MARIHUANA GROWERS HANDBOOK
MARIJUANA GROWERS HANDBOOK
In 1969, Richard Nixon initiated Operation Intercept, a pro-
gram designed to stem the flow of Mexican marijuana into this
country. The program forced Mexico to use paraquat on its mari-
juana fields. In similar actions, pressure was put on Thailand, Col-
ombia, and Jamaica to curtail imports to the U.S.
Domestic smokers became increasingly alarmed at the reports
of lung damage after smoking paraquat-sprayed marijuana. In fact,
at the time, Dr. Carlton Turner, currently President Reagan's Drug
Policy Advisor, developed a kit to determine whether the marijuana
a smoker had purchased was contaminated. In addition, infections
were reported from smoking imported marijuana which was con-
taminated by animal feces and mold.
In this climate of health fears and supply shortage, Ed Rosen-
thal and his colleague Mel Frank wrote Marijuana Grower's Guide,
which was the most monumentally successful book of its kind ever
published. Domestic cultivators took the technology found in Mari-
juana Grower's Guide and developed their own indoor and outdoor
plots, no longer willing to rely on foreign supply. The more the
government stepped up its eradication attempts aimed at imports,
the more mini-gardens and mini-farms began to develop in the U.S.
In simple-to-understand language, Marijuana Grower's Guide made
experts out of gardening hobbyists.
Marijuana cultivation technology has accelerated since Mari-
juana Grower's Guide was written. Advances in lighting
technology, hydroponics and propagation left a void of serious
literature on the subject. Marijuana Growers Handbook is a com-
pletely new book which covers all phases of cultivation, including
Most experts agree that U.S. growers are the finest in the
world. They can get a good yield from the smallest space and have
developed hybrids of incredible quality. This indicates that many
growers use sophisticated techniques. This book was written to help
these people with their gardens, as well as helping novices who are
growing for the first time.
The Wall Street Journal recently estimated that there are bet-
ween 20 and 30 million regular users of marijuana in this country.
Other sources put the figure at 50,000,000 users of marijuana in this
country. High Times calculates that 50% of the marijuana used in
this country is domestic. Marijuana will not go away.
Cowardly and reactionary politicians who have maintained
prohibition will soon see marijuana legalized. Realistic politicians
who see the damage that the marijuana laws have done to the socie-
ty will change the laws so that they can tax and regulate marijuana.
Only homegrowers will be free of the market and government
regulation. We are ready for legalization, too. We have the
technology for growing superior marijuana and the tools for doing
Marijuana prohibition was initiated because of the people who
smoked it. The laws continue in effect today for those same
reasons. Politicians don't like people who think for themselves, are
independent, and who recognize bullshit. They would prefer for
each citizen to become a subject, a ward of the state, who is depen-
dent on government for making his/her life decisions. Marijuana
tends to let us develop different sets and set perceptions, to see the
world a little differently. To change not only what we think but how
we think. That's what scares the regulators.
It is a felony to cultivate marijuana in 49 of the 50 states (it is
legal in Alaska). It is legal or tolerated in only a few countries:
Holland, India, and Nepal.
Growers use precaution when setting up their gardens. They
make sure that their activity arouses no suspicion and that the
garden and its contents cannot be seen by unintended observers.
Artificial lighting, usually the main source of light for indoor
gardeners, can draw quite a bit of electricity. Electrical systems
should be adequate to support the electrical draw. If a large amount
of electricity is used, the utility company may investigate the situa-
tion for shorts or other drains, including a surreptitious garden.
Growers are circumspect about discussing their gardens. The
smartest ones use only the "need to know theory" - that anyone
who doesn't need to know doesn't know. Envy, jealousy, and even
misplaced morality have made informers of ex-friends.
Marijuana: The Plant
Cannabis probably evolved in the Himalayan foothills, but its
origins are clouded by the plant's early symbiotic relationship with
humans. It has been grown for three products-the seeds, which are
used as a grainlike food and animal feed and for oil; its fiber, which
is used for cloth and rope; and its resin, which is used medically and
recreationally since it contains the group of psychoactive substances
collectively known as Tetra-hydrocannibinol, usually referred to as
THC. Plants grown for seed or fiber are usually referred to as hemp
and contain small amounts of THC. Plants grown for THC and for
the resin are referred to as marijuana.
