupted darkness. Use the dark treatment nightly until the 
plants are flowering (usually after one to two weeks of long-night treatments). 
Winter and Spring Crops
In southern parts of the U.S., Hawaii and parts of California, you can grow more 
than one crop in a season. Greenhouses that stay above freezing can also be used 
for year-round growing. Plants started during the winter or early spring get 
naturally long nights and flower early, when they are relatively small, usually 
no more than four feet tall. Flowering can be postponed by breaking the long 
nights with short periods of light. This extends the vegetative growth period, 
yielding older, larger plants at flowering. Start breaking the night period with 
artificial light when the plant is about a month old. Continue the treatment 
until you want the plants to flowers. (See the discussion of photoperiod in 
section 3.) 
Spring crops can be trimmed of buds when mature. The plant is left in the 
ground, and as the daylength increases, the plant will renew vegetative growth 
and flower once more in the fall. Plants can also be started in November or 
December indoors under lights and planted outdoors in February for harvest in 
April or May. The plants will grow faster under lights than they would outdoors 
under the weak winter sun. When they are placed outdoors, the long nights will 
induce flowering. By April the sunlight gets much stronger, perfect for flower 
development. Plants placed outdoors in February adjust easily to sunlight. Even 
so, they should be conditioned so that they do not suffer severe burn, as 
described in the Transplanting section in section 14. 
Rejuvenation
Plants grown in areas where the weather is mild can survive winter when there 
are no heavy freezes. During the winter the plants will grow very slowly, but as 
soon as the weather warms, and the light gets more intense, the plants respond. 
This technique can also be used to obtain a second growth crop during Indian 
summers. The second growth is not as vigorous as the original, but is does 
increase the total harvest. 
To prepare plants for rejuvenation, leave three or four pairs of lowers branches 
with leaves on the plant when you harvest. The leaves need not be large, but 
they must be green. Water and fertilise the plants. Within a few days the plants 
will show new growth. 
The authors observed an outdoor container composed entirely of plants which 
survived a mild San Francisco Bay Area winter. These developed healthy second 
growth the following summer and flowered again in the fall. Some growers in 
Hawaii claim that their plants are three years old and that the plants have 
yielded as many as six crops of buds. Perennial marijuana plants also grow in 
Jamaica and Thailand. 
Water Deprivation
Many cultivators begin to limit the amount of water their plants receive as soon 
as the flowers start to appear. Other growers give their plants as little water 
as possible after the middle of the plant's life. The plants are given small 
amounts of water only when they begin to wilt. (See section 9 on the reasons for 
stressing the plants.) 
Under water stress many of the leaves may die and fall from the plant. Sometimes 
the plants appear "burned," and turn brown or gold. At harvest, water-stressed 
plants may only have buds left on them and these may have the colour, resin, and 
harshness typical of Colombian grass. These plants yield less grass at season's 
end. Not only are they smaller overall, but many of the leaves will have fallen 
away. 
Water stress can be difficult to control in areas with heavy summer rain. 
Water-stressed plants often make up for their smaller size by a raped burst of 
growth after a heavy rain. One method of control is to cover the ground with 
plastic sheets when it rains so that most of the water runs off. 
Tacks and Nails
Some growers hammer nails or tacks into the stems of plants several weeks before 
harvest. Many growers use long thick nails; others prefer to use several 
half-inch-long tacks. The nails are usually placed at the base of the stem. This 
is supposed to "increase potency." {Figure 72. Wilted plant. Unless watered it 
will die.} 
Stem Splitting
This is a popular way to stress used by cultivators in the United States. The 
stem is split (not cut) at the base to from a space through the stem. Growers 
place a rock, small piece of wood, an old Cannabis stem, or piece of opium (in 
Africa) in the split. Sometimes the wound is bound with cloth or plastic. We 
don't recommend this procedure, and advise you to be careful not to kill the 
plants and ruin the harvest. 
Varieties
Outdoor growers are well-advised to plant several varieties of marijuana, 
because some varieties adapt to their new environment better than others. Also, 
each variety (and to small extent, each plant) has its own bouquet. By planting 
several varieties, cultivators assure themselves a varied selection of smoking 
material. 
In areas with short growing seasons, many tropical varieties do not have a 
chance to flower. But immature material from these varieties may be more potent 
than mature flowers of a plant grown from seed of lower-quality grass. For 
instance, compare a flowering Mexican with a Colombian that doesn't. The 
Colombian may be better because the difference in varieties is so great. On the 
other hand, the Mexican may be better because it is flowering and has reached 
its full potential. 
Intercropping
It is well-known that certain plants may be antagonistic to other species of 
plants, and that there are also beneficial relationships between species. 
Cannabis is known not to grow well among spinach 222. Although tomatoes and 
tobacco have been recommended as crops to avoid when growing marijuana, because 
of pests and diseases that these plants may harbor 67, marijuana grows very well 
in healthy tomato patches. Growers have also commented on how well marijuana 
grows when planted with corn, sugarcane, and beets. 



Chapter 16
INSECTS AND OTHER PESTS
Outdoors, where it functions as part of an ecological system, marijuana is less 
susceptible to insect attacks than it is indoors. In an outdoor environment, 
insects are subject to the vagaries of the weather, food supply, and predators. 
And marijuana grows so fast that insects usually do little damage. Plants, plant 
eaters, and predators usually maintain an equilibrium which minimises damage. 
But this balance is disturbed by tilling and gardening, and may take a while to 
re-establish itself. 
The soil surrounding your plants may be teeming with insects, and it would be 
unnatural not to see some on your plants. Most insects do not eat marijuana. The 
few that do are the food which helps to keep a small population of their 
predators alive. Insects in the garden need to be controlled only when there is 
a real threat of damage. 
Marijuana is most vulnerable in its early stages. After the plant increases 
production of the cannabinoids and resins at the eighth or ninth week, most 
insects are repelled. When the plants are small, an occasional munch affects a 
relatively larger part of the plant. That same bite affects a relatively smaller 
part when the plant is larger. 
The insects that infect marijuana indoors - aphids, mealy bugs, mites, and 
whiteflies - do best in humid conditions with constantly warm temperatures. 
Outdoors they rarely inflict much damage on marijuana. The pests that are most 
likely to damage marijuana are leafhoppers, treehoppers, cucumber beetles, 
thrips, flea beetles, several kinds of caterpillars, snails, and slugs. The 
younger the plants are, the more susceptible they are to attack. Your prime goal 
is to protect the plants during the first two vulnerable months. You need to 
keep the pest population low, so that the damage is relatively light. The pests 
don't have to be eliminated, only kept under control. 
There are many ways to keep pests from damaging your crops. These fall into one 
or more of several categories: biological control; capture traps and barriers; 
home remedies; and chemical insecticides. 
16.2 Biological Control
The theory behind biological controls is that methods for control of pests can 
be found within nature. These methods are safer to humans and less damaging to 
the environment than commercial insecticides. Gardeners have many forms of 
biological control at their disposal, including companion planting, use of 
predators, and sprays made from plant extracts or ground-up insects. 
Companion Planting
Some plants, including marijuana in its later stages, produce resins or essences 
which repel or kill plant pests. Some of them are general repellents that affect 
a broad range of plant pests; others affect specific species. Generally, the 
heavily scented plants, such as spices, mints, and other herbs, are most likely 
to have these qualities. 
Some of the more familiar plants used to protect gardens are the Alliums, or 
onion family, with garlic, chives, green onions, and other oniony-type plants as 
members. This group repels a broad range of plant pests such as aphids, spider 
mites, flea beetles, potato bugs, bean beetles, and many other insects, as well 
as rabbits and some deer. They are easily planted around the garden or between 
the marijuana plants. Just plant onion bulbs or the cloves from a garlic bulb so 
that the top of the bulb is about one inch deep. One garlic bulb yields quite a 
few cloves; so a large garden requires only a few bulbs. 
Geraniums are reputed to repel leafhoppers and many kinds of beetles. These 
plants prefer a dry soil, thrive in full light, and usually grow two feet tall. 
Geraniums should be interspersed with the marijuana, or potted geraniums can be 
set out if problems develop. Tansy (Tanaetum vulgare) is a tall, fragrant, woody 
perennial which grows five feet tall. It protects against cut-worms, beetles, 
cucumber beetles, and other eaters and borers. 
Mints repel many insects and are sometimes used as mouse repellents. They are 
especially useful for the control of the flea beetle. They thrive in semi-shaded 
areas with rich soil. 
Marigolds can be planted to eliminate nematodes. They are fast-growing annual 
plants which flower profusely. They come in many varieties, ranging in height 
from six to 30 inches. They grow in a wide range of soils and do best in the 
sun. The scented varieties - usually nonhybrids - offer the most protection. 
All companion plants must be planted close to the plants to be protected, since 
their repellent qualities spread only a short distance beyond their 
circumference. They are effective when they are planted before the damage is 
apparent, and offer long-tern protection. They are used when a pest is expected. 
For instance, growers in the San Francisco Bay Area expect rose leafhoppers to 
attack their plants. Since geraniums grow in the area as perennial plants, some 
growers plant them permanently in the garden. As the geraniums develop into 
small bushes, the hoppers leave, never to return. 
Predators
Many of the insects in your garden are called beneficials, because they perform 
a useful service in the garden. Some of them eat decaying matter; others help in 
the pollination process; and some pry on insects which damage crops. Almost 
everyone is familiar with the ladybug, which eats aphids and insect eggs and has 
a voracious appetite. They are available commercially by the pint. The praying 
mantis eats slow-moving insects. When it first hatches, it starts out on aphids 
and mites. But as it grows larger, it eats bigger insects and worms. Mantis-egg 
cases are foam-like, straw-coloured masses which contain 100 to 300 eggs. These 
cases are sold commercially but can also be found in the late fall in bushy 
areas. Another insect which is sold commercially as a plant protector is the 
green or brown lacewing. It has golden eyes, looks fragile, and flies 
erratically. But in their larval state, lacewings eat thrips, mites, caterpillar 
eggs, scale, leafhopper nymphs, aphids, and mealybugs. The trichogamma wasp is 
an egg parasite which lays its eggs in the eggs of over 200 species of insects, 
including many moths and butterflies which hatch into worm pests. Cryptolaemus 
is used to destroy mealybugs. Adults are released when mealybugs appear in the 
spring. They seek out the mealybug colonies and lay their eggs. When the eggs 
hatch the larvae wander around the infested area and eat the young mealybugs. 
The use of commercially bred or gathered predators is most feasible in large 
gardens or fields. The insects may not have much effect on small gardens, since 
they wander off to find food and may never return. Try to buy from manufacturers 
who intentionally do not feed their product before shipping. Hungry predators 
are more likely to stay and eat the pests. 
Insects are just one groups of predators. Birds such as purple martins, robins, 
blue jays, chickadees, and even starlings and English sparrows eat large 
quantities of insects and other small pests. They can be attracted to the garden 
by placing a feeder, bird houses, and water in the area. When plants get larger, 
some gardeners let chickens, ducks, or geese run through the garden. In a short 
time, they pick it clean of pests and weeds. Reptiles and amphibians, including 
frogs, toads, snakes, lizards, and turtles, all eat garden pests and should be 
encouraged to make a home in the garden. 
Homemade Repellents and Insecticides
Another way to control garden pests is to make sprays from plants which repel 
insects by using a juicer or blender or by baking a tea. Ingredients can be 
found in most kitchens. Chile pepper, garlic, coffee, horseradish, radish, 
geranium, and tobacco are the usual mainstays of herbal sprays, although most 
strong-smelling herbs and spices have some repellent qualities. Many gardeners 
experiment to see what works in their garden. For instance, if an insect which 
bother marijuana stays clear of a nearby weed, a tea or blended spray made form 
that plant may control the pest. But try it on only one plant (or part of a 
plant) first, because the spray may also be harmful to the marijuana. 
Garlic is probably the most popular ingredient for general-purpose sprays made 
from kitchen ingredients. A typical formula is to soak three ounces of chopped 
or minced garlic in a covered container of mineral oil for a day. Then, slowly 
add a pint of lukewarm water in which a quarter ounce of real soap (Ivory will 
do) has been dissolved. Stir and let stand several hours, than strain. Use as a 
concentrate, adding between 20 to 100 parts water to one part concentrate. 
Other recipes call for boiling the garlic or for grinding or juicing it. Some 
brewers add other spices to the basic formula. One recipe calls for one clove 
garlic, three cayenne peppers, one onion, a quarts ounce of soap, and sufficient 
water to blend. Let it sit for three or four days before using, and use one part 
concentrate to 20 parts water. Homemade tobacco teas are sometimes used as 
insect sprays. Use one cigarette in a quart of water. Let it brew 24 hours 
before using. 
Snails and slugs are attracted by yeast solutions, which are easily prepared 
from cooking yeast, sugar, and water. This is also why gardeners have success 
trapping these leaf munchers in bowls of stale beer. Place deep-sided containers 
at the soil level. The pests slide in and drown. 
Gardeners should not overlook handpicking as a viable method of pest control. 
The foot or a quick thumb and forefinger can eliminate large numbers of pests 
and can keep a small garden pest-free. Collect the bugs and drop them in a tin 
can with some alcohol to kill them. Early morning is the best time to collect 
pests, since they are slower-moving until the sun warms them. 
Snails, slugs, earwigs, and some other insects gather in cool, moist areas 
during the heat of the day. By providing just such a space in a garden, many of 
these pests can be located and destroyed. Place pieces of cardboard or boards 
around the garden; look under them each day. 
Home Remedies
Gardeners and farmers have discovered and invented ingenious ways to control 
insects without harming the environment. Some of the more popular ones are 
listed here, but there are many more, each suited to a particular situation. 
Soap and water is an effective control measure for mealybugs, mites, leafhoppers 
(nymph stage), leaf miners, and aphids. Simply wash the plants thoroughly with a 
solution of two tablespoons of soap dissolved in a gallon of water. Rinse the 
soap off thoroughly. (Some growers feel that the addition of kerosene or alcohol 
makes the solution more effective, but these can harm the plants and dissolve 
THC.) This treatment does not eliminate all of the pests, and may need to be 
repeated weekly, but it does keep them under control. 
Sprays are sometimes made from healthy insects, which are caught, ground up, and 
then sprayed back onto the plants. When the pests come in contact with the 
spray, they become infected with the pathogen and get sick. This method is very 
effective, and is considered safe, but it is not easy to capture sick insects. A 
variation in this technique was described in the October 1976 Organic Gardening 
and Farming Magazine, in which a spray was made from healthy insects. In a 
followup article in the May 1977 issue, the authors theorised that any 
population of insects contains pathogens. If enough insects are collected, some 
of them are sure to be sick, and they contain enough germs to spread the 
disease. To make an insect spray, capture about a hundred pests. (Make sure not 
to include any beneficial insects or the spray may also work against them.) 
Using a blender, mix them with a cup of spring water, strain, and dilute with 
enough water to spray your garden. 
Whenever making or storing sprays, use a glass container. Metal or plastic ones 
may react with the chemicals that the liquids contain. 
Another home remedy for the control of mites and aphids is a mixture consisting 
of a half cup of milk in four cups of wheat flour, added to five gallons of 
water. When it is sprayed on the undersides of the leaves, it suffocates the 
insects and then flakes off as it dries. 
Some growers use mulches to control insects. Cedar chips repel beetles, moths, 
mites, and mealybugs. Aluminium foil is used for aphid and thrip control on 
small plants; the reflected light disorients them and they do not land on the 
plants. A sprinkling of cream of tartar eliminates ants, and boric acid kills 
roaches. Sulfur powders, available at nurseries, are used to control mites and 
fungus infections. 
Organic Insecticides
Pyrethrum, rotenone, and ryania are effective insecticides which come as powders 
(dusts) or sprays. They are concentrated form of naturally occurring plant 
substances, and are considered harmless to warm-blooded animals when used as 
directed. 
Ryania, which is found in the roots of a tropical shrub, is most effective 
against chewing insects, worms, and larvae, which it incapacitates, rather than 
kills. 
Rotenone is a general-purpose insecticide with little residual effect; that is, 
it breaks down soon after application, and is therefore one of the safest 
insecticides. Two or three dustings during the seedling stages afford protection 
against most insects and bugs. 
Pyrethrum is one of the most powerful natural insecticides, and is effective 
against a wide range of pests. It is also relatively nontoxic to bees and 
ladybugs. Pyrethrums are found in the pyrethrum plant as well as in 
chrysanthemums. They are non-persistent, and in small doses may make the insects 
sick without killing them. These insecticides are available at many nurseries 
and may provide the surest, easiest form of protection against serious insect 
attack. 
Barriers and Traps
In gardens and small farms, insects and other pests are sometimes controlled by 
the use of traps and barriers that prevent them from reaching the marijuana. 
When the plant are young, they can be protected from cutworms, caterpillars, 
snails, and slugs by a collar that is buried an inch into the ground and is six 
inches high. Some growers face it with aluminium foil, which many insects seem 
to dislike. One ingenious grower painted collars with molasses to capture the 
crawlers. She also caught a significant number of leafhoppers. Commercial 
stickums such as Tanglefoot can also be used to trap insects. 
Snails, slugs, and some crawling insects are repelled by a border perimeter of 
lime, potash (wood ash), sulfur, sharp sand, or cinders. Place a thin layer, six 
inches wide, around the perimeter of the garden, or around each plant. Flea 
beetles and some other flying insects are repelled by wood ashes dusted on the 
leaves. The powders are water-soluble; so they should be replaced after a heavy 
rain. Crawling pests sometimes have a hard time reaching plants grown in 
containers or raised beds. 
Flying insects, such as leaf and treehoppers, can be prevented from getting to 
plants by barriers made from cheesecloth. Other growers place cardboard sticky 
with glue between plants, and then shake the plants. The cardboard catches a 
good proportion of them. One innovative grower in Palo Alto, California, placed 
a furniture crate, with the top cut off and with Tanglefoot spread on the 
inside, around each of his six plants. He said that by shaking the plants, he 
eliminated leafhoppers in four days. 
16.3 Chemical Insecticides
Insecticides were developed as an easy way to control pests. They have an 
immediate dramatic effect, but the long-range damage that they do to the entire 
ecological system is sometimes overlooked. The chlorinated hydrocarbons, such as 
DDT, DDC, Aldrin, Kelthane, and Dieldrin, were the most dangerous commercial 
insecticides. They affect warm-blooded animals and are no longer available. (In 
no case should any of these by used.) 
Diazinon, Sevin, and Malathion are three insecticides which are often soil in 
nurseries to protect vegetable crops. They are considered safe for warm-blooded 
animals and have a limited residual effect, since they break down in a few days. 
But these insecticides are not too selective and may kill beneficials as well as 
pests. Sevin is the most toxic and kills the widest range of insects, including 
bees. 
These chemicals come as sprays, powders, and baits, formulated for specific 
pests. They should be used only when an intolerable situation has developed. 
Plants should be harvested only after the required safety period has passed 
since application. This period is from two to 35 days, and is specifically 
listed on all insecticides that can be safely used. Insecticides should be used 
and handled carefully, following instructions, wearing protective clothing, with 
no children or pets around. It is advisable to use a mask when applying dusts 
and to work upwind. 
16.4 Common Pests
Cucumber Beetles
Cucumber beetles are about a quarter-inch long and look a lot like ladybugs. 
There are several species of cucumber beetles. The striped beetle is found east 
of the Rocky Mountains. It is yellow, has two or three black stripes running 
down its back, and has a black head. The spotted cucumber beetle has a 
yellow-green back with 11 or 12 black spots and a black head. There are related 
species, such as the banded cucumber beetle, throughout the United States. The 
larvae of all varieties are white, turning brownish at the ends, slender, about 
one-third inch long. 
Cucumber beetles do the most damage in the early spring, when the adults come 
out of hibernation and begin to eat the new growth and leaves. These leaf-eating 
adults damage young marijuana, especially when there is a scarcity of other 
food. They also transmit bacterial diseases and viruses to the plants. Within a 
few weeks after they come out of hibernation, they lay their eggs at the base of 
plant roots. The larvae of the striped cucumber beetle feed only on melon- and 
cucumber-type plant roots. The spotted-beetle larvae are fond of corn, and are 
known as the "Southern cornroot worm" in some places. 
The best way to prevent cucumber-beetle attacks is to keep the areas that you 
plant isolated from corn and melon plantings. Heavy mulching or tilling destroys 
the pests when they are hibernating. Late plantings minimise damage inflicted by 
cucumber beetles. 
Cucumber beetles can be controlled by use of Rotenone or Malathion. Dust several 
times during seedling growth. These beetles are also prey to many insects, 
including the common garden soldier beetle, predator flies, wasps, and 
nematodes. Hand picking is also an effective control for cucumber beetles. 
Thrips
Thrips are slender, yellow or brownish, winged insects about 1/25 inch long. 
They have fragile wings which keep them aloft while they are blown by the wind. 
Thrips have a cone-shaped mouthpart, which they use to cut stems in order to 
suck plant juices. The larvae look like adults, but are smaller and wingless. 
Most thrips feed on a range of plants, especially onion and other bulbs, and 
marijuana is at most a marginal part of their diet. A well-cultivated marijuana 
plant can outgrow and damage that thrips are likely to inflict. 
Thrips hibernate in plant debris during the winter and begin sucking in early 
spring. They lay eggs during warm weather, and can produce a new generation 
every two weeks. Since thrips eat a varied diet, keeping the garden area clear 
of weeds is an effective control. Thrips can also be controlled by turning 
debris under, so that their nesting sites are destroyed. 
Thrips can be controlled by use of tobacco sprays. Rotenone, or Malathion. 
Aluminium-foil mulches are effective thrip repellents. The light reflected from 
the foil confuses their sense of direction. 
Flea Beetles
There are many species of flea beetles. The adults range in size between 
one-twentieth and one-fifth of an inch, and are usually black or metallic green 
or blue. They are called flea beetles because they use their enlarged hind legs 
to jump like fleas when disturbed. Many flea beetles are host-specific, and 
probably only a few species munch on marijuana. 
Flea beetles hibernate in plant debris. By ploughing the debris under, their 
hibernation places are eliminated, and there should be few pests the following 
spring. Flea beetles are repelled by a mixture of equal parts of wood ashes and 
limestone sprinkled on foliage every few days. Containers of the mixture may 
also by placed around the plants. Garlic sprays also repel flea beetles. The 
chemical poisons used specifically for flea beetles are stomach poisons, which 
break down slowly and may not be safe to inhale. Home remedies are best for flea 
beetles. 
16.5 Vertebrate Pests
Mammals Until it develops a hard fibrous main stem, usually at about two months, 
the young marijuana plant attracts rodents, including mice, rabbits, moles, 
squirrels, groundhogs, and rats, as well as raccoons. Cats are probably the best 
means of rodent control. They stalk small prey, go after any movement, and are 
active at night, when most of these animals forage. Young plants are often 
protected from rodents by placing a coffee can with top and bottom removed 
around each plant. When the plants get bigger, they can be protected from 
rabbits and other animals with a wire fence three feet in height. A double layer 
of one-inch chicken wire is most effective. But many animals can climb or 
burrow; so more ingenious methods are needed to protect the plants. Rodents, 
especially moles, are repulsed by castor beans and castor oil. A formula that 
gardeners sometimes use is two parts castor oil, one part detergent, mixed to a 
consistency of shaving cream in a blender. Use a tablespoon of concentrate per 
gallon of water. Spray or mist the solution on the plants. 
Rabbits shy away from blood, bloodmeal, and tankage. To use, sprinkle the powder 
around the perimeter of the plot in a band about a foot wide. They can also be 
mixed into a concentrated solution and applied as a spray. However, the small of 
blood may attract mongoose or other predators, which dig up the garden in search 
of flesh. Noise from radios, chimes, and bells deter some animals, and human 
smalls such as hair and urine may also deter some animals. In dry areas, a 
half-filled bucket of water is an effective rodent trap. The animals fall in and 
drown. 
Deer seem to go out of their way to munch on tender marijuana leaves, but 
generally don't bother marijuana after it has grown for a few months. Gardeners 
and farmers use many ingenious techniques to keep them away from crops. Sturdy 
fences are the best deterrent. The fences should be about 10 feet high: the 
bottom five feet should be made up of single strands of wire string at two-foot 
intervals. The wire strands prevent deer from jumping the fence. Some growers 
use fresh blood, dried blood, or bloodmeal to deter them, placing it in either 
powder or liquid form around the perimeter of the garden. Other growers claim 
that human hair, or manure from predators such as wolves, bears, lions, and even 
dogs, keeps them out. Lion urine (glans extract) is available commercially, and 
is said to be an effective deterrent against many animals. {Figure 73. Tin cans 
protect against cutworms and many other plant eaters.} 
{Figure 74.  Fat rat munching marijuana.}
{Figure 75.  Problem solved; or, never underestimate the power of a peanut.
{Rat caught in mouse trap.}}
Birds
On the whole, birds are beneficial, rather than harmful, in the garden. Most of 
the common species, including English sparrows, robins, swallows, wrens, 
finches, bluejays, bluebirds, and starlings, eat insects and other garden pests 
as a substantial portion of their diet. The only time that birds may be harmful 
is during planting, when they sometimes feed on the planted seed. The main 
culprits seem to be starlings, sparrows, and crows. They can be kept off the 
planted areas physically, by means of plastic netting or fencing, which is sold 
commercially for the purpose, or by using scarecrows, aluminium strips, or noise 
makers. Once the plants have germinated, birds are no longer a threat and should 
be encouraged to nest in the area, since they are an ideal biological control 
for plant pests. 