Use of cannabis and its products spread quickly throughout
the world. Marijuana is now cultivated in climates ranging from the
Arctic to the equator. Cannabis has been evolving for hundreds of
thousands of generations on its own and through informal breeding
programs by farmers. A diverse group of varieties has evolved or
been developed as a result of breeders attempts to create a plant
that is efficient at producing the desired product, which flourishes
under particular environmental conditions.
Cannabis easily escapes from cultivation and goes "wild". For
instance, in the American midwest, stands of hemp "weed" remain
from the 1940's plantings. These plants adapt on a population level
to the particular environmental conditions that the plants face; the
stand's genetic pool, and thus the plants' characteristics, evolve
over a number of generations.~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Varieties differ in growth characteristics such as height, width,
branching traits, leaf size, leaf shape, flowering time, yield, poten-
cy, taste, type of high, and aroma. For the most part, potency is a
factor of genetics. Some plants have the genetic potential of pro-
ducing high grade marijuana and others do not. The goal of the
cultivator is. to allow the high THC plants to reach their full
Marijuana is a fast growing annual plant, although some
varieties in some warm areas over winter. It does best in a well-
drained medium, high in fertility. It requires long periods of
unobstructed bright light daily. Marijuana is usually dioecious;
plants are either male or female, although some varieties are
monoecious - they have male and female flowers on the same
Marijuana's annual cycle begins with germination in the early
spring. The plant grows vigorously for several months. The plant
begins to flower in the late summer or early fall and sets seed by late
fall. The seeds drop as the plant dies as a result of changes in the
Indoors, the grower has complete control of the environment.
The cultivator determines when the plants are to be started, when
they will flower, whether they are to produce seed and even if they
are to bear a second harvest.
Choosing A Variety
Gardeners can grow a garden with only one or two varieties or
a potpourri. Each has its advantages. Commercial growers usually
prefer homogeneous gardens because the plants taste the same and
mature at the same time. These growers usually choose fast matur-
ing plants so that there is a quick turnaround. Commercial growers
often use clones or cuttings from one plant so that the garden is
genetically identical; the clones have exactly the same growth habits
Homegrowers are usually more concerned with quality than
with fast maturity. Most often, they grow mixed groups of plants so
they have a selection of potency, quality of the high, and taste.
Heterogeneous gardens take longer to mature and have a lower
yield than homogeneous gardens. They take more care too, because
the plants grow at different rates, have different shapes and require
varying amounts of space. The plants require individual care.
Marijuana grown in the United States is usually one of two
main types: indica or sativa. Indica plants originated in the Hindu-
Kush valleys in central Asia, which is located between the 25-35
latitudes. The weather there is changeable. One year there may be
drought, the next it might be cloudy, wet, rainy or sunny. For the
population to survive, the plant group needs to have individuals
which survive and thrive under different conditions. Thus, in any
season, no matter what the weather, some plants will do well and
some will do poorly.
Indica was probably developed by hash users for resin content,
not for flower smoking. The resin was removed from the plant. An
indication of indica's development is the seeds, which remain
enclosed and stick to the resin. Since they are very hard to discon-
nect from the plant, they require human help. Wild plants readily
drop seeds once they mature.
Plants from the same line from equatorial areas are usually
fairly uniform. These include Colombians and central Africans.
Plants from higher latitudes of the same line sometimes have very
different characteristics. These include Southern Africans, Nor-
thern Mexicans, and indicas. The plants look different from each
other and have different maturities and potency. The ratio of THC
(the ingredient which is psychoactive) to CBD (its precursor, which
often leaves the smoker feeling disoriented, sleepy, drugged or con-
fused) also varies.
High latitude sativas have the same general characteristics as
other sativas: conical form, long bladed leaves, wide spacing be-
tween branches, and vigorous growth.
Indicas do have some broad general characteristics: they tend
to mature early, have compact short branches and wide, short
leaves which are dark green, sometimes tinged purple.