Chapter 17
GENETICS AND SEX IN CANNABIS
Sex is an inherited trait in Cannabis, and can be explained in much the same 
terms as human sexuality can. Like a human being, Cannabis is a diploid 
organism: its chromosomes come in pairs. Chromosomes are microscopic structures 
within the cells on which the genes are aligned. Cannabis has 10 pairs of 
chromosomes (n=10), for a total of 20 chromosomes (2m=20). 
One pair of chromosomes carries the primary genes that determine sex. These 
chromosomes are labelled either X or Y. Male plants have an XY pair of sex 
chromosomes. Females have XX. Each parent contribute one set of 10 chromosomes, 
which includes one sex chromosome, to the embryo. The sex chromosome carried by 
the female ovule can only be X. The one carried by pollen of the male plant may 
be either X or Y. From the pollen, the embryo has a 50/50 chance of receiving an 
X, likewise for Y; hance, male and female progeny appear in equal numbers (in 
humans, the sperm carries either an X or a Y chromosome.) 
17.2 Flowering
Male Plant
Under natural light, males usually start to flower from one to four weeks before 
the females. Where the photoperiod is artificially controlled, as with electric 
lights, males respond quickly (in about a week) to a change to short 
photoperiods and usually show flowers sooner than the females. 
Male flowers develop quickly, in about one to two weeks on a vigorous plant, not 
uniformly. Scattered flowers may open a week or more before and after the 
general flowering, extending the flowering stage to about four weeks. 
The flowering stage continues to demonstrate the male's tall, relatively sparse 
growth. Most of the flowers develop near the top of the plant, well above the 
shorter females. The immature flower buds first appear at the tips of the main 
stem and branches. Then tiny branches sprout from the leaf axils, bearing 
smaller clusters of flowers. The immature male flowers are closed, usually 
green, and develop in tight clusters of knob-like buds. The main parts of the 
male flowers are five petal-like sepals which enclose the sexual organs. As each 
flower matures, the sepals open in a radiating pattern to reveal five pendulous 
anthers (stamens). 
Inside the ovoid, sac-shaped anthers, pollen grains develop. Initially, pollen 
sifts through two pores near the top of the anther; then, starting from the 
pores, longitudinal slits slowly open (zipperlike) over the course of a day, 
releasing pollen to the wind. Once a flower sheds pollen, it shortly dies and 
falls from the plant. Normally, male plants begin to die one to two weeks after 
the bulk of their flowers have shed pollen. Healthy males may continue to flower 
for several more weeks, but secondary growth seldom has the vigour of initial 
bloom. 
Female Plant
The female plant generally starts to flower later than the male, under either 
natural light or an artificially controlled photoperiod. Female marijuana plants 
flower when the average daily photoperiod is less then about 12 to 13 hours. 
However, some varieties and individuals may flower with a photoperiod of over 14 
hours. Some Colombian varieties may not respond until the photoperiod falls 
below 12 hours for a period of up to three weeks. 
The duration of flowering also depends on the particular rhythm of the variety, 
as well as growing conditions, and whether or not the plant is pollinated. 
Within these variables, females maintain vigorous growth and continue to rapidly 
form flowers for a period that ranges from 10 days to about eight weeks. 
Females generally do not grow much taller during flowering. Growth emphasises a 
"filling out," as flower clusters develop from each leaf axil and growing tip. 
Normally, the flowers arise in pairs, but the pairs form tight cluster of 10 to 
over 100 individual flowers that are interspersed with small leaves. These 
clusters are the "buds" of commercial marijuana. Along the top of the main stem 
and vigorous branches, "buds" may form so thickly that the last foot or more of 
stem is completely covered. Usually the leaves that accompany the flowers tend 
toward simpler structure, until each leaf has one to three blades. {Figure 76. 
Female in full bloom.} 
The visible parts of the female flower are two upraised stigmas, one-quarter to 
one-half inch long, usually white or cream, sometimes tinged with red, that 
protrude from a tiny, green, pod-shaped structure called the floral bract. This 
consists of modified leaves (bracts and bracteoles) which envelop the ovule or 
potential seed. The mature bract is a tiny structure, about 1/8 inch across and 
1/4 inch long. When fertilised, a single seed begins to develop within the 
bract, which then swells until it is split by the mature seed. 
Bracts are covered more densely with large resin glands than is any other part 
of the plant, and are the most potent part of the harvest. Resin glands may also 
be seen on the small leaves that are interspersed among the flowers. 
The differences between male and female Cannabis become more apparent as the 
plants mature. The same can be said of the differences between varieties. Often, 
two varieties may appear to be similar, until they actually flowers and fill out 
to different forms. These appear in many ways: some varieties maintain opposite 
phyllotaxy with long internodes throughout flowering; bud sizes vary from about 
one-half inch to about three inches, with a norm of about one to two inches; 
buds may be tightly arranged along the stem, yielding a "cola" two feet long and 
four inches thick; and some varieties only form buds along their main stem and 
branch tips, with a few "buds" forming along the branches. 
{Figure 77.  Upper left: Buds form thickly into colas along the top of
the main stem and branches (full bloom).  Upper right: A cola about two
feet long.  Lower left: A huge leafy cola.  Lower right: Long, slim buds
form late in the year when light is weak.  (these four colas are from
Mexican plants.}
When a female is well-pollinated, growth slows and the plant's energy goes into 
forming seeds and thus into the continuation of the species. Some plants (but 
only the more vigorous ones) will renew flowering even when pollinated. Females 
that are not well-pollinated continue to form flowers rapidly. This extends the 
normal flowering period, of 10 days to four weeks, up to eight weeks or more. 
Individual flowers are pollinated by individual pollen grains. In a matter of 
minutes from its landing on a stigma, the pollen grain begins to grow a 
microscopic tube, which penetrates the stigma and reaches the awaiting ovule 
wrapped within the bracts. The pollen tube is a passageway for the male's 
genetic contributions to the formation of the embryo (seed). 
The union of the male and female complements of genes completes fertilisation 
and initiates seed formation. The stigmas, having served their purpose, shrivel 
and die, turning rust or brown colour. On a vigorous female, the seeds reach 
maturity in about 10 days. When growing conditions are poor, the seed may take 
five weeks to ripen to full size and colour. Naturally, all the flowers do not 
form, nor are they pollinated at the same time - and there will be seeds that 
reach maturity weeks before others do. Although each flower must be individually 
fertilised to produce a seed, a single male plant can release many millions of 
pollen grains. A large female plant can produce over 10,000 seeds. 
17.3 Sexual Variants in Cannabis
Cannabis has been studied for many years because of its unusual sexuality. 
Besides the normal dioecious pattern, where each plant bears exclusively male or 
female flowers, it is not uncommon for some plants to have both male and female 
flowers. These are called hermaphrodites, or monoecious plants, or intersexes. 
Hermaphroditic plants form normal flowers of both sexes in a wide variety of 
arrangements, in both random and uniform distributions. 
Natural Hermaphrodites
Some hermaphrodites seem to be genetically determined (protogenous). That is, 
they naturally form flowers of both sexes given normal growing conditions. 
Possibly genes carried on the autosomes (the chromosomes other than the sex 
chromosomes) modify the normal sexual expression. Monoecious varieties have been 
developed by hemp breeders in order to ensure uniform harvests. 
It is also possible that these particular are polyploid, which means they have 
more than the usual two sets of chromosomes. This kind of hermaphrodite may have 
XXY (triploid), or XXYY or XXXY (tetraploid) sex chromosomes. However, no 
naturally occurring polyploids have ever been verified (by observation of the 
chromosomes) in any population of Cannabis. Polyploids have been induced in 
Cannabis by using mutagens, such as the alkaloid colchicine. 
Whatever then genetic explanation may be, one or more of these natural 
hermaphrodites may randomly appear in any garden. They are sometimes 
faster-maturing, have larger leaves, and are larger in overall size than their 
unisexual siblings. They usually form flowers of both sexes uniformly in time 
and distribution, and in some unusual patterns. For example, from Mexican seed, 
we have seen a plant on which separate flowering cluster consisted of both 
female and male flowers: and upper section of female flowers had upraised 
stigmas, and a lower section of male flowers dangled beneath the female flowers. 
In other plants from Mexican seed, the growing tips throughout the plant have 
female flowers; male flowers sprout from the leaf axils along the main stem and 
branches. Plants from "Thai" seed sometimes form male and female flowers on 
separate branches. Branches with female flowers tend to predominate, but 
branches having mostly male flowers are located throughout the plant. 
Abnormal Flowers, Intersexes, Reversals
Gender is set in the new plant at the time of fertilisation by its inheritance 
of either the X or the Y chromosome from the male (staminate) plant. With 
germination of the seed, the environment comes into play. Heritage sets the 
genetic program, but the environment can influence how the program runs. (Sexual 
expression in Cannabis is delicately balanced between the two.) The photoperiod, 
for example, controls the plant's sequence of development. Also, the plant's 
metabolism and life processes are dependent on growing conditions. When the 
environment does not allow a balance to be maintained, the normal genetic 
program may not be followed. This is mirrored by abnormal growth or sexual 
expression. 
{Figure 78. Upper left: Abnormal flowers.  Lower left: Male flowers on a
female plant.  Upper right: Sexes on separate branches.  Lower right: Male
flower in female bud (reversing).}
Abnormal Flowers
Abnormal sexual expression includes a whole range of possibilities. Individual 
flowers may form abnormally, and may contain varying degrees of both male and 
female flower parts. For instance, a male flower may bear a stigma; or an anther 
may protrude from the bracts of a female flower. Abnormally formed flowers are 
not often seen on healthy plants, although if one looks hard enough, a few may 
be found in most crops. When many of the flowers are abnormal, an improper 
photoperiod (coupled with poor health) is the most likely cause. Abnormal 
flowers sometimes form on marijuana grown out of season, such as with winter or 
spring crops grown under natural light. 
Intersexes and Reversals Much more common than abnormally formed flowers is for 
the plant's sex to be confused. One may find an isolated male flower or two; or 
there may be many clusters of male flowers on an otherwise female plant, or vice 
versa. These plants are called intersexes (also hermaphrodites or monoecious 
plants). Intersexes due to environment causes differ from natural hermaphrodite 
in having random distributions and proportions of male and female flowers. In 
more extreme cases, a plant may completely reverse sex. For example, a female 
may flowers normally for several weeks, then put forth new, sparse growth, 
typical of the male, on which male flowers develop. The complete reversal from 
male flowering to female flowering also happens. 
All other things being equal, the potency of intersexes and reversed plants is 
usually less than that of normal plants. If there are reversals or intersexes, 
both of the sexes will usually be affected. Female plants that reverse to male 
flowering show the biggest decline. Not only is the grass less potent, but the 
amount of marijuana harvested from male flowers is negligible compared to the 
amount of marijuana that can be harvested from a normal female. Plants that 
change from male to female flowering usually increase their potency, because of 
the growth of female flower bracts with their higher concentration of resin. 
Female flowers on male plants seldom form as thickly or vigorously as on a 
normal female. Between the loss in potency and the loss in yield because of 
females changing to males, a crop from such plants is usually inferior, in both 
yield and potency, to one from normal plants. 
Environmental Effects
Many environmental factors can cause intersexes and sexual reversals. These 
include photoperiod, low light intensity, applications of ultraviolet light, low 
temperatures, mutilation or severe pruning, nutrient imbalances or deficiencies, 
senescence (old age), and applications of various chemicals (see bibliography on 
sex determination). 
The photoperiod (or time of planting using natural light) is the most important 
factor to consider for normal flowering. In 1931, J. Schaffner (105) showed that 
the percentage of hemp plants that had confused sexual characteristics depended 
on the time of year they were planted. Normal flowering (less than five percent 
of the plants are intersexes) occurred when the seeds were sown in May, June, or 
July, the months when the photoperiod is longest and light intensity is 
strongest. When planted sooner or later in the year, the percentage of 
intersexuals increased steadily, until about 90 percent of the plants were 
intersexual when planted during November or early December. 
Marijuana plants need more time to develop than hemp plants at latitudes in the 
United States. Considering potency, size, and normal flowering, the best time to 
sow for the summer crop is during the month of April. Farmers in the south could 
start the plants as late as June and still expect fully developed plants. 
If artificial light is used, the length of the photoperiod can influence sexual 
expression. Normal flowering, with about equal numbers of male and female 
plants, seems to occur when the photoperiod is from 15 to 17 hours of light for 
a period of three to five months. The photoperiod is then shortened to 12 hours 
to induce flowering. With longer photoperiods, from 18 to 24 hours a day, the 
ratio of males to females changes, depending on whether flowering is induced 
earlier or later in the plant's life. When the plants are grown with long 
photoperiods for six months or more, usually there are at least 10 percent more 
male then female plants. When flowering is induced within three months of age, 
more females develop. Actually, the "extra" males or females are reversed 
plants, but the reversals occur before the plants flower in their natural 
genders. 
Some plants will flower normally without a cutting of the photoperiod. But more 
often, females will not form thick buds unless the light cycle is cut to a 
period of 12 hours duration. Don't make the light cycle any shorter than 12 
hours, unless the females have not shown flowers after three weeks of 12-hour 
days. Then cut the light cycle to 11 hours. Flowers should appear in about one 
week. 
Anytime the light cycle is cut to less than 11 hours, some intersexes or 
reversed plant usually develop. This fact leads to a procedure for increasing 
the numbers of female flowers indoors. The crops can be grown for three months 
under a long photoperiod (18 or more hours of light). The light cycle is then 
cut to 10 hours. Although the harvest is young (about five months) there will be 
many more female flower buds than with normal flowering. More plants will 
develop female flowers initially, and male plants usually reverse to females 
after a few weeks of flowering. 
Of the other environmental factors that can affect sexual expression in 
Cannabis, none are as predictable as the photoperiod. Factors such as nutrients 
or pruning affect the plant's overall health and metabolism, and can be dealt 
with by two general thoughts. First, good growing conditions lead to healthy 
plants and normal flowering: female and male plants occur in about equal 
numbers, with few (if any) intersexes or reversed plants. Poor growing 
conditions lead to reduced health and vigour, and oftentimes to confused sex in 
the adult plant. Second, the age of the plants seems to influence reversals. 
Male plants often show female flowers when the plant is young (vigorous) during 
flowering. Females seven or more months old (weaker) often develop male flowers 
after flowering normally for a few weeks. 
Anytime the plant's normal growth pattern is disrupted, normal flowering may be 
affected. For instance, plant propagated from cuttings sometimes reverse sex, as 
do those grown for more than one season. 
17.4 Sexing the Plants
The female plant is more desirable than the male for marijuana cultivation. The 
female flowering clusters (bus) are usually the most potent parts of the 
harvest. Also, given room to develop, a female generally will yield twice as 
much marijuana as her male counterpart. More of her weight consists of 
top-quality buds. 
Because the female yields marijuana in greater quantity and sooner you can 
devote your attention to nurturing the females. Where space is limited, such as 
in indoor gardens and small outdoor plots most growers prefer to remove the 
males as soon as possible, and leave all available space for the females. To 
harvest sinsemilla (seedless female buds), you must remove the male plants 
before they mature and release pollen. 
Differences in the appearance of male and female Cannabis become more apparent 
toward maturation. During the seedling stage, gender is virtually impossible to 
distinguish, although in some varieties the male seedling may appear slightly 
taller and may develop more quickly. 
We know of no way to discover gender with any certainty until each plant 
actually forms either pollen-bearing male flowers or seed-bearing female 
flowers. However, certain general characteristics may help. Using guidelines 
like the following, growers who are familiar with a particular variety can often 
predict gender fairly accurately by the middle stage of the plant's life. 
Early Vegetative Growth
After the initial seedling stage, female plants generally develop more complex 
branching than the male. The male is usually slightly taller and less branched. 
(Under artificial light, the differences in height and branching are less 
apparent throughout growth.) 
Some plants develop a marked swelling at the nodes, which is more common and 
pronounced on female plants. 
Middle Vegetative Growth
In the second to fourth months of growth, plants commonly form a few isolated 
flowers long before the actual flowering stage begins. These premature flowers 
are most often found between the eighth and twelfth nodes on the main stem. 
Often they appear near each stipule (leaf spur) on several successive nodes, at 
a distance two to six nodes below the growing tip. These individual flowers may 
not develop fully and are often hard to distinguish as male or female flowers. 
The fuzzy white stigmas of the female flower may not appear, and the male 
flowers seldom opens but remains a tightly closed knob. However, the male flower 
differs from the female; it is raised on a tiny stalk, and the knob is 
symmetrical. The female flower appear stalkless and more leaflike. 
The presence of premature female flowers does not assure that the plant is a 
female, but premature male flowers almost always indicate a male plant. 
Unfortunately, it is much less common for male plants to develop premature male 
flowers than for female flowers to appear on either plant. For example, in one 
garden of 25 mixed-variety plants, by age 14 weeks, 15 plants showed 
well-formed, premature female flowers with raised stigmas. Eight of these plants 
matured into females and seven became males. Only two plants showed premature 
male flowers and both of these developed into males. The eight remaining plants 
did not develop premature flowers or otherwise distinguishable organs until the 
actual flowering stage at the age of 21 weeks. From these eight, there were four 
females, three males, and one plant bearing both male and female flowers 
(hermaphrodite). It does seem, however, that plants bearing well-formed female 
flowers, on several successive node, usually turn out to be females. 
Preflowering
In the week or two prior to flowering and throughout flowering, many common 
marijuana varieties follow two general growth patterns which depend on gender. 
With these varieties, you can tell gender by the spacing between the leaves 
(internodes). For the female, the emphasis is on compact growth. Each new leaf 
grows closer to the last, until the top of the plant is obscured by tightly knit 
leaves. The male elongates just prior to showing flowers. New growth is spaced 
well apart and raises the male to a taller stature. This may by the first time 
the male shows its classic tall, loosely arranged profile. 
{Figure 79.  Premature flowers are found on the main stem next to the
leaf spurs. Upper left: Early female flower without stigmas. Lower left:
Undifferentiated (indistinguishable). Centre: Early male flower. Upper
and lower right: Well-formed female flowers on successive nodes usually
indicate a female.}
17.5 Sinsemilla
Sinsemilla ((The word "sinsemilla" comes from the Spanish, and means "without 
seeds." It is also spelled "sansimilla.")) is any marijuana consisting of 
seedless female flower buds. Sinsemilla is not a variety of marijuana; it is the 
seedless condition that results when the female flowers are not fertilised with 
pollen. 
In the United States, most sinsemilla comes in the form of Thai sticks that are 
imported from Southeast Asia and Japan. Thai sticks are made up of seedless buds 
wrapped around a sliver of bamboo or a long wooden matchstick. The buds, which 
may be on one or more stems, are secured with a hemp fibre wound around the 
stick. A growing amount of fine sinsemilla now comes from domestic sources, such 
as Hawaii and California. The grass is usually boxed or bagged with pure buds 
that are manicured (extraneous leaf removed). Infrequently sinsemilla comes from 
Mexico and, rarely, from Colombia. 
Sinsemilla has a reputation as high-potency marijuana, with a sweet taste and 
mild smoke. It doesn't have the harsh, gagging qualities of the usual Colombian 
and Mexican grasses. These qualities, however, have nothing to do with 
sinsemilla as such. The potency of any grass depends primarily on the variety 
and development of the plant, and the taste and mildness of the smoke depend on 
the condition of the plant when harvested and the cure. Heavily seeded grass can 
be as mild and sweet-smoking as sinsemilla when it is properly handled. 
When buying grass, remember that sinsemilla indicates a conscientious effort on 
the grower's part to bring you the best possible product. Sinsemilla is almost 
pure smoking material with no wasted weight in seeds. An ounce of sinsemilla has 
about twice as much smoking material as a typical seeded ounce. Also, any 
marijuana that is fresh, with intact buds, indicated less deterioration of 
cannabinoids. {Figure 80. Thai Sticks.} 
Sinsemilla is becoming a preferred form of grass with homegrowers, many of whom 
believe that a seedless female is more potent than a seeded one, reasoning that 
the plant's energy goes to the production of resin rather than seed. There seem 
to be no scientific studies on this point. Many experienced growers believe the 
difference is small, perhaps 10 percent. 
From observing the resin glands on the bracts, one sees that they continue to 
develop in size after pollination. Any difference from the unseeded state is not 
apparent. Whether pollination does in fact hamper or lessen resin production or 
potency is questionable. but the effect on the plant as a whole can be dramatic. 
Usually when the female is well-pollinated, growth noticeably slows, and the 
plant enters the last phase of life, which is seed set. Seed set is a period of 
incubation, in which the seeds grow and reach their mature state. New growth 
forms more slowly and lack the vitality of the bloom before pollination. The 
plant's reaction to pollination is relative. The more thoroughly pollinated the 
female is, the more pronounced the change in rhythm from vigorous to incubation. 
A plant on which only a few flowers have been fertilised continues to actively 
form flowers as sinsemilla. 
Not all plants react alike to pollination. When the weather is good and the 
plant vigorous, even a well-seeded plant may bloom a second or third time before 
the rate of growth starts a final decline. 
To put this in perspective, the main advantage to growing sinsemilla is that the 
plant remains in a flowering state for a longer period of time. Flowers may 
rapidly form for four to ten weeks. The flower buds develop larger and more 
thickly along the stems, yielding more top-quality grass (more buds) than in the 
seeded condition. 
Anyone can grow sinsemilla. Simply remove the male plants before they release 
pollen. Given a normal spring planting, males usually flowers in August and 
September, but may being to flower as early as mid-July. Under artificial 
lights, males sometimes flower after only three months, and before the grower 
has shortened the photoperiod. Even though the females are not flowering, remove 
the males from the room before any flowers open. Indoor, the pollen will collect 
as dust and can fertilise the females weeks later. 
Male flowers mature quickly, in about one to two weeks after the immature buds 
are first visible. Check each plant about twice a week to make sure you harvest 
all the males before any shed pollen. If you can't visit your garden 
consistently, then thin the garden, using the preceding section on "Sexing" as a 
guide. Even though you may not get all the males, the females will be more 
lightly seeded. Actually, even in carefully watched gardens, the females may 
have a few seeds. Pollination may come from on occasional male flower on a 
basically female plant, or a female may reverse and form male flowers. And 
pollen may come from a neighbour's garden, a problem that is becoming more 
common. But in practical terms, an occasional seed makes no difference. The 
female can form thousands of flowers, and when only a few are pollinated, there 
is little impact on the plant's growth. 



Chapter 18
PROPAGATION AND BREEDING
18.2 Producing Seeds
Marijuana is naturally prolific. It has been estimated that a single male plant 
can produce over 500 million pollen grains 41. A large female plant can bear 
tens of thousands of seeds. In nature, pollen is carried from the male flowers 
to the stigmas of the female flowers by air currents or the wind. Indoors or 
out, if the plants are simply left on their own, most gardens produce many more 
seeds than are needed for the next crop. 
Seeds usually become viable within two weeks after pollination, although they 
may not have developed good colour by this time. The colour can take several 
more weeks to develop, particularly indoors or late in the year, when the light 
is not as strong. Once seeds are plump, well-formed, and of a mature size, most 
of them will be viable. When seeds have also developed good colour, their 
viability should be over 90 percent. 
Pollination may also be carried out artificially. Pollen can be collected and 
the transferred to the female flowers with a cotton swab or artist's brush, or 
shaken directly over the flowers. Store pollen in a clean, open container and 
keep in a dry area at moderate temperature. Remove any flowers or vegetative 
matter from the pollen, because they encourage fungal attack. 
Once advantage of artificial pollination is that only the flowers on certain 
plants need be pollinated. This allows you to harvest most of your grass as 
sinsemilla, while developing seed on part of the plant. If you have only a few 
plants, pollinate a single branch, or perhaps only a few lower buds, in order to 
leaves the most potent buds seedless. 
A good way to insure a thorough pollination, and to avoid contaminating other 
females, is to loosely tie a transparent bag containing pollen directly over 
individual buds, branches, or whole plants. Shake the bag to distribute the 
pollen and carefully remove it from several hours to a few days later. 
To avoid contaminating a sinsemilla crop, you must remove any males from the 
garden before their flowers open. Males in pots can simply be moved to another 
area or room if you want to keep them growing. Male plants can complete 
development even in low light; so they do not need artificial light. Otherwise, 
the best procedure is to harvest the males intact by cutting them at their base 
after some flowers have formed distinct (but unopened) buds. Hang the whole 
plants upside down in a sheltered area where there is moderate light and where 
temperatures and humidity are not extreme. Place clean plates or sheet plastic 
beneath the plants to catch falling pollen. Generally there is enough stored 
water in the plant for the unopened flowers to mature and drop pollen. 
Well-formed flowers may open the next day. Usually all the flowers that are 
going to open will do so within two weeks. 
Pollen gradually loses viability with time, but pollen that is about three weeks 
old generally has sufficient viability for good seed production. However, the 
age of the pollen may influence the sex ratio of the next generation. 
For instance, in a 1961 study with hemp plants 97, the percentage of females in 
the next generation was 20 percent higher than in the control plants (natural 
pollination) when pollen 14 to 17 days old was used. A small increase in 
female-to-male ratios also occurred when pollen was fresh (six hours or less). 
The age of the stigmas appeared not to affect the sex ratio. 
18.3 Producing Female Seeds
If it were possible to know which seeds are female and which are male, marijuana 
growing would be even simpler than it is. There is not practical way to discern 
the gender of a seed - but there is a simpler procedure for producing seeds that 
will all grow into female plants. 
To produce female seeds, the plants are fertilised with pollen with male flowers 
that appear on a basically female plant. Such flowers appear on intersexes, 
reversed females, and hermaphrodites (see section 17). Female plants have an XX 
complement of sex chromosomes; therefore, the pollen from the male flowers that 
form on female plants can only carry an X chromosome. All seeds produced from 
flowers fertilised with this "female" pollen will thus have an XX pair of sex 
chromosomes, which is the female genotype. 
Although the male Cannabis plant can produce female flowers, it cannot produce 
seed; so there is no chance of mistakenly producing seed on a male plant. It is 
possible to use pollen from an intersexual plant that is basically male (XY); 
the resulting crop of seeds will have the normal 1:1 ratio of males to females. 
For this reason, choose a plant that is distinctly female as a pollen source. A 
female plant with a few random male-flower clusters, or a female plant that has 
reversed sex are both good pollen sources. The seed bearer can be any female, 
female intersex, or reversed-female plant. 
In most crops, careful inspection of all the females usually reveals a few male 
flowers. And often, when females are left flowering for an extended period of 
time, some male flowers will develop. If no male flowers form, you can help to 
induce male flowers on female plants by severe pruning. One such procedure is to 
take the bulk of the harvest, but to leave behind some green leaves to maintain 
growth (as described in the section on "Double Harvests" in section 20). Most of 
the plants will continue to form female flowers, but male flowers are also 
likely to form. At times, the plants may not grow particularly well, and may in 
fact form distorted and twisted leaves, but they will produce viable seeds as 
long as some stigmas were white when pollinated. (Remember, it only takes a few 
fertile buds to produce hundreds of seeds.) Pollinate the female flowers by hand 
as soon as pollen becomes available. 
{Figure 82.  A solitary male flower on a female plant provides "female"
pollen.  (Also see Figure 84 for a female reversing sex.)}
{Figure 83.  Growth may not be vigorous, but seeds will form if stigmas are
white when pollinated.}
Under artificial lights, turn the light cycle down to eight hours after cutting 
the plants back. The short cycle helps to induce male flowers on female plants. 
Male-free seed can also be produced by pollen from a natural hermaphrodites. The 
progeny, however, may inherit the hermaphroditic trait, resulting in a crop with 
some hermaphrodites as well as females. This could be a problem if you want to 
grow sinsemilla the next crop. 
18.4 Breeding
Breeding Cannabis is done simply by selecting certain plants to be the 
pollinators and the seeds bearers. Characteristics such as fast growth, early 
maturation, and high potency might be the reasons for choosing one plant over 
another. Selection can be by means of the male plants, the females, or both. A 
simple procedure would be to harvest all male plants, sample each for potency, 
and use the most potent plant for the pollen source. At harvest, compare the 
seeded females for potency, and use seeds from the most potent plant for the 
pollen source. At harvest, compare the seeded females for potency, and use seeds 
from the most potent plant for the following generation. 
There are two basic approaches to breeding. One is inbreeding, and the other is 
outbreeding. Inbreeding involves starting with a single variety and crossing 
individuals to produce seeds. In this way, certain desirable characteristics 
that the parents have in common will probably be perpetuated by the offspring. 
Certain variants with unusual characteristics, such as three leaves to a node 
instead of the usual two leaves, can be inbred continuously until all progeny 
carry the trait. One problem with inbreeding is that other desirable 
characteristics may be lost as the new population becomes more homogeneous. 
Inbreeding plants indoors seems to lead in a loss in potency by the fourth 
generation. (Preceding generations were considered comparable to the original 
imported grass.) 
Outbreeding is crossing two different varieties. Offspring from parents of two 
different varieties are called hybrids. Cannabis hybrids exhibit a common 
phenomenon on plants called "hybrid vigour." For reasons not wholly understood, 
hybrids are often healthier, larger, and more vigorous than either of their 
parents. {Figure 84. Upper left: An old female reversing to male flowering. 
Lower left: Three leaves to a node (trifoliate). Upper right: A plant with three 
leaves to a node alternating with one leaf on next node. Lower right: 
Three-leafed plants sometimes split into two growing shoots.} 
A reference to cannabinoid content of hybrids from crosses between chemotypes 
was made in a 1972 study by the Canadian Department of Agriculture: "The ratio 
of THC to CBD in hybrids was approximately intermediate between the parents ... 
there was also occasionally a small but significant deviation toward one of the 
parents - not necessarily the one with the higher or lower ratio of THC to CBD." 
51 This means that a cross between a midwestern weedy hemp (type III) and a fine 
Mexican marijuana (type I) would yield offspring with intermediate amounts of 
THC and CBD, and which hence would be considered type II plants. 
Homegrowers have mentioned that inbreeding plants often led to a decrease in 
potency after several generation. Outbreeding maintained potency, and sometimes 
(some growers claimed) led to increases in potency. 
One area in which breeding can be useful for homegrowers is the breeding of 
early-maturing plants for northern farmer. Farmers in the north should always 
plant several varieties of marijuana. Mexican varieties generally are the 
fastest to mature. Individual plants that mature early and are also 
satisfactorily potent are used for the seed source in next year's crop. This 
crop should also mature early. Some growers cross plants from homegrown seed 
with plants from imported seed each year. This assures a maintenance of 
high-potency stock. 
Potency Changes Over Generations
It is well-established that plants of the P1 generation (parentals, or the first 
homegrown plants from imported seed) maintain their chemical characteristics. 
(For example, type I plants yield type I progeny whose cannabinoids are about 
equal both quantitatively and qualitatively to those in their native grown 
parents.) This fact is shown by Table 25. 
In the study 66 from which Table 25 has been adapted, individual plants within 
varieties differed by more than four times in CBD content and by more than three 
times in THC content. The researchers also noted that illicit marijuana samples 
contained proportionately less leaf material and proportionately more stem and 
seed material than samples grown in Mississippi. (Mississippi samples may be 
more dilute.) New Hampshire and Panama samples were nearly equal in terms of the 
sum of THC plus CBN. 
One of the questions that persists in marijuana lore is what effect if any a 
change in latitude has on the plant chemotype over a period of generations. 
Non-drug types of Cannabis usually originate above 30 degrees latitude in 
temperate areas. Drug types of Cannabis usually originate in tropical or 
semitropical areas below the 30-degree parallel. Whether this is due entirely to 
cultural practices is questionable. More likely, the environment (natural 
selection) is the prime force, and cultural practices reinforce rather than 
determine chemotype. 
Cannabis is notorious for its adaptability. Historically, there are many 
statements that the drug type of Cannabis will revert to the "fibre" type when 
planted in temperate areas, whereas the fibre type will revert to the drug type 
after several generations in a tropical area. That a change in chemotype is 
actually caused by transfer between tropical and temperate areas has not been 
verified scientifically. (Such studies are ongoing in Europe.) If such changes 
occur, it is also not known whether the change is quantitave (the plant produces 
less total cannabinoids) or whether it is qualitative (succeeding generations, 
for example, change from being high in THC and low in CBD to being high in CBD 
and low in THC). 
We believe that qualitative changes can occur within a few generations, but can 
only guess what environmental factor(s) might be responsible for such a change. 
Probably the change has more to do with adaption of general growth and 
developmental characteristics than with particular advantages that production of 
either CBD or THC may bestow upon the plants. 
The reason we suspect a change in chemotype is that these changes occur rapidly 
in evolutionary terms, in a matter of several generations. This rapidity implies 
that some very strong selective pressure are acting on the plant populations. 
Also, changes in the chemotype seem to occur globally, which implies that the 
selective pressures responsible are globally uniform rather than local 
phenomena. Such globally uniform pressures might be light intensity, daylength, 
ambient temperatures, and the length of the growing season. For example, in 
populations adapting to temperate areas, those plants that are able to grow well 
under relatively lower light intensity and cooler temperatures, and which are 
able to complete development in a relatively short growing season, would be 
favoured over siblings with more tropical characteristics. 
Adaption acts on populations by means of whole organisms which are reacting to a 
total environment. Shifts in the chemotype of the population are probably linked 
genetically to the strong selective pressures exerted on the populations by the 
need to adapt general growth and maturation to either northern (temperate) or 
southern (tropical) conditions. {From the northern hemisphere.} 
18.5 Cuttings
Marijuana growing often transcends the usual relationship between plant and 
growers. You may find yourself particularly attached to one of your plants. 
Cuttings offer you a way to continue the relationship long beyond the normal 
lifespan of one plant. 
To take a cutting, use scissors or a knife to clip an active shoot about four to 
sic inches below the tip. Cannabis does not root easily compared to other 
soft-stemmed plants. Cuttings can be rooted directly in vermiculite, Jiffy-MIX, 
a light soil, or in a glass of water. The cutting is ready to plant when roots 
are about an inch long, in about three to four weeks. A transplant compound such 
as Rootone can be used to encourage root growth and precent fungi from forming. 
Keep the mixture consistently moist but not too saturated. Roots need oxygen as 
well as water in order to grow. Change the water daily if the cutting are in a 
glass of water. Cuttings root best in moderate light, not in intense light 
(HID's) or direct sunlight. The best light is fluorescent set on constant light 
(24 hour photoperiod). 
{Picture.  Comparing rooting mediums.  Left to right: One, roots both in
and removed from rockwool cube; two, perlite; three and four, perlite
vermiculture mixture; five, vermiculite; not shown: cuttings died in
peat-pellets.  Best rooting was in perlite-vermiculite mixture.  Pure
vermiculite also worked well.}
Cuttings taken from the same plant are genetically identical and are clones. 
Clones eliminate genetic differences between individuals, and hence are 
particularly useful in scientific experiments. By using clones, one can 
attribute variations between individuals specifically to outside factors. This 
would be particularly useful when testing, for example, the affect of 
fertilisers on potency. In the 1980's, scientists finally began to use this 
useful tool in Cannabis experiments. 
18.6 Grafting
One of the most persistent myths in marijuana lore concerns grafting Cannabis to 
its closest relative. Humulus, the hops plant of beer-making fame. The myth is 
that a hops scion (shoot or top portion of the stem) grafted to a marijuana 
stock (lower stem and root) will contain the active ingredients of marijuana. 
The beauty of such a graft is that it would be difficult to identify as 
marijuana and, possible, the plant would not be covered under marijuana 
statutes. Unfortunately, the myth is false. It is possible to successfully graft 
Cannabis with Humulus, but the hops portion will not contain any cannabinoids. 
In 1975, the research team of Crombie and Crombie grafted hops scions on 
Cannabis stocks from both hemp and marijuana (Thailand) plants 205. Cannabis 
scions were also grafted to hops stocks. In both cases, the Cannabis portion of 
the graft continued to produce its characteristic amounts of cannabinoids when 
compared to ungrafted controls, but the hops portions of the grafts contained no 
cannabinoids. This experiment was well-designed and carried out. Sophisticated 
methods were used for detecting THC, THCV, CBD, CBC, CBN, and CBG. Yet none of 
these were detected in the hops portions. 
The grafting myth grew out of work by H.E. Warmke, which was carried out for the 
government during the early 1940's in an attempt to develop hemp strains that 
would not contain the "undesirable" drug 58. The testing procedure for the 
active ingredients was crude. Small animals, such as the water flea Daphnia, 
were immersed in water with various concentration of acetone extracts from hemp. 
The strength of the drug was estimated by the number of animals killed in a 
given period of time. As stated by Warmke, "The Daphnia assay is not specific 
for the marijuana drug ... once measures any and all toxic substances in hemp 
(or hop) leaves that are extracted with acetone, whether or not these have 
specific marijuana activity." Clearly it was other compounds, not cannabinoids, 
that were detected in these grafting experiments. 
Unfortunately, this myth has caused some growers to waste a lot of time and 
effort in raising a worthless stash of hops leaves. It has also leg growers to 
some false conclusions about the plant. For instance, if the hops scion contains 
cannabinoids, the reasonable assumption is that the cannabinoids are being 
produced in the Cannabis part and translocated to the hops scion, or that the 
Cannabis root or stem is responsible for producing the cannabinoids precursors. 
From this assumption, growers also get the idea that the resin is flowing in the 
plant. The myth has bolstered the ideas that cutting, splitting, or bending the 
stem will send the resin up the plant or prevent the resin from going down the 
plant. As explained in our discussion of resin glands in section 2, these ideas 
are erroneous. Only a small percentage of the cannabinoids are present in the 
internal tissues (laticiferous cells) of the plant. Almost all the cannabinoids 
are contained and manufactured in the resin glands, which cover the outer 
surfaces of the above-ground plant parts. Cannabinoids remain in the resin 
glands and are not translocated to other plant parts. 
We have heard several claims that leaves from hops grafted on marijuana were 
psychoactive. Only one such case claimed to be first hand, and we never did see 
or smoke the material. We doubt these claims. Hops plants do have resin glands 
similar to those on marijuana, and many of the substances that make up the resin 
are common to both plants. But of several species and many varieties of hops 
tested with modern techniques for detecting cannabinoids, no cannabinoids have 
ever been detected 212. 
The commercially valuable component of hops is lupulin, a mildly psychoactive 
substance used to make beer. To our knowledge, no other known psychoactive 
substances has been isolated from hops. But since these grafting claims persist, 
perhaps pot-heads should take a closer look at the hops plant. 
Most growers who have tried grafting Cannabis and Humulus are unsuccessful. 
Compared to many plants, Cannabis does not take grafts easily. Most of the 
standard grafting techniques you've probably seen for grafting Cannabis simply 
don't work. For example, at the University of Mississippi, researchers failed to 
get one successful graft from the sixty that were attempted between Cannabis and 
Humulus. A method that works about 40 percent of the time is as follows. 
(Adapted from 205) 
Start the hops plants one to two weeks before the marijuana plants. Plant the 
seeds within six inches of each other or start them in separate six-inch pots. 
The plants are ready to graft when the seedling are strong (about five and four 
weeks respectively) but their stem has not lost their soft texture. Make a 
diagonal incision about halfway through each stem at approximate the same levels 
(hops is a vine). Insert the cut portions into each other. Seal the graft with 
cellulose tape, wound string, or other standard grafting materials. In about two 
weeks, the graft will have taken. Then cut away the unwanted Cannabis top and 
the hops bottom to complete the graft. Good luck, but don't expect to get high 
from the hops leaves. {Smoking any plant's leaves will give a short, slight 
buzz.} 
18.7 Polyploids
H.R. Warmke also experimented with breeding programs during the war years. 
Polyploid Cannabis plants were produced by treatment with the alkaloid 
colchicine. Colchicine interferes with normal mitosis, the process in which 
cells are replicated. During replication, the normal doubling of chromosomes 
occurs, but colchicine prevents normal separation of the chromosomes into two 
cells. The cell then is left twice (or more then) the normal chromosome count. 
Warmke's experiments concluded that polyploids contained higher concentrations 
of the "active ingredient." However, the procedure for measuring that ingredient 
was much the same is described for grafting, with probably similar shortcomings. 