Indica buds are usually tight, heavy, wide and thick rather than
long. They smell "stinky", "skunky", or "pungent" and their
smoke is thick - a small toke can induce coughing. The best in-
dicas have a relaxing "social high" which allow one to sense and
feel the environment but do not lead to thinking about or analyzing
Cannabis sativa plants are found throughout the world. Potent
varieties such as Colombian, Panamanian, Mexican, Nigerian,
Congolese, Indian and Thai are found in equatorial zones. These
plants require a long time to mature and ordinarily grow in areas
where they have a long season. They are usually very potent, con-
taining large quantities of THC and virtually no CBD. They have
long, medium4hick buds when they are grown in full equatorial
sun, but under artificial light or even under the temperate sun, the
buds tend to run (not fill out completely). The buds usually smell
sweet or tangy and the smoke is smooth, sometimes deceptively so.
The THC to CBD ratio of sativa plants gets lower as the plants
are found further from the equator. Jamaican and Central Mexican
varieties are found at the 1 5-2Oth latitudes. At the 3Oth latitude,
varieties such as Southern African and Northern Mexican are
variable and may contain equal amounts of THC and CBD, giving
CHART 2-1: The Varieties at a Glance
Variety Maturity Outdoor Size Branching Pattern Bud Type Aroma High Buds Color Comments
(in feet) Density of Bud (flowers)
Height Width Indoors
Afghani mid- 4-8 3-6 squat, compact, thick, heavy heavy, rounded, dark The standard corn-
& Kush Sept. short sidebranches, dense, pungent, tiring, dense green, mercial plant. Quality
-Oct. thick webbed leaves short, skunky- stupefying purple varies within
rounded fruity population.
Colombian late 7-12 4-7 conical, X-mas med. thick, sweet, spacy, Tends to run green, Rarely seen commer
Nov.-Jan. tree, long branches 4-8" long, fruity, thought- long flower some red cially. Needs lots of
at bottom, tapering light to light provoking, stem, sparse light and warmth to
at the top, thin long medium strong flowered develop thick colas.
leaves density _________ ____________________
Indian mid Nov.- 8-12 4-6 long internodes, big big, thick, med strong, large fluffy light Will run without
(Central) mid Dec. leaves, strong firm 7-12" long; fruity- active, buds green, intense light.
branches, elongated light-wt. skunky social red Susceptible to
conical shape flowers on pistils fusarium wilt.
Jamaican late 6-10 3-6 conical, but squat- long thin light, medium, thin, long runs light Adaptable, good
Oct.-Dec. ter than Col. Med. colas sweet, active, under low light green weather resistance.
leaves, medium w/buds musky social Susceptible to
branching 11/2 "-3" fusarium wilt.
Mexican Oct.-early 8-15 41/2-9 elongated long, thin light, weak, long thin light Vigorous plants, fast
(Northern) Nov. X-mas tree, long 12"-24" sweet slightly mature well green, starters. Some cold-
branches, medium- colas perfume, heavy, red resistance.
sized leaves spicy sleepy
Mexican Nov.-Dec. 8-14 4 1/2-9 shorter than long thin sweet comes on long, thin, may very' light Hybridizes well with
(Southern) northern 12 "-18" quick; run a little colored, Afghani.
colas intense, red hairs
Moroccan Aug.- 4-9 21/2-5 some sidebranching, thick, round med. weak, thin buds dark Good breeding
Sept. but most effort in ed, 3"-6" sweet to buzzy mature easily green material, lots of
tops long skunky variation.
Nigerian mid 6-12 4-7 X-mas tree with med. thick, dry- very thick, med. medium Vigorous warm
Nov.-mid strong side dense; runs sweet, strong, length, may green weather plant. Needs
Dec. branches; long, in low light perfume bell- run; needs light to mature.
highly serrated musk ringing, lots of light
Thai Dec.-Jan. 5-9 4-8 asymmetrical, long dense, medium, strong fluffy, medium Many hermaphodites
and con- branches seek open under high dry- druggy, mature Se- green make growing hard.
tinuing space light runs sweet, has energ quentially Buds ripen but plant
otherwise spicy over months sends out new
Southern Aug.- 5-9 4-6 elongated conical med. thick, heavy uplifting, thin buds light Very variable. Good
African Oct. lower branches may be sweet to social mature easily green breeding material.
angle up sharply; somewhat spicy
thin-bladed leaves loose &
often heavily leafy
All of the descriptions are tentative guidelines. They are affected by cultivation technique, microenvironmental conditions, variations in climate, nutrients
available, latitude and other factors. Often, several distinctive varieties can be found in the same areas. The most common varieties are described.
the smoker a buzzy, confusing high. These plants are used mostly
for hybridizing. Plants found above the 3oth latitude usually have
low levels of THC, with high levels of CBD and are considered
If indica and sativa varieties are considered opposite ends of a
spectrum, most plants fall in between the spectrum. Because of
marijuana and hemp's long symbiotic relationship with humans,
seeds are constantly procured or traded so that virtually all popula-
tions have been mixed with foreign plants at one time or another.
Even in traditional marijuana-growing countries, the mari-
juana is often the result of several crossed lines. Jamaican ganja,
for example, is probably the result of crosses between hemp, which
the English cultivated for rope, and Indian ganja, which arrived
with the Indian immigrants who came to the country. The term for
marijuana in Jamaica is ganja, the same as in India. The traditional
Jamaican term for the best weed is Kali, named for the Indian killer
Growth and Flowering
The cannabis plant regulates its growth and flowering stages by
measuring changes in the number of hours of uninterrupted
darkness to determine when to flower. The plant produces a hor-
mone (phytochrome) beginning at germination. When this chemical
builds up to a critical level, the plant changes its mode from
vegetative growth to flowering. This chemical is destroyed in the
presence of even a few moments of light. During the late spring and
early summer there are many more hours of light than darkness and
the hormone does not build up to a critical level. However, as the
days grow shorter and there are longer periods of uninterrupted
darkness, the hormone builds to a critical level.
Flowering occurs at different times with different varieties as a
result of the adaption of the varieties to the environment. Varieties
from the 3oth latitude grow in an area with a temperate climate and
fairly early fall. These plants usually trigger in July or August and
are ready to harvest in September or October. Southern African
varieties often flower with as little as 8 or 9 hours of darkness/15 to
16 hours of light. Other 3oth latitude varieties including most in-
dicas flower when the darkness cycle lasts a minimum of 9 to 10
hours. Jamaican and some Southeast Asian varieties will trigger at
11 hours of darkness and ripen during September or October.
Equatorial varieties trigger at 12 hours or more of darkness.
This means that they will not start flowering before late September
or early October and will not mature until late November or early
Of course, indoors the plants' growth stage can be regulated
with the flick of a switch. Nevertheless, the plants respond to the ar-
tificial light cycle in the same way that they do to the natural
The potency of the plant is related to its maturity rather than
Chronological age. Genetically identical 3 month and 6 month-old
plants which have mature flowers have the same potency. Starting
from seed, a six month old plant flowers slightly faster and fills out
more than a 3 month old plant.
Choosing a Space
Almost any area can be converted to a growing space. Attics,
basements, spare rooms, alcoves and even shelves can be used.
Metal shacks, garages and greenhouses are ideal areas. All spaces
must be located in an area inaccessible to visitors and invisible from
The ideal area is at least 6 feet high, with a minimum of 50
square feet, an area about 7 by 7 feet. (Square footage is computed
by multiplying length times width.) A single 1,000 watt metal halide
or sodium vapor lamp, the most efficient means of illuminating a
garden, covers an area this size.
Gardeners who have smaller spaces, at least one foot wide and
several feet long, can use fluorescent tubes, 400 watt metal halides,
or sodium vapor lamps.
Gardeners who do not have a space even this large to spare can
use smaller areas (See the chapter "Novel Gardens").
Usually, large gardens are more efficient than small ones.
The space does not require windows or outside ventilation, but
it is easier to set up a space if it has one or the other.
Larger growing areas need adequate ventilation so that heat,
oxygen, and moisture levels can be controlled. Greenhouses usually
have vents and fans built in. Provisions for ventilation must be
made for lamp-lit enclosed areas. Heat and moisture buildup can be
extraordinary. During the winter in most areas, the heat is easily
dissipated; however, the heat buildup is harder to deal with in hot
weather. Adequate ventilation and air coolers are the answer.