Polyploid Cannabis has been found to be larger, with larger leaves and flowers. 
Recent experience has shown that polyploids are not necessarily higher in 
potency. Usually they are about equal to diploid siblings. 
Colchicine is a highly poisonous substance. The simplest and safest way to 
induce polyploids is to soak seeds in a solution of colchicine derived from 
bulbs of winter or autumn crocus (Colchicum). Mash the bulbs and add an equal 
part of water. Strain through filter paper (or paper towels). Soak seeds in the 
solution and plant when they start to germinate. Cultivate as usual. 
Only some of the seeds will become polyploid. Polyploid sprouts generally have 
thicker stems, and the leaves are often unusually shaped, with uneven-sized 
blades. Leaves also may contain more than the usual number of blades. As the 
plant grows, leaves should return to normal form, but continue to be larger and 
with more blades. 
If no polyploids sprout, use less water in preparing the solution. 
Colchicine is also a prescribed drug for treatment of gout and is taken in pill 
form. These usually contain .6 mg per tablet. Use 10 tablets per ounce of water, 
and soak the seeds as described above. 
Colchicine is also sold by mail-order firms which advertise in magazines such as 
Head or High Times. 
Because colchicine is a poison, it should be handled carefully. It is not known 
if plants from seeds treated with colchicine will contain a harmful amount of 
colchicine when plants are grown. Harm is unlikely, because the uptake by the 
seed is so small, and because the colchicine would be further diluted during 
growth, as well as diminished by smoking. But we cannot guarantee that you can 
safely smoke colchicine-treated plants. 