Preparing the Space
The space is the future home and environment of the plants. It
should be cleaned of any residue or debris which might house in-
sects, parasites or diseases. If it has been contaminated with plant
pests it can be sprayed or wiped down with a 5 % bleach solution
which kills most organisms. The room must be well-ventilated when
this operation is going on. The room will be subject to high humidi-
ty so any materials such as clothing which might be damaged by
moisture are removed.
Since the plants will be watered, and water may be spilled, the
floors and any other areas that may be water damaged should be
covered with linoleum or plastic. High grade 6 or 8 mil polyethylene
drop cloths or vinyl tarps protect a floor well. The plastic should be
sealed with tape so that no water seeps to the floor.
The amount of light delivered to the plant rises dramatically
when the space is enclosed by reflective material. Some good reflec-
tive materials are flat white paint, aluminum (the dull side so that
the light is diffused), white cardboard, plywood painted white,
white polyethylene, silvered mylar, gift wrap, white cloth, or
silvered plastic such as Astrolon. Materials can be taped or tack-
ed onto the walls, or hung as curtains. All areas of the space should
be covered with reflective material. The walls, ceiling and floors are
all capable of reflecting light and should be covered with reflective
material such as aluminum foil. It is easiest to run the material ver
tically rather than horizontally.
Experienced growers find it convenient to use the wide, heavy
duty aluminum foil or insulating foil (sold in wide rolls) in areas
which will not be disturbed and plastic or cloth curtains where the
material will be moved.
Windows can be covered with opaque material if a bright light
emanating from the window would draw suspicion. If the window
does not draw suspicion and allows bright light into the room, it
should be covered with a translucent material such as rice paper,
lace curtains, or aquarium crystal paint.
Garages, metal buildings, or attics can be converted to
lighthouses by replacing the roof with fiberglass greenhouse
material such as Filon~. These translucent panels permit almost all
the light to pass through but diffuse it so that there is no visible im-
age passing out while there is an even distribution of light coming
in. A space with a translucent roof needs no artificial lighting in the
summer and only supplemental lighting during the other seasons.
Overhead light entering from a skylight or large window is very
helpful. Light is utilized best if it is diffused.
Concrete and other cold floors should be covered with in-
sulating material such as foam carpet lining, styrofoam sheeting,
wood planks or wooden palettes so that the plant containers and the
roots are kept from getting cold.
Plant Size and Spacing
- Manjuana varieties differ not Oflly in their growth rate, but
also in their potential size. The grower also plays a role in determin-
log the size of the plants because the plants can be induced to flower
at any age or size just by regulating the number of hours of uninter-
rupted darkness that the plants receive.
Growers have different ideas about how much space each plant
needs. The closer the plants are spaced, the less room the individual
plant has to grow. Some growers use only a few plants in a space,
and they grow the plants in large containers. Other growers prefer
to fill the space with smaller plants. Either method works, but a
gar den with smaller plants which fills the space more completely
probably yields more in less time. The total vegetative growth in a
Worn containing many small sized plants is greater than a room
co ntaining only a few plants. Since each plant is smaller, it needs
less time to grow to its desired size. Remember that the gardener is
in terested in a crop of beautiful buds, not beautiful plants.
The amount of space a plant requires depends on the height the
plants are to grow. A plant growing 10 feet high is going to be wider
than a 4 foot plant. The width of the plant also depends on cultiva-
don practices. Plants which are pruned grow wider than unpruned
plants. The different growth characteristics of the plants also affect
die space required by each plant. In 1-or 2-light gardens, where the
plants are to grow no higher than 6 feet, plants are given between 1
and 9 square feet of space. In a high greenhouse lit by natural light,
Where the plants grow 10-12 feet high, the plants may be given as
m uch as 80 to 100 square feet.
One of the first books written on indoor growing suggested
that the entire floor of a grow room be filled with soil. This method
is effective but unfeasible for most cultivators. Still, the growers
have a wide choice of growing mediums and techniques; they may
choose between growing in soil or using a hydroponic method.
Most growers prefer to cultivate their plants in containers filled
with soil, commercial mixes, or their own recipe of soil, fertilizers,
and soil conditioners. These mixes vary quite a bit in their content,
nutrient values, texture, pH, and water-holding capacity.
Potting soil is composed of topsoil, which is a natural outdoor
composite high in nutrients. It is the top layer of soil, containing
large amounts of organic material such as humus and compost as
well as minerals and clays. Topsoil is usually lightened up so that it
does not pack. This is done using sand, vermiculite, perlite, peat
moss and/or gravel.
Potting soil tends to be heavy, smell earthy and have a rich
dark color. It can supply most of the nutrients that a plant needs for
the first couple of months.
Commercial potting mixes are composites manufactured from
ingredients such as bark or wood fiber, composts, or soil condi-
tioners such as vermiculite, perlite and peat moss. They are design-
ed to support growth of houseplants by holding adequate amounts
of water and nutrients and releasing them slowly. Potting mixes
tend to be low in nutrients and often require fertilization from the
outset. Many of them may be considered hydroponic mixes because
the nutrients are supplied by the gardener in a water solution on a
Texture of the potting mix is the most important consideration
for containerized plants. The mixture should drain well and allow
air to enter empty spaces so that the roots can breathe oxygen.
Mixes which are too fine may become soggy or stick together,
Preventing the roots from obtaining the required oxygen. A soggy
Condition also promotes the growth of anaerobic bacteria which
release acids that eventually harm the roots.
A moist potting mix with good texture should form a clump if
it is squeezed in a fist; then with a slight poke the clod should break
up. If the clod stays together, soil conditioners are required to
loosen it up. Vermiculite, perlite or pea-sized styrofoam chips will
serve the purpose. Some growers prefer to make their own mixes.
These can be made from soil, soil conditioners and fertilizers.
Plants grown in soil do not grow as quickly as those in
hydroponic mixes. However many growers prefer soil for aesthetic
reasons. Good potting mixes can be made from topsoil fairly easily.
Usually it is easier to buy topsoil than to use unpasteurized top-
soil which contains weed seeds, insects and disease organisms. Out-
doors, these organisms are kept in check, for the most part, by the
forces of nature. Bringing them indoors, however, is like bringing
them into an incubator, where many of their natural enemies are
not around to take care of them. Soil can be sterilized using a 5%
bleach solution poured through the medium or by being steamed
for 20 minutes. Probably the easiest way to sterilize soil is to use a
microwave. It is heated until it is steaming - about 5 minutes for a
gallon or more.
Potting soils and potting mixes vary tremendously in composi-
tion, pH and fertility. Most mixes contain only small amounts of
soil. If a package is marked "potting soil", it is usually made most-
ly from topsoil.
If the soil clumps up it should be loosened using sand, perlite
or styrofoam. One part amendment is used to 2-3 parts soil. Ad-
ditives listed in Chart 7-2 may also be added. Here is a partial list of
Foam rubber can be used in place of styrofoam. Although it
holds water trapped between its open cells it also holds air. About
1.5 parts of foam rubber for every part of styrofoam is used. Pea-
size pieces or smaller should be used.
Gravel is often used as a sole medium in hydroponic systems
because it is easy to clean, never wears out, does not "lock up"
nutrients, and is inexpensive. It is also a good mix ingredient
because it creates large spaces for airpockets and gives the mix
weight. Some gravel contains limestone (see "Sand"). This material
should not be used.
Lava is a preferred medium on its own or as a part of a mix. It
is porous and holds water both on its surface and in the irregular
spaces along its irregular shape. Lava is an ideal medium by itself
but is sometimes considered a little too dry. To give it more
moisture-holding ability, about one part of wet vermiculite is mixed
with 3 to 6 parts lava. The vermiculite will break up and coat the
lava, creating a medium with excellent water-holding abilities and
plenty of air spaces. If the mix is watered from the top, the ver-
miculite will wash down eventually, but if it is watered from the
bottom it will remain.