Chapter 19
EFFECTS OF THE ENVIRONMENT ON POTENCY
This chapter deals only with the influence of the environment on the potency of 
your crop. Differences or changes in potency can also result from inherent 
differences between plants, such as in their variety or growth stage, from 
chemical degradation of the harvested marijuana, and from genetic processes that 
take place over several generations of plantings ((For discussion of these other 
causes of differences in potency, see the following sections: "Cannabis 
Chemotypes" in section 2; "Inherent Variations" in section 3' "Breeding" in 
section 18; "Potency and Decomposition" in section 20; and "Storage" in section 
21.)) 
We have emphasised the heredity is the most important factor that determines 
potency. Potent marijuana grows from seeds of potent marijuana. A healthy, 
mature plant bears an abundance of flowers, guaranteeing you a potent harvest. 
Some researchers have investigated the impact of the environment on relative 
potency, since this question is of interest to officials concerned with 
marijuana control as well as to marijuana growers. Their primary goal has been 
to discover the gross effects of different environments rather than to single 
out the effects of any particular factor. A consensus is that the impact of 
environment on potency is small relative to that of the plant's heredity. 
Nevertheless, where scientists have commented on this question, the common 
denominator for higher potency has been stress. 
19.2 Stress
Stress in anything that detracts from the plant's health or vigour. 
Environmental factors such as competition from other plants, low water 
availability, and poor soil conditions are examples of stress factors. 
In many marijuana-growing cultures, farmers have practices that are 
stress-related; splitting the base, severe pruning, bending or contorting the 
stem, and water deprivation are common examples. Of course, the fact that 
marijuana-growing cultures have such practices does not mean that these 
practices actually increase potency, or that this is, or ever was, their intent. 
This original meaning may well have been forgotten centuries ago. For instance, 
cultivation of sinsemilla has been practiced for centuries, not for potency, but 
because the seedless product is easier to process or smoke. 
There does seem to be some underlying relationship between stress and higher 
potency. Stress factors may slow growth in general, but at the same time, may 
not slow the synthesis of cannabinoids. Potency may be affected in much the same 
way by growth factors that are not considered stressful. As described 
previously, marijuana plants grow more compactly and have smaller leaves under 
conditions of relatively warm temperatures, or strong sunlight, or a dry 
atmosphere; they grow taller and have larger leaves when grown under cool 
temperatures, moderate light, or a humid atmosphere. Higher relative potency 
seems to correlate with conditions which favour compact development of the plant 
and its parts. 
The rate of cannabinoids synthesis relative to photosynthesis may be affected in 
ways not apparent. Sunlight, for instance, is a growth factor. In almost all 
cases, the more sunlight the plants receive, the faster and larger they will 
grow. Yet plants grown with intense sunlight seem to maximise potency. Intense 
sunlight can raise plants' internal temperatures to levels that interfere with 
the photosynthesis cycle. Absorption of light energy and conversion to 
biochemical energy continues unimpeded, but the synthesis of sugars is impeded. 
(Under a midday sun, this phenomenon has been observed in other field crops. 
(206)) In marijuana, cannabinoids synthesis may continue unaffected at these 
higher temperatures. This might account, in part, for the slightly higher 
potency of plants grown in tropical zones. 
The subject of potency is mired in confusion and mystery, largely because of 
fertiliser and soil ads, marijuana-growing books, and individuals who promise 
ways of increasing potency or growing super grass. There are no magic formulas 
or secrets to divulge that will make or break the potency of your crop. We have 
tried to play down this type of thinking throughout this book. Choice of seed, 
and a harvest of well-developed buds, far outweigh any other factors in 
determining potency. 
We know of no one who has demonstrated that manipulation of any particular 
environmental factor leads to higher potency. This lack of demonstration 
probably exists for two reasons: (1) environmental effects on potency are 
relatively small compared to the effects of inheritable traits, and hence are 
not easy to discern; and (2) "increased potency" is difficult to prove ((Most 
scientific experiments are observations, and test effects or compare results 
rather than try to prove something.)) The variations in potency within any 
variety, and within each plant, require stringent methods of sampling for 
comparative tests. And since potency also changes with time, meaningful 
comparisons can be difficult to make. Scientific papers reflect this difficulty. 

An experiment on potency must account for inherent variations in potency before 
environmental effects can be analysed. Samples would need to be equivalent in 
terms of variety, growth stage and development, sex, plant part, and the 
position of the part on the plant. A simple way to do this would be to harvest 
females when each reached full bloom and then compare the uppermost buds from 
each plant. 
Most of the research on potency done to date either has not reported sampling 
techniques or did not account for certain inherent variations. In the extreme 
case, all vegetative matter from one plant was mixed together, and the THC 
concentration in a sample of this matter was compared with that in a similar 
sample of mixed marijuana from another plant. Such practices can give misleading 
results. Consider the fact that an unhealthy plant will have dropped many of its 
lower, less-potent leaves. A healthy plant has more leaf overall and retains 
more of its lower leaves. There is a good chance that the unhealthy plant will 
test higher in average THC content, because proportionately shoots, which are 
relatively more potent. Such a sampling error could create the impression that 
stress is positively correlated with potency. 
Marijuana scientists have recognised the need for testing equivalent samples and 
for setting standards for testing. In 1974, the English scientist John Fairburn 
(68) published a number of well-controlled experiments concerning potency and 
light. This is a hopeful sign that more meaningful experiments will be 
forthcoming. 
We have said that the common denominator for increasing potency is stress. Let's 
put that in perspective. 
You cannot go wrong if you grow the largest and healthiest plants possible. Our 
experience has been that the most potent plants are more often the healthiest 
and most vigorous in the garden. 
Factors that limit growth rate are probably related to potency, and if growth 
rate is relatively slower, cannabinoids concentrations may be higher. Plants 
whose average yield is six ounces may be slightly more potent than plants whose 
average yield is eight ounces. Factors related to potency affect growth rate 
rather than ruin the plant's health. When a plant is so traumatised that it is 
barely surviving, potency as well as growth rate declines. 
Obviously, if the growth rate is slower, the harvest will be smaller. Any 
difference in potency due to stress is quite small, but the difference in yield 
can make the difference between harvesting an ounce and harvesting several 
pounds (ie., don't get carried away with the practice of stressing the plants). 
If you wish to stress the plant, wait until it is firmly established and growing 
well. 
Outdoors, don't stress the plant until at least the middle of its life. You want 
the plant to be large enough to bear a good harvest of buds. Water deprivation 
is a good method of limiting growth outdoors. However, wilted plants must be 
watered, or they will die. 
Competition from other weeds has been correlated with higher potency in two 
recent studies (71,74). You might prefer not to weed your patch after the 
seedling stage. (Initially, weeding is necessary because indigenous weeds 
generally outgrow marijuana seedlings.) 
Another safe way of applying stress is to remove all large leaves from the plant 
once it has begun to flower. 
Indoors, the plants are already in a delicate state. We advise indoor growers to 
grow the largest and healthiest plants possible for best results. 
19.3 Nutrients
Most growers show a keen interest in fertilising, since it is one factor over 
which they have some control. Most growers also feel that nutrients, which play 
such an important part in plant growth, probably have a relationship to the 
potency, and this is a reasonable assumption. In marijuana lore, potency is 
sometimes attributed to particular soil types (for instance, red dirt, which is 
iron-rich) or to presence or lack or certain nutrients (for examples, nitrogen 
or potassium deficiency). 
The relationship of potency to soil conditions, in particular the nutrient 
content, has been looked at recently by several research groups. In two such 
studies, (71,74) the cannabinoid content of naturalised weedy hemp stands in the 
Midwest was examined. Variations in potency were then correlated to soil 
properties, such as N, P, and K content. The two papers came to similar 
conclusions. First, stands growing in areas where they were under stress tended 
to produce less biomass (yield) but were more potent overall. Second, when 
nutrients or other growth factors, such as height and weight of plants or root 
size, were correlated with potency, potency was almost always correlated 
positively with positive growth factors. That is, higher potency occurred when 
the plants were growing with adequate or high amounts of nutrients present, not 
when nutrients were inadequate. 
What appears to be a contradiction (stress leads to higher potency, or good 
growing condition lead to higher potency) may be explainable in terms of what 
these experiments actually measured. 
A basic assumption in these studies was that all the plants were relatively 
homogeneous genetically, since they may have originated from a single stock of 
hemp grown during World War II. Assuming this is true, then variations between 
stands would be due to differences in local environmental factors. However, 
since environmental condition differed locally for separate stands, one cannot 
tell whether variations in potency between stands are due to present 
environmental factors (phenotypic responses) or reflect thirty years of adaption 
by each stand to its local environment (genotypic shifts). 
It may be that positive growth factors are associated with higher potency in 
phenotypes (plants now growing), whereas stress leads to higher potency in 
succeeding generations, because of selective pressure. It is interesting that 
both papers reported strong positive correlations between higher potency and 
competition from other weeds, since competition between plants does exert strong 
selective pressures. 
The following list of possible effects of nutrients on potency has been adapted 
from these four studies. (63,71,74,231) 
Nitrogen
Nitrogen was positively correlated with higher potency. Once controversy in 
marijuana lore is whether a nitrogen deficiency during flowering increases 
potency. We have grown plants with N deficiencies, and they seemed no more 
potent than those grown with high amounts of nitrogen available. However, the 
N-deficient plants did produce a much smaller harvest. 
Phosphorus
P has been correlated positively with higher potency in all studies that have 
examined this factor. Phosphorus is necessary for good flower development and 
seed production. Give the plants a steady supply of phosphorus throughout growth 
and in particular during flowering. 
Potassium
K has been correlated both positively and negatively with potency. More often, 
it has been found to be negatively correlated. As discussed previously, plants 
that show some potassium deficiencies may grow well; so you may choose not to 
treat minor symptoms of K deficiency often grows vigorously with little harm 
other than the spotting and the loss of some lower leaves. It should not be 
necessary to fertilise with potassium during flowering unless deficiency 
symptoms are severe and the plant has ceased growing. 
Calcium
Abundant Ca levels have been consistently correlated with higher potency. 
Magnesium
Mg has been negatively correlated with potency. However, this may have been dur 
to the interaction of Ca and Mg, and may reflect Ca's strong positive 
correlation to potency, rather than the negative effects of Mg per se. Plants 
that show Mg deficiencies must be fertilised, or they will quickly lose most of 
their leaves and barely remain alive. 