Perlite is an expanded (puffed) volcanic glass. It is lightweight
with many peaks and valleys on its surface, where it traps particles
of water. However, it dQes not absorb water into its structure. It
does not break down easily and is hard to the touch. Perlite comes
in several grades with the coarser grade being better for larger con-
tainers. Perlite is very dusty when dry. To eliminate dust, the
material is watered to saturation with a watering can or hose before
it is removed from the bag. Use of masks and respirators is impor-
Rockwool is made from stone which has been heated then ex-
truded into thin strands which are something like glass wool. It ab-
sorbs water like a wick. It usually comes in blocks or rolls. It can be
used in all systems but is usually used in conjunction with drip emit-
ters. Growers report phenomenal growth rates using rockwool. It is
also very convenient to use. The blocks are placed in position or it is
rolled out. Then seeds or transplants are placed on the material.
Sand is a heavy material which is often added to a mixture to
increase its weight so that the plant is held more firmly. It promotes
drainage and keeps the mix from caking. Sand comes in several
grades too, but all of them seem to work well. The best sand to use
is composed of quartz. Sand is often composed of limestone; the
limestone/sand raises pH, causing micronutrients to precipitate,
making them unavailable to the plants. It is best not to use it.
Limestone-containing sand can be "cured" by soaking in a
solution of water and superphosphate fertilizer which binds with
the surface of the lime molecule in the sand, making the molecule
temporarily inert. One pound of superphosphate is used to S
gallons of water. It dissolves best in hot water. The sand should sit
in this for 6-12 hours and then be rinsed. Superphosphate can be
purchased at most nurseries.
Horticultural sand is composed of inert materials and needs no
curing. Sand must be made free of salt if it came from a salt-water
Sphagnum or peat moss is gathered from bogs in the midwest.
It absorbs many times its own weight in water and acts as a buffer
for nutrients. Buffers absorb the nutrients and hold large amounts
in their chemical structure. The moss releases them gradually as
they are used by the plant. If too much nutrient is supplied, the
moss will act on it and hold it, preventing toxic buildups in the
water solution. Moss tends to be acidic so no more than 20% of the
planting mix should be composed of it.
Styrofoam is a hydrophobic material (it repels water) and is an
excellent soil mix ingredient. It allows air spaces to form in the mix
and keeps the materials from clumping, since it does not bond with
other materials or with itself. One problem is that it is lighter than
water and tends to migrate to the top of the mix. Styrofoam is easily
used to adjust the water-holding capacity of a mix. Mixes which are
soggy or which hold too much water can be "dried" with the addi-
tion of styrofoam. Styrofoam balls or chips no larger than a pea
should be used in fine4extured mixtures. Larger styrofoam pieces
can be used in coarse mixes.
Vermiculite is processed puffed mica. It is very lightweight but
holds large quantities of water in its structure. Vermiculite is
available in several size pieces. The large size seems to permit more
aeration. Vermiculite breaks down into smaller particles over a
period of time. Vermiculite is sold in several grades based on the
size of the particles. The fine grades are best suited to small con-
tainers. In large containers, fine particles tend to pack too tightly,
not leaving enough space for air. Coarser grades should be used in
larger containers. Vermiculite is dusty when dry, so it should be wet
down before it is used.
Mediums used in smaller containers should be able to absorb
more water than mediums in larger containers. For instance, seed-
lings started in 1 to 2 inch containers can be planted in plain ver-
miculite or soil. Containers up to about one gallon can be filled
with a vermiculite-perlite or soil-perlite mix. Containers larger than
that need a mix modified so that it does not hold as much water and
does not become soggy. The addition of sand, gravel, or styrofoam
accomplishes this very easily.
Here are lists of different mediums suitable for planting: Below
is a list of the moist mixtures, suitable for the wick system, the
reservoir system and drip emitters which are covered in Chapter 9.
CHART 7-1-A: MOIST PLANTING MIXES
1) 4 parts topsoil, 1 part vermiculite, 1 part perlite. Moist, con-
tains medium-high amounts of nutrients. Best for wick and hand-
2) 3 parts topsoil, 1 part peat moss, 1 part vermiculite, 1 part
perlite, 1 part styrofoam. Moist but airy. Medium nutrients. Best
for wick and hand-watering.
3)3 parts vermiculite, 3 parts perlite, 1 part sand, 2 parts pea-
sized gravel. Moist and airy but has some weight. Good for all
systems, drains well.
4) 5 parts vermiculite, S parts perlite. Standard mix, moist. Ex-
cellent for wick and drip emitter systems though it works well for all
5) 3 parts vermiculite, 1 part perlite, 1 part styrofoam. Medium
dry mix, excellent for all systems.
6) 2 parts vermiculite, 1 part perlite, 1 part styrofoam, 1 part
peat moss. Moist mix.
7) 2 parts vermiculite, 2 parts perlite, 3 parts styrofoam, 1 part
sphagnum moss, 1 part compost. Medium moisture, small amounts
of slow-releasing nutrients, good for all systems.
8) 2 parts topsoil, 2 parts compost, 1 part sand, 1 part perlite.
Medium-moist, high in slow-release of organic nutrients, good for
wick and drip systems, as well as hand watering.
9) 2 parts compost, 1 part perlite, 1 part sand, 1 part lava.
Drier mix, high in slow-release of nutrients, drains well, good for all
10)1 part topsoil, 1 part compost, 2 parts sand, 1 part lava.
Dry mix, high in nutrients, good for all systems.
11) 3 parts compost, 3 parts sand, 2 parts perlite, 1 part peat
moss, 2 parts vermiculite. Moist, mid-range nutrients, good for
12) 2 parts compost, 2 parts sand, 1 part styrofoam. Drier,
high nutrients, good for all systems.
13) 5 parts lava, 1 part vermiculite. Drier, airy, good for all
Here are some drier mediums suitable for flood systems as well as
drip emitters hydroponic systems (covered in Chapter 9).
CHART 7-1-B: FLOOD SYSTEM/DRIP EMITTER MIXES
2) Pea size gravel
4) Mixes of any or all of the above
Manure and other slow-releasing natural fertilizers are often
added to the planting mix. With these additives, the grower needs to
use fertilizers only supplementally. Some of the organic amend-
ments are listed in the following chart. Organic amendments can be
mixed but should not be used in amounts larger than those recom-
mended because too much nutrient can cause toxicity.
Some growers add time-release fertilizers to the mix. These are
formulated to release nutrients over a specified period of time,
usually 3, 4, 6 or 8 months. The actual rate of release is regulated in
part by temperature, and since house temperatures are usually
higher than outdoor soil temperatures, the fertilizers used indoors
release over a shorter period of time than is noted on the label.
Gardeners find that they must supplement the time-release fer-
tilizer formulas with soluble fertilizers during the growing season.
Growers can circumvent this problem by using a time-release fer-
tilizer suggested for a longer period of time than the plant cycle. For
instance, a 9 month time-release fertilizer can be used in a 6 month
garden. Remember that more fertilizer is releasing faster, so that a
larger amount of nutrients will be available than was intended.
These mixes are used sparingly.
About one tablespoon of dolomite limestone should be added
for each gallon of planting mix, or a half cup per cubic foot of mix.
This supplies the calcium along with magnesium, both of which the
plants require. If dolomite is unavailable, then hydrated lime or any
agricultural lime can be used.
CHART 7-2: ORGANIC AMENDMENTS
AMENDMENT N P K 1 Part in X Parts Mix
COW MANURE 1.5 .85 1.75 Excellent conditioner,
breaks down over the
growing season. 1 part in
10 parts mix.
CHICKEN MANURE 3 1.5 .85 Fast acting. 1 part in 20
BLOOD MEAL 15 1.3 .7 N quickly available. 1 part
in 100 parts mix.
DRIED BLOOD 13 3 0 Very soluble. 1 part in 100
WORM CASTINGS 3 1 .5 Releases N gradually. 1
part in 15 parts mix.
GUANO 2-8 2-5 .5-3 Varies a lot, moderately
soluble. For guano
containing 20/0 nitrogen, 1
part in 15 parts mix. For
8% nitrogen, 1 part in 40
COTTONSEED MEAL 6 2.5 1.5 Releases N gradually. 1
part in 30 parts mix.
GREENSAND 0 1.5 5 High in micronutrients.
Nutrients available over the
season. 1 part in 30 parts
FEATHERS 15 ? ? Breaks down slowly. 1 part
in 75 parts mix.
HAIR 17 ? ? Breaks down slowly. 1 part
in 75 parts mix.
N = Nitrogen e p = Phosphorous e K = Potassium
Hydroponics vs. Soil Gardening
Plants growing in the wild outdoors obtain