Chapter 20
HARVESTING
Figure 30 is a hypothetical plot of the increase in potency of a male plant and 
a female during the course of their growth. (Potency is measured by the 
percentage by weight of THC in a dried sample of the uppermost leaves or growing 
shoots until flowers appear.) It shoes that generally potency increases as the 
plant develops. Cues such as phyllotaxy changes and rate of growth are helpful 
indicator to changes in development and the chronological age of the plant has 
little significance. 
The development of the cannabinoids, resin glands, and, in practical terms, the 
potency in the living plant is not clearly understood. We believe that,, for the 
most part, potency does not increase steadily throughout the entire plant. 
Rather, each plant part reaches a point of maximum potency as it individually 
develops. A leaf that is formed when the plant is four weeks old does not 
increase in potency during the rest of the season. To say that potency is 
increasing means that the leaves that are now forming are more potent than those 
previously formed. 
We also believe that cannabinoid formation is very fast as each plant part 
forms. Once matured (for example, when a leaf is fully expanded), cannabinoids 
are decomposing. This is one reason why the potency can decrease as well as 
increase during growth, especially late in the season, after the flowers have 
formed. The practical aspects of these points are detailed in the following 
sections. 
20.2 Harvesting During Growth: Leaves and Growing Shoots
Leaves
We have emphasised that you should harvest grass during the course of the 
season. One reason is to assure yourself a return for your efforts. It is a sad 
commentary on our times that the greatest danger in growing marijuana outdoors 
is that the plants may be ripped off. On a more positive note, vegetative shoots 
and leaves can be surprisingly potent and should be sampled. 
The potency of each new set of leaves is higher than the last pair until a 
plateau is reached, usually during the middle of vegetative growth. Thereafter 
potency of new leaves stays about the same as in those preceding. Often there is 
a noticeable decline in potency just prior to flowering. Leaves that form during 
flowering are usually more potent than those formed during the vegetative 
plateau. Leaves that form after the bloom are less potent. 
Of course, not all varieties or individual plants will follow this rhythm. 
Faster-developing plants may reach the plateau sooner, and slower plants later. 
Potency of plants that have a longer life cycle may stay at the vegetative 
plateau for several months. Some plants do not seem to experience any drop in 
potency before flowering. Potency of these plants continues to increase 
gradually after the initial quick increase during early vegetative growth. 
Whenever you harvest green leaves during growth, you should always take the 
uppermost leaves, since these are the most potent. Also, the smaller leaves that 
form on the branches are more potent than the large leaves on the main stem. 
These large stem leaves (fan, shade, or sun leaves) are often the first leaves 
that growers pick. But these are the least potent of all leaves, and the may not 
get you high at all. As long as these leaves are healthy and green, let them 
stay on the plant for the plant's growth. Many growers simply use these leaves 
for mulch or compost as they die. 
Don't think that you should harvest each leaf as soon as it appears; this 
procedure would seriously affect normal growth and result in a small harvest of 
buds. The potency of individual leaves does not increase during the course of 
the season, but the decrease in potency is not great. Some of the loss in 
potency may even be made up for by the loss in tissue weight that a leaf 
experiences as it dies. Many growers prefer to harvest leaves during growth only 
after they lose colour, preferring the taste of the smoke to that of green 
leaves. 
Leaves should always be harvested if they die; with indoor gardens, remove any 
leaves that show signs of insects or other pests. 
Do keep yourself supplied with grass (that is the reason you are growing the 
plant); just don't overdo it. The main harvest is made up of buds, and you want 
a large, healthy plant that can support vigorous flowering. The larger and 
healthier a plant is, the more leaf you can harvest without seriously affecting 
the plant. 
Growing Shoots
You may prefer not to clip the growing shoot of the main stem. This forms the 
largest and most potent cola by harvest time. Plants grown close together 
usually are not clipped, so that the plants may grow as tall as possible. Where 
there is much space between plants, the main shoot is clipped to encourage the 
plant to develop its branches, which fill the available space. 
The potency of growing shoots follows the rhythm described for new leaves. 
However, growing shoots can be the most potent parts of the harvest when picked 
at the right time. Shoots sometimes reach a very high peak of potency during the 
middle of vegetative growth. Outdoor gardens should be samples from mid-June 
through July, since this is the period in which shoots usually reach their peak. 

Potency also fluctuates according to local weather conditions. Try to harvest 
after a period of clear, sunny weather. Potency may declining for several days 
after a period of cloudy weather or heavy rainfall. After a heavy rain, harvest 
the shoots a week or two later, since the shoots often peak in potency during a 
burst of fast growth. 
Growing shoots can be harvested from each plant at least twice during growth. 
The first clipping may not give you much worthwhile grass, but it is done when 
the plants are young (roughly six weeks old) to force the plant to develop 
several growing shoots which are harvest about six to eight weeks later. The 
main shoot is clipped, leaving about four or five nodes below the cut. Two 
shoots should start to grow from each node, the strongest at the top of the 
plant and the weakest at the bottom. (This difference is more pronounced under 
artificial light, since the light is strongest on the top of the plants.) Each 
plant should produce at least six strong growing shoots after this first 
clipping. The yield from growing shoots can be considerable (especially during 
the summer marijuana drought) and will probably keep you supplied until the main 
harvest. 
A third harvest of shoot can be made later if the plants have a long growing 
season or are indoors. You don't want to clip shoots from the plants just prior 
to or during flowering, since doing so cuts down on the harvest of buds. Each 
plant should have at least twelve growing shoots after being clipped twice 
previously. You might harvest only a few shoots from each plant if the time for 
flowering is near. 
20.3 Male Plants
Male plants usually do not have the dramatic increase in potency during 
flowering that the females do. Male flowers take about two weeks to mature, from 
the time they are first visible as tiny knob-like buds. New flowers continue to 
appear for several weeks. 
When male flowers open and are about to release pollen, they reach their maximum 
potency. Since all flowers do not mature at the same time, for maximum potency 
the plants should be harvested after the first few flowers have opened. 
Male flowers actually make up little of the total weight of the harvest, and few 
new leaves form once flowering begins. There is no significant loss in either 
potency or yield if the male is harvested before its flowers open. Once male 
flowers appear, there is little change in their potency. Also, once the flowers 
do open and release pollen, they shortly fall from the plant and are lost to the 
harvest. 
Males should therefore be harvested before any flowers open unless you want the 
females to produce seeds. In a small garden, male flower clusters can be 
individually harvested as they mature. Most growers treat male flowers more as a 
novelty. Potency of male flowers is quite variable, and seldom are they as good 
as the female flowers. To remove male plants, cut them near the base of the 
stem. Don't rip them up by the roots if they are near females that will be left 
to grow. 
Male plants normally begin to lose their vigour after the initial bloom. When 
the weather is mild, or the plants are indoors, they can be encouraged to bloom 
a second and sometimes a third time before they finally die. 
20.4 Harvesting Female Buds
The decision of when to harvest females can be simplified by understanding that 
you want to pick the buds after they have developed fully, but before 
degradation processes begin to lower potency. There are two criteria you can use 
to tell when the plants have reached full bloom. The first is recognising the 
rhythm, with which the plants are blooming. A second is the condition of the 
flowers as judged by the health of the stigmas and the colour of the resin. 
Sinsemilla
Since sinsemilla flowers are not pollinated, the flowering period may last for 
many weeks. The most common rhythm for sinsemilla is that plants go through a 
stage of rapid bud formation, and the plants do indeed bloom. This bloom often 
lasts four to five weeks. The bloom ends when the rate at which new flowers form 
noticeably declines. At his time you should be able to sense that the bloom is 
completed. Buds are at their peak potency about one week after flower formation 
slows. This is the time to harvest. True, the plant may continue to grow slowly, 
but the main harvest is ready and should be taken. 
With sinsemilla, some marijuana varieties have an extended bloom that may last 
more than two months. With this rhythm, the rate at which the buds form is drawn 
out, and progresses at a slower but steadier pace. The point at which the bloom 
is essentially over may not be as obvious as in the first case. Here, use the 
condition of the buds to make your decision. Stigmas wither first at the base of 
the buds (older flowers). Those stigmas at the top of the buds (younger) will 
still be white and healthy, although their tips are often brown. Harvest the 
plants when about half the stigmas in the buds have withered. The coating of 
resin glands should still be clear or white, with only a few golden or browned 
gland heads. 
A third type of flowering rhythm is sometimes seen on plants from Thai seed. 
Flower buds bloom and ripen at different times. These plants also have an 
extended flowering stage that can last for over two months. You may choose to 
harvest individual buds, colas, or branches as they ripen. 
Seeds
If your primary interest is seeds, the plant should be harvested after the seeds 
have developed their mature colour. Mature seeds can be seen splitting their 
sheaths or bracts. When enough seeds have ripened, the plants should be 
harvested. If the plants are left in the ground and die, many of the seeds will 
fall from the plant. 
For most growers, potency will be of primary interest, seeds only a secondary. 
With seeded marijuana, flowering is initially rapid until the plant is 
well-pollinated. If pollination occurs early in flowering, the plants often 
bloom for another week or two. Generally, you want the plants to flower for at 
least four weeks before picking, and usually longer, about six to seven weeks. 
With seeded marijuana, the bloom is of shorter duration than with sinsemilla. 
Once growth slows, wait another two to three weeks before harvesting. All the 
seeds may not be matured, particularly at the top of the bud. But potency of the 
buds should be about maximum at this time. 
20.5 Weather
Because of such variables as variety and growing conditions, there can be so 
much variation in the ripening process that no one criterion for judging when 
maximum potency is reached will be reliable for all cases. 
Warm, sunny weather encourages rapid flowering and a long period of receptivity 
by the stigmas. Cool, rainy weather can wither the stigmas and dampen the vigour 
of the bloom. 
If brief frost or long, cool rain has withered the stigmas, use the plants' 
growth as a guideline, because ultimately this is the most important criterion. 
You want the buds to reach a mature size, and to ripen for about another week. 
You do not want the buds to be left on the plant longer than necessary. 
Ideally, harvesting should follow a period of warm, sunny weather. In northern 
and mountainous parts of the country, many tropical varieties will note flower 
until late in the season, when the weather has cooled and night-time frosts are 
threatening. Most mature plant can withstand mild frosts and continue to grow 
well if daytime temperatures are mild. In this case, let the plants mature, 
since formation of the buds is more important than the weather in determining 
potency. Watch the plants carefully, and harvest when the buds reach mature 
size. Marijuana killed by frost may smoke harshly, but potency does not seem 
affected. Well-formed buds should be picked if heavy rains are expected. 
Cannabinoids are not water-soluble, but gland heads will be washed away. 
Barring a catastrophe, such as a long frost, death to Cannabis is usually not 
sudden. The plants will continue to grow, and may infact rejuvenate the next 
year if the stalks are left in the ground. But after the main bloom, the growth 
that follows is usually much less vigorous and sometimes forms abnormally. 
Leaves at this time are simplified, and have one blade. Later leaves are 
smaller, and tend to have entire margins (no serrations). Sometimes they are 
twisted or misshaped, as are the flowers that form along with them. This slow 
growth that follows the initial bloom will contribute little to the weight of 
the harvest. Additionally, this post-bloom growth is much less potent than the 
original bloom. Resin glands on these plant parts are feeble and poorly 
developed. When this abnormal growth forms, the time for harvesting is past. 
{See Figure 83.} 
When a plant seems to persist in growing, and you are not sure bloom is past, 
the best procedure to follow is to try for a double harvest. 
Double Harvests
Most marijuana plants take at least five months to reach maturity. Once the 
plant has reached maturity, it is forming its most potent marijuana, and should 
not be cut down completely. You can often induce the females to flower a second 
(and sometimes a third) time, especially if the plants are indoors or if the 
weather is expected to stay mild for several more weeks. 
To encourage a second bloom, first take the bulk of the harvest: all but the 
smallest buds, and most of the leaf. Some green leaves should be left on the 
plant to maintain the plant's growth. After harvesting, give the plants a 
thorough watering, and water with a soluble, complete fertiliser that provides a 
good supply of both N and P. This will encourage new growth and continued 
flowering. 
Indoors, the best procedure is to treat the plants like a hedge. Cut all the 
plants back to equal heights, about two to three feet tall. Remove most of the 
grass, but again leave a few green leaves on the plant. Don't remove lower 
branches even if they are leafless, since these will sprout again. Lower the 
light system to the tops of the plants, and maintain the daily cycle at about 12 
hours. The second crop of buds will be ready for harvest in four to eight weeks. 
With this system, the plants appear like dense hedges of buds. If the second 
crop of buds forms quickly, you should try for a third crop. Continue to 
fertilise the plants regularly, and watch for signs of magnesium deficiencies, 
which often show up when the plants have been growing for an extended time. 
Double and triple harvests are one of the benefits of indoor growing. Although 
plants are relatively small indoors, the original harvest of buds can be triples 
in the next four months. 
20.6 Potency and Decomposition
We have said that when buds are picked too late, the potency may decline because 
of decomposition of the cannabinoids, especially THC. 
In section 21, Tables 26-29 give measured rates of decomposition of the major 
cannabinoids due to exposure to light and air. Light rapidly decomposes THC into 
unknown products (possibly polymers (122,164)). Light also converts CBD to CBS 
and CBC to CBL. Air (oxygen) slowly converts THC to the less active CBN. 
Conversion to CBN is hastened by higher temperatures. 
Degradative processes do not occur as quickly in the living plant as when the 
cannabinoids are purified or in solution, as is shown by the data in Tables 
27-30 in section 21 {Tables on disk only}. Resin glands seem to function well in 
storing the cannabinoids in dried plant material. However, the rates of 
decomposition in Tables 27 and 28 are for samples exposed to north light and a 
maximum of 80F temperatures. Temperature would be higher, and light stronger, 
under full sunlight. 
Studies with fresh plant material usually show negligible CBN content in fresh 
marijuana from immature plants. When mature buds are tested, their CBN content 
is generally equal to at least five percent of their THC content. When growing 
temperatures are higher, such as in the tropics, CBN content can account for 
more than 20 percent of the original THC. Even if we assume a low figure, such 
as five percent conversion of THC to CBN, there is actually a much greater 
decline in THC content because of the simultaneous degradation of THC by light. 
When the slow rate at which THC oxidises to CBN is considered, five percent 
decomposition in a period of less than two months represents considerable 
exposure of the THC to air, and most of this exposure occurs in the last 
critical weeks when the resin glands begin to degenerate. Plates 8 and 11-13 
show the condition of the resin glands on several different kinds of marijuana. 
Stalked glands that cover the female flower bracts sometimes rupture or secrete 
cannabinoids through pores in the glands head. Secretion is not a continuous 
flow, but more of an emptying of the glands' contents. At this time, gland heads 
may dehisce. Also, because of their abundance and raised positions, resin glands 
on the female bracts are exposed to strong sunlight and possible physical 
damage. These conditions may explain the significant decline in potency of buds 
that are overripe. 
Leaves are also affected by decomposition of the cannabinoids, but not as 
quickly or seriously as the buds, probably because the resin glands on the 
leaves are most numerous on the undersurface, where they are somewhat protected 
from light. These glands rarely rupture or secrete cannabinoids. Often they are 
intact, clear, and apparently unchanged for many weeks on the living plant. 
As the plates show, one can, with the naked eye, see the glands change colour, 
from colourless or white to golden, and then to reddish or brown. THC is 
colourless. If the colour changes of the resin do indicate decomposition of THC, 
then decomposition in the stalked glands that cover the buds can be 
considerable. 
We have smoked buds that seemed to lose about half their potency when left on 
the plant for an addition three weeks. Colour changes are after the fact. If 
many of the glands are beginning to brown, the grass should be harvested. 
20.7 Timing the Harvest
Many growers will disagree with us on when the best time is to harvest the buds 
(female plants). When the plants are left in the ground, and are alive but past 
the main bloom, the resinous qualities of the plant may become more apparent. 
The bracts and tiny leaves may swell in size, and the leaves feel thicker. The 
coating of resin glands will change colour. Leaves often yellow and fall form 
the plant. Much of the green colour in the flowering buds may also be lost. 
Harvests of these buds more closely resembles commercial Colombian grass than 
typical homegrown. The resin content of the dried buds may be higher, and the 
grass will smoke more harshly than if the buds were younger when picked. You may 
prefer these qualities in your grass, and some growers insist this grass is 
stonier. We feel that the grass will give you the highest high when it is picked 
as described previously. Smoking is a personal experience, and you should try 
different approaches and come to your own conclusions. 
The first time you grow marijuana is largely a learning experience. Most growers 
can't wait to start their second crop, because they are certain that they'll 
improve on both the quantity and the quality of their crop, and this is usually 
true. The wise grower will not put all his proverbial eggs in one basket. It is 
a good idea to monitor potency by taking samples every few days when harvest 
time is drawing near, just as such monitoring is for deciding when to harvest 
growing shoots during vegetative growth. 
In any garden, some of the plants will mature sooner than others. Use the 
plant(s) that is earliest to mature to decide at what point in its development 
the plant reaches maximum potency. This finding then serves as a guide for 
harvesting the rest of the plants. 
Try to use buds from approximately the same position on the plant each time you 
sample. Take only enough to make a joint or two. The more you standardise your 
testing (and this includes your smoking evaluation), the more accurate your 
results may be. 
20.8 Final Harvesting
The time of harvest is a time of joy. It is also a time for caution. Unless the 
safety of your garden is assured, you will want to harvest quickly, quietly and 
as efficiently as possible. Ideally, each plant is harvested as it matures, but 
some of you will have to harvest all at once. 
It is best to take cardboard boxes or large, sturdy bags to carry the harvest. 
You want to harvest the plants with as little crushing or damage to the flowers 
as possible. 
Bring a strong knife, heavy shears, or clippers for cutting the stalks. The 
quickest way to harvest is to cut each plant at its base. Once the plants are on 
the ground, cut the stalks into manageable lengths for boxing or bagging. 
Separate large branches as needed for packing. 
The bagged or boxed material should be moved to the curing or drying area as 
soon as possible. If you let the plants sit in the trunk of a car or in plastic 
bags, they will start to ferment and small in less than a day. 



Chapter 21
AFTER THE HARVEST
Once the marijuana plant is harvested, it ceases to produce cannabinoids and 
resins, and the main changes in potency that occur are degradative. However, 
when the material is handled carefully, dried or cured properly, and then stored 
well, little degradation will occur. During drying or curing, the resin content 
may seem to increase, as the plant's tissues shrink away from their resinous 
coating. 
More than 70 percent of the fresh weight of the plant os water. Drying is done 
to evaporate most of this water, so the marijuana will burn evenly and smoke 
smoothly. Additionally, the cannabinoids in fresh plant material are mostly in 
the acid forms, which are not psychoactive. The acid cannabinoids decarboxylate 
(they lose the gas, carbon dioxide) during the drying or curing processes, which 
convert them to their psychoactive neutral forms. Decarboxylation is complete if 
the marijuana is actually smokes. For this reason, no special procedures are 
needed to decarboxylate the marijuana unless it will be eaten. In that case, the 
recipe should include a period of dry heating. The heat converts the 
cannabinoids to their psychoactive neutral forms, and also melts the 
sharp-pointed cystolith hairs that cover leaves, stems and petioles. Cystolith 
hairs can cause stomach pains if you eat uncooked marijuana or chew on raw 
marijuana, which we strongly advise you not to do. 
Commercial marijuana us usually composed of just the flower tops (colas), which 
have been stripped, manicured, cured, and dried. Homegrowers often do not cure 
their crop before drying, and if the smoke is smooth, there is no reason not to 
dry it directly. But harsh-smoking marijuana can be cured so that the smoke is 
smoother. Curing has little affect on potency when done properly. 
21.2 Stripping
Stripping, the removal of large leaves, is usually done soon after harvesting. 
Fan leaves are stripped because they are much less potent than the colas that 
they cover, and do not cure as well as the prime material. In commercial growing 
areas, the fan leaves are often stripped in the field and form a green manure. 
But fan leaves are sometimes quite potent, especially if they are recent growth. 
The lower leaves are usually weak, but they can be used in cooking or 
concentrated in an extract. 
The easiest time to strip fan leaves is after they have wilted, because they are 
easier to pull off when they are limp then when they are turgid. Wilting takes 
place in less than an hour if the plants are in a well-ventilated space. Plants 
placed in a plastic bag in a cool area may take a day or more to wilt. 
Some growers leave the fan leaves on until the plants have dried. After the buds 
are removed, they strip the remaining leaves by running their (gloved) hands 
from the base of stems and branches toward their tips. The fan leaves 
disintegrate into shake. 
21.3 Grading and Manicuring
Grading and manicuring are important steps in preparing fine grass. Grading is 
done by separating the plants according to variety, sex, and the particular 
stash uniform, and the quality of the better grades is not diluted. Plant parts 
are usually graded as follows: main top colas, small side colas, immature buds, 
leaves accompanying flowers, and fan and stray leaves. This is important, 
because the differences in potency will be considerable. For instance, the buds 
on a Colombian homegrown will be top quality, but the lower leaves will be more 
like a low-grade commercial Mexican. 
Manicuring is done to remove the extraneous leaf from the colas. First the large 
fan leaves are stripped. The exposed colas are then trimmed with scissors to 
remove the ends of leaves that stick out from the colas. Plants should be 
manicured and (usually) graded before drying, since dried material crumbles into 
shake when handled. Also, leaves dry much more quickly than buds, and different 
plant parts cure at their own rates. 
Male flowers are often treated as a novelty by growers, who make individually 
rolled sticks from them, as follows. Hang the plants upside down; the leaves 
will wilt and hang down, covering the male flower clusters. Then roll each 
cluster within its leaves between the palms of your hands, to compress the 
cluster into a joint-shaped mass. Dry the "stick" in a warm dark place. Rolling 
the grass ruptures many of the glands; so dried sticks should be stored 
carefully until each is used. 
Hashish
When you handle your crop, you may notice a resin build-up on your hands and the 
tools you are using. This resin can be collected by rubbing and scraping it into 
a ball. It makes a quality hash that is several times as concentrated as the 
grass. 
Small quantities of hash can be made by rubbing resinous plant parts across a 
thin, fine mesh screen. The resin is then scraped off the screen and rolled into 
finger shapes. Hash can also be made by thrashing fresh plants over a mesh 
screen inside an enclosed box whose floor is lined with sheet plastic. A box 
about one yard square is a suitable size. On one side of the box a hole is made 
large enough for the colas to be shaken by hand. In this way, the resin glands 
are knocked loose, but are contained by the box and settle on the plastic. 
Plastic or paper should be placed beneath the marijuana during manicuring, 
grading, or drying. Besides fallen grass, a considerable amount of glands and 
fine shake can be caught and compressed to a hash-like mass. 
21.4 Curing
Curing is a process employed to naturally enhance the bouquet, flavour, and 
texture of marijuana. Curing does not lower potency when done correctly, 
although poor curing methods often result in some less of THC. 
Curing is not an essential procedure, and many growers prefer the "natural" 
flavour of uncured grass. Sweet sinsemilla buds usually are not cured. 
Curing is most successful on plants which have "ripened" and are beginning to 
lose chlorophyll. It is less successful on growing tips and other vigorous parts 
which are immature. These parts may only lose some chlorophyll. 
Curing proceeds while the leaf is still alive, for until it dries, many of the 
leaf's life processes continue. Since the leaf's ability to produce sugars is 
thwarted, it breaks down stored starch to simple sugars, which are used for 
food. This gives the grass a sweet or earthy aroma and taste. At the same time, 
many of the complex proteins and pigments, such as chlorophyll, are broken down 
in enzymatic processes. This changes the colour of the leaf from green to 
various shades of yellow, brown, tan, or red, depending primarily on the 
variety, but also on growing environment and cure technique. The destruction of 
chlorophyll eliminates the minty taste that is commonly associated with green 
homegrown. 
There are several methods of curing, most of which were originally designed to 
cure large quantities of tobacco. Some of them can be modified by the home 
grower to use for small marijuana harvests as well as large harvests. The 
methods used to cure marijuana are the air, flue, sweat, sun, and water cures. 
Air Curing
Air curing is a technique developed in the United States for curing pipe and 
cigar tobacco. It was originally done in specially constructed barns made with 
ventilator slats which could be sealed; a small shed or metal building can 
easily be adapted for this use. However, this method of curing works only when 
there is enough material to keep the air saturated with moisture. 
Wires are strung across the barn, and the marijuana plants or plant parts are 
hung from them, using string, wire twists, or the crooks of branches. The plants 
material should be closely spaced, but there should be enough room between 
branches (a few inches) so that air circulates freely. The building is kept 
unventilated until all the material loses some chlorophyll (green colour). This 
loss occurs rapidly during warm sunny weather because heat builds up, which 
hastens the cure. In wet or overcast weather, the temperature in the chamber 
will be cooler, and the process will proceed more slowly. If these conditions 
last for more than a day or two, unwanted mould may grow on the plants. The best 
way to prevent mould from forming is to raise the temperature to 90F by using a 
heater. 
After the leaves have lost their deep green and become pale, the ventilator or 
windows are opened slightly, so that the temperature and humidity are lowered 
and the curing process is slowed. The process then continues until all traces of 
chlorophyll are eliminated. The entire process may take six weeks. Then the 
ventilators are opened, and an exhaust fan installed if necessary, to dry the 
material to the point that it can be smoked but still is moist, that is, bends 
rather than crumbles or powders when rubbed between thumb and forefinger. 
Flue Curing
Flue curing differs from air curing in that the process is speeded up by using 
an external source of heat, and the air circulation is more closely regulated. 
This method can be used with small quantities of material in a small, airtight 
curing box constructed for the purpose. Large quantities can be hung in a room 
or barn as described in Air Curing. 
A simple way to control the temperature when curing or drying small amounts of 
marijuana is to place the material to be cured in a watertight box (or a bottle) 
with ventilation holes on the top. Place the box in a water-filled container, 
such as a pot, fish-tank, or bathtub. The curing box contains air and will 
float. The water surrounding the box is maintained at the correct temperature by 
means of a stove or hotplate, fish-tank or water-bed heater, or any inexpensive 
immersible heater. Temperature of the water is monitored. 
With the marijuana loosely packed, maintain water temperature at 90 degrees. 
After several days, the green tissue turns a pale yellow-green or murky colour, 
indicating yellow or brown pigments. Then increase temperature, to about 100 
degrees, until all traces of green disappear. Raise the temperature once again, 
this time to 115 degrees, until a full, ripe colour develops. Also increase 
ventilation at this time, so that the marijuana dries. Plants dried at high 
temperature tend to be brittle; so lower the temperature before drying is 
completed. This last phase of drying can be done at room temperature, out of the 
water bath. The whole process takes a week or less. 
Marijuana cured by this technique turns a deep brown colour. Immature material 
may retain some chlorophyll and have a slight greenish cast. Taste is rich yet 
mild. 
Sweat Curing
Sweat curing is the technique most widely used in Colombia. Long branches 
containing colas are layered in piles about 18 inches high and a minimum of two 
feet square, more often about ten by fifteen feet. Sweat curing actually 
incorporates the fermenting process. Within a few hours the leaves begin to heat 
up from the microbial action in the same way that a compost pile ferments. Then 
change in colour is very rapid; watch the pile carefully, so that it does not 
overheat and rot the colas. Each day unpack the piles, and remove the colas that 
have turned colour. Within four or five days, all the colas will have turned 
colour. They are then dried. One way to prevent rot while using this method is 
to place cotton sheets, rags, or paper towels between each double layer of 
colas. The towels absorb some of the moisture and slow down the process. 
Sweat curing can be modified for use with as little marijuana as two large 
plants. Pack the marijuana tightly in a heavy paper sack (or several layers of 
paper bags), and place it in the sun. The light is converted to heat and helps 
support the sweat. 
Another variation of the sweat process occurs when fresh undried marijuana is 
bricked. The bricks are placed in piles, and they cure while being transported. 
A simple procedure for a slow sweat cure is to roll fresh marijuana in plastic 
bags. Each week, open the bag for about an hour to evaporate some water. In 
about six weeks, the ammonia smell will dissipate somewhat, and the grass should 
be dried. This cure works well with small quantities of mediocre grass, since it 
concentrates the material. 
Sun Curing
A quick way to cure small quantities of marijuana os to loosely fill a plastic 
bag or glass jar, or place a layer between glass or plastic sheets, and expose 
the material to the sun. Within a few hours the sun begins to bleach it. Turn 
the marijuana every few hours, so that all parts are exposed to the sun. An even 
cure is achieved in one to two days {(see Plate 16)}. Some degradation of THC 
may occur using this method. 
Water Cure
Unlike other curing methods, the water cure is performed after the marijuana is 
dried. Powder and small pieces are most often used, but the cure also works with 
whole colas. The material is piled loosely in a glass or ceramic pot which is 
filled with luke-warm water. (When hot water is used, some of the THC is 
released in oils, which escape and float to the top of the water.) Within a few 
hours many of the non-psychoactive water-soluble substances dissolve. An 
occasional gentle stirring speeds the process. The water is changed and the 
process repeated. Then the grass is dried again for smoking. 
THC is not water-soluble; so it remains on the plant when it is soaked. By 
eliminating water-soluble substances (pigments, proteins, sugars, and some 
resins), which may make up 25 percent of the plant material by weight, this cure 
may increase the concentration of THC by up to a third. 
Marijuana cured by this method has a dark, almost black colour, and looks 
twisted and curled, something like tea leaves. The water cure is frequently used 
to cure dried fan leaves and poor-quality grass. 
21.5 Drying
Living marijuana leaves are 80 percent water; colas are about 70 percent water. 
Marijuana dried for smoking contains only eight to 10 percent water, or about 10 
percent of the original amount. There are several methods used to evaporate 
water; these have little effect on potency, but can affect the taste, bouquet, 
and smoothness of the smoke. Generally, the slower the dry, the smoother the 
taste. Excess drying and drying methods that use heat will evaporate some of the 
volatile oils that give each grass its unique taste and aroma. 
Grasses which are dried as part of the curing process usually have a smooth, 
mild taste, because of the elimination of chlorophyll and various proteins. 
Cured marijuana may also be a little sweeter than when first picked, because the 
curing converts some of the plant's starch to simple sugars. 
Some grasses are tasty and smooth-smoking when they are dried without curing, 
especially fresh homegrown buds which retain their volatile oils and sugar. Many 
homegrowers have acquired a taste for "natural" uncured grass, with its minty 
chlorophyll flavour; such marijuana is dried directly after harvesting. {Figure 
89, Male plants drying on a tree. Cheesecloth holds loose leaf for drying.} 
Slow Drying
Slow drying is probably the method most commonly used to dry marijuana. Because 
of the slowness of the dry, a slight cure takes place, eliminating the bite 
sometimes associated with quickly dried grass. 
There are many variations of the technique, but most commonly whole plants or 
separated colas are suspended upside down from a drawn string or from pegs on a 
wall in a cool dark room, closet, or other enclosed space. A large number of 
plants may take a week or two to dry. The drying time for small numbers of 
plants can be increased (for a slight cure) by placing the plants in large, open 
paper sacks that have ventilation holes cut in their sides. The drying room 
should have no heavy drafts, but mould may form on the plants if the air is 
stagnant. If weather is rainy or the air humid, increase ventilation and watch 
for any mould. Plants should be dried quickly under moderate heat if any mould 
appears. 
Many experienced growers prefer slow drying to curing. There is little chance of 
error with this method, and buds usually smoke smooth and develop a pliable 
consistency. Slow-dried ripe buds retain their delicious, sweet aroma and taste. 

Fast Drying
The fast dry-method produces a harsher smoke than slow drying, but it is often 
the most convenient method to use. The plants are suspended in the same way as 
for slow drying, but the temperature in the drying area is increased to between 
90 and 115 degrees, often by means of electric or gas heater. The drying area is 
kept well-ventilated with a fan. As the plants dry, they are removed from the 
drying area. By this method, plants in a tightly packed room can be dried in 
less than four days, but the exhaust will contain the deliciously pungent odour 
of drying marijuana. 
Indoor growers often hang plants to dry over radiators or stream pipes. Leaves 
are dried by placing them on a tray over a radiator or on top of the light 
fixture. 
Marijuana that is fast-dried retains its original green colour and minty taste. 
Oven Drying
Oven drying is often used by gardeners to sample their crop. Small quantities of 
material can be quickly dried by being placed in a 150 to 200 oven for about 10 
minutes. Larger quantities can be dried in trays that contain a single layer of 
material or in a dehydrator. Oven-dried and dehydrator-dried marijuana usually 
has a harsh taste and bite, and loses much of its bouquet. The method is often 
used to dry marijuana which has been cured and dried but is too moist to smoke, 
or to dry marijuana which is to be used for cooking or extractions. It is an 
adequate method for obtaining dry material for testing and emergencies, but the 
main harvest should not be dried in this way. Oven drying works best with 
leaves. When leaves are dried together with buds or shoots, remove the material 
from the oven periodically, to separate the faster-drying leaf material (before 
it burns) from the slower drying buds. One way to do this is to place all the 
material on a wire screen over a tray. Every few minutes rub the material across 
the screen. Dried material falls unto the tray and is removed from the oven. 
Repeat until all the material has dried. 
Oven curing works well when closely watched. Dried marijuana that is left in the 
oven will lose potency quickly. Any time the marijuana begins to char, most of 
the potency will already have been lost. This should not be a problem unless you 
are careless, or allow the temperature to go above 200 degrees. 
Sun Drying
Some growers dry their crops right in the field. There are many methods of sun 
drying. In Oregon, some growers break the main stem about two feet from the 
ground. The leaves and buds dry gradually, since they are still partly attached 
to the plant. Other growers spread burlap and cover it with plants left to dry. 
Fan leaves are left on the plants to protect the drying buds from the sun. The 
grass is manicured after drying. Growers in Arizona shade drying plants with 
cheesecloth. 
Sun-dried marijuana usually has a taste similar to that of oven-dried. Often the 
sun bleaches it slightly but also destroy some of the delicate bouquet. 
Prolonged exposure to the sun will decrease potency, although there is no 
noticeable loss if drying is done quickly. 
Dry Ice
Many homegrowers have written to us that the dry-ice cure increases the potency 
of marijuana considerably, and we would be remiss not to mention it. 
Dry ice is frozen carbon dioxide. When it melts (sublimates), it turns from a 
solid directly into a gas. This gas absorbs some moisture from the frozen 
marijuana and partially dries it. 
There are many variations of the dry-ice method. Fresh or partially dried 
material is usually used, although some enthusiasts claim that the cure also 
works with dried material. The marijuana is placed in a coffee can or similar 
container with a lid, along with at least an equal volume of dry ice. Puncture 
the lid so that the gas can escape as it evaporates. Place the can in a freezer 
to prolong the evaporation process. When the dry ice is gone, the grass is 
dried, but still moist. 
Some growers claim that simply freezing the grass increases potency. They often 
freeze fan leaves or other less-potent material for a couple of months before 
smoking it. This is said to work only with fresh (wet or dried) grass. 
21.6 Fermentation
When vegetation dries, the individual cells which maintained life processes die. 
But marijuana can still be conditioned by means of fermentation. Fermentation is 
the process in which microbes and plant enzymes break down complex chemicals 
into simpler ones, mainly starch and sugars into alcohol and simple acids. In 
the process chlorophyll is destroyed, giving the material a more ripened 
appearance. If the fermentation is stopped early, the marijuana has a sweeter 
taste because of the sugars which the ferment produced. 
Fermentation occurs when the moisture content of the marijuana is raised above 
15 percent and the temperature is above 60 degrees. The more tightly packed the 
material, that faster the ferment proceeds. The rate of ferment is controlled 
primarily by varying the moisture content, but each batch proceeds at its own 
rate because of differences between plants in nitrogen content. (Nitrogen is 
necessary to maintain fermenting bacteria.) The process is delicate; should the 
ferment proceed too rapidly, the marijuana may be converted to compost. Watch 
the fermentation closely. After the desired colour or flavour (from a dried 
sample) is reached, dry the grass quickly to stop the process. 
During fermentation, flavourings can be added to give the marijuana a spicy 
aroma. Such spices as cinnamon, cloves, ginger, mace, sage, or vanilla are 
placed between the fermenting material. Orange, lemon, or lime peels are also 
used. About half an ounce of spice or four ounces of peel are used for each 
cubic foot of material to be fermented. The spices are wrapped in cloth sachets. 
The citrus peels are strung. They can be placed between the layers of marijuana. 

There are two types of fermentations: self-generating and forced. They are best 
used with leaves or immature plants. 
Self-Generating Fermentation
Self-generating fermentation proceeds rapidly only when there is enough material 
to make a heap at least one cubic yard large. When smaller quantities are used, 
too much of the heat generated by the bacteria is dissipated, so that the 
process is slow and is more properly considered aging. 
Place the material in a large container or in a pile with a tarpaulin placed 
over it, and lightly spray it with a mister if it is dry. Let the pile heat up 
for a few days, and then break it down. If it is repacked, the marijuana will 
develop a dull matte appearance and lose its sugars. IF the process is allowed 
to proceed even further, the marijuana will disintegrate. 
Forced Fermentation
Forced fermentation can be used with small quantities of material. It requires 
an enclose chamber in which heat and humidity can be regulated. 
Pack the marijuana loosely in a kiln or other chamber, and raise the temperature 
to 135 degrees. Maintain humidity at 75 percent. Check the progress of the 
ferment periodically. Within a week the ferment should be completed. During this 
ferment there is a release of ammonia compounds, resulting in some foul odours, 
but upon completion of the ferment and drying, the marijuana should smoke sweet 
and mellow. 
21.7 Storage
THC is degraded by both heat and light. Table 26 shows results of an experiment 
conducted at the University of Mississippi, in which marijuana was stored under 
varying temperature conditions171. These results indicate that marijuana stored 
at room temperature (72) or below, and in darkness for up to two years will lose 
only an insignificant amount of its original potency; whereas marijuana stored 
in darkness at 97 or above will lose almost all its potency within two years. 
In another experiment,164 Fairbairn stored dried marijuana at different 
temperatures in both light and dark conditions. The samples in light were 
exposed to a north-facing windows (no direct sunlight). The results are shown in 
Table 27. 
Fairbairn also performed an experiment to discover the effect of air on THC164. 
Freshly prepared Cannabis resin was stored as a loose powder, a compressed 
powder, and an unbroken lump for one year at 68 degrees F (about room 
temperature). Samples were stored under two conditions: in light and air, and in 
darkness and air. The results are shown in Table 28. 
Fairbairn experimented further with pure cannabinoids and extracts of marijuana 
dissolved in petroleum ether, chloroform, and ethanol (alcohol)165. The results, 
in Tables 29 and 30, show that the THC and CBD in solution are much more 
unstable than when they are left in marijuana, especially if they are held by 
the plant in undamaged glands, where they are protected from exposure to air 
and, to some degree, light. Crude extracts seem more stable than highly refined 
cannabinoids, especially CBD, which is very unstable in refined solutions. 
Extract makers and purchasers should limit the exposure of the solution to light 
and heat as well as to air. Oils and extracts should be kept refrigerated in 
opaque, sealed container. Notice that THC is almost completely degraded in a few 
weeks when it is held in solution and exposed to light. Red oil, hash oil, and 
honey oil must be stored in light-tight containers to preserve potency. 
From the tables, you can see that light is the primary factor that causes 
decomposition of THC. The decomposition products are unknown, but are suspected 
to be polymers or resins. We also do not know whether the rate of decomposition 
would be faster in direct sunlight. 
Air (oxygen) acts much more slowly to convert THC to CBN. Decomposition of THC 
to CBN is not significant unless temperatures are in the nineties or higher. 
However, such high temperatures can occur in grass that is packed before it is 
properly dried. The moisture that is left supports microbial activity, which 
heats the grass internally, as occurs during certain types of curing. Potency of 
cured grass is not lowered significantly when the cure is done properly and when 
the buds are left intact during the process. 
The figures for powdered and compressed grass in Table 28 show that both light 
and air cause rapid decomposition when the resin is exposed through breaking of 
the resin glands. Intact resin glands appear to function well in storing the 
cannabinoids. For this reason, it is important to handle fresh and dried grass 
carefully, in order not to crush the material and thus break the glands, 
especially in the buds, which have a cover of raised resin glands. Most 
well-prepared marijuana will have intact, well-preserved buds. 
The best place to store marijuana is in a dark container in a refrigerator or 
freezer. Cannabis should be stored uncleaned, so that the glands containing the 
THC are not damaged, since damage causes their precious contents to be exposed 
to light and air. Marijuana should be cleaned only when it is about to be 
smoked. 
Many growers place a fresh lemon, orange, or lime peel in with each lid of 
stored grass. The peel helps to retain moisture, which keeps the buds pliable, 
and also gives the grass a pleasant bouquet. 
Most growers take well-earned pride in the quality of the marijuana that they 
grow. By supplying yourself with an herb which may play an important role in 
your life, you gain a feeling of self-sufficiency that can be infectious. 
Since your homegrown is well-tended and fresh, it has a sweet flavourful taste, 
far superior to that of commercial grass. And there need be no fear of 
contamination from herbicides, pesticides, adulterants, or other foreign matter. 
By growing your own, you come to the pleasant realisation that you are free from 
the vagaries and paranoia of the marijuana market - not to mention how little a 
home garden costs. All of these feeling can add up to a very heady experience. 
In a time of quiet contemplation, you might also reflect on the experiences that 
brought you this wondrous herb from a tiny seed. There is a tradition of mutual 
nurture and support between humanity and this plant that goes back 10,000 years. 

You are now part of this continuing tradition. 
As you probably realised while reading this book, some of the practical 
information came to us through letters from growers. We appreciate these letters 
and will continue to refer to them when we update and improve future editions of 
the Marijuana Grower's Guide. We would also like to hear ideas, criticisms, and 
feedback from our readers. Other research material and copies of professional 
research are also welcome. 
	Wishing you a Happy Harvest,
	Mel Frank
	Ed Rosenthal
BIBLIOGRAPHIC NOTES
Historical

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Botany

17.	Anderson, L.C. 1974. A Study of Systematic Wood Anatomy in Cannabis.
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38.	Masoud, A.N. Doorenbos, N.J., and Quimby, W.M. 1973.
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40.	Metcalfe, C.R., and Chalk, L. 1969. Cannabinaceae. In Anatomy of
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Cannabis Cultivation

61.	Agurell, S. 1970. Constituents of Male and Female Cannabis. In Joyce
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63.	Coffman, C.B., and Getner, W.A. 1975. Response of Cannabis sativa
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87.	Stark, K. 1977. Marijuana Potency (Working Papers). And/Or Press.
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88.	Stevens, M. 1975. How to Grow Marijuana Indoors Under Lights. 3d ed.
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89.	Superweed, M.J. 1970. Super Grass Grower Guide. 16pp. Stone Kingdom
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Sex Determination

93.	Arnoux, M., and Mathieu, G. 1969. Influence du milieu sur le
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95.	Borthwick, H.A., and Scully, N.J. 1954. Photoperiodic Responses of
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98.	Mackay, E.L. 1939. Sex Chromosomes of Cannabis sativa. Amer. J.
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99.	McPhee, H.C. 1924. The influence of the Environment on Sex in Hemp,
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100.	Molotkovskii, G., and Butnitskii, I.N. 1971. Morphological and
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101.	Menzel, M.Y. 1964. Meiotic Chromosomes of Monoecious Kentucky Hemp
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102.	Pritchard, F.J. 1916(7). Change of Sex in Hemp. J. Heredity
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103.	Ram, H.Y., and Jaiswal, V.S. 1972. Induction of Male Flowers on
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104.	Ram, H.Y., and Jaiswal, V.S. 1972. Sex Reversal in the Male Plants
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106.	Schaffner, J. H. 1926. The Change of Opposite to Alternate Phylotaxy
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Chemistry

108.	Allwardt, W.H., Babcock, P.A., Segelman, A.B., and Cross, J.M. 1972.
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109.	Augrill, S., and Nillson, J.L. G. 1972. The Chemistry and Biological
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110.	Crombie, L., and Crombie, W.M.L. 1975. Cannabinoid Bis-Homologues:
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111.	Davis, H.K., Jr., et al. 1970. The PReparation and Analysis of
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112.	Duke, E.L., and Reimann, B.E.F. 1973. The Extractability of the
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113.	Edery, H., Grunfield, Y., Ben-Zvi, Z., and Mechoulam, R. 1971.
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114.	Fairburn, J.W., and Leibman, J.A. 1973. The Extraction and
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115.	Fiechtl, J., and Spiteller, G. 1975. New Cannabinoids: Part 1.
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116.	Grinspoon, L. 1969. Marijuana. In Altered States of Awareness:
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117.	Grlic, Lj. 1964. A Study of Some Chemical Characteristics of the
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118.	Harvey, D.J. 1976. Characterization of the Butyl Homologues of THC,
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119.	Holley, J.H. Hadley, K.W., and Turner, C.E. 1975. Constituents of
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120.	Masoud, A.N., and Doorenbos, N.J. 1973. Mississippi-Grown Cannabis
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        Sci. 62 (2):313-315.
121.	Mechoulam, R., McCallum, N.K., and Burstein, S. 1976. Recent
        Advances in the Chemistry and Biochemistry of Cannbis. Chem. Rev.
        76(1):75-110.
122.	Mechoulam, R. 19733. Marijuana Chemistry, Pharmacology, Metabolism,
        and Clinical Effects. 409 pp. Academic Press. New York.
123.	Mechoulam, R. 1970. Marijuana Chemistry. Science
        168(3936):1159-1166.
124.	Mechoulam, R., and Gaoni, Y. 1967. Recent Afvances in the
        Chemistry of Hashish. Fortschritte Chem. Organ. Naturwiss.
        25:175-213.
125.	Mechoulam, R., and Gaoni, Y. 1965. Hashish, IV:The Isolation and
        Structure of Cannabinolic, Cannabidiolic, and Cannabigerolic Acids.
        Tetrahedron 121:1223-1229.
126.	Merkis, F. 1971. Cannabivarin and Tetracannabivarin: Two New
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Noncannabinoids of Cannabis

141.	El-Feraly, F.S., and Turner, C.E. 1975. Alkaloids of Cannabis
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142.	Ham, M.T., et al. 1973. Effects of Cannabis Roots on the Heart. J.
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144.	Hood, L. V. S., Dames, M.E., and Barry, G.T. 1973. Headspace
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151.	Mile, M. L., and Turner, C.E. 1973. Phytochemical Screening of
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158.	Stahl, E., and Kunde, R. 1973. Neue Inhaltsstoffe aus dem
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Storage/Smoking

161.	Agurell, S., and Leander, K. 1971. Stability, Transfer, and
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Pharmacology

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Miscellaneous

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201.	Bradshaw, A.D. 1972. Some of the Evolutionary Consequences of Being
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202.	Canham, A.E. 1966. Artificial Light in Horticulture. 212pp. Centrex
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203.	Chichilo, P., and Whittabker, C.W. 1961. Trace Elements in
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204.	Common Weeds of the United States. 1970. 463 pp. USDA. Washington,
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205.	Crombie, L., and Crombie, W.M.L. 1975. Cannabinoid Formation in
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206.	Devlin, R.M. 1969. Plant Physiology. 2d ed. 446 pp. Van Nostrand
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207.	DeWit, J.M.J., and Harian, J.R. 1975. Weeds and Domesticates:
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208.	Donahue, R.L., Shickluna, J.C., and Robertson, L.S. 1971. Soils:
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209.	Duke, W.B., Hagin, R.D., Hunt, J.F., and Lindscott, D.L. 1975.
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210.	Ehrlich, P.R., and Rayen, P.H. 1969. Differentiation of Populations.
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211.	Encyclopaedia Brittanica. 1894. Vol. III:627-628. Vol. XI:647-649,
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212.	Fenselau, C., Kelly, S., Salmon, M., and Billets, S. 1976. The
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213.	Getting the Bugs Out of Organic Gardening.  1973. 115 pp. Rodale
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214.	Golueke, C.G. 1972. Composting: A Study of the Process and its
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215.	Hall, A.D. 1912. Fertilisers and Manures. 384 pp. E.P. Dutton.
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216.	Harlan, J.R. 1976. The Plants and Animals that Nourish Man.
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217.	Henis, C.Y., and Mitchell, R. 1973. Effect of Biogenic Amines and
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218.	Lentz, P.L., Turner, C.E., Robertson, L.W., and Getner, W.A. 1974.
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219.	Levin, D.A. 1973. The Role of Trichomes in Plant Defense. Q. Rev.
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220.	McVickar, M.H., Bridger, G.L., and Nelson, L.B., eds. 1963.
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221.	Organic Fertilisers: Which Ones and How to Use Them. 1973. 129 pp.
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222.	Rorison, I.H., ed. 1969. Ecological Aspects of Mineral Nutrition in
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223.	Stevenson and Brown. 1918. Soil Survey of Iowa Report No. 2,
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224.	Stout, R., and Clemence, R. 1971. The Ruth Stout No-Work Garden
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225.	Sunset Western Garden Book. 1967. 448 pp. Lane Publishing. Menlo
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226.	Teuscher, H., and Adler, D. 1960. The Soil and its Fertility.
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227.	Thompson, L. 1957. Soils and Fertility. 2ed ed. 327 pp. McGraw-Hill,
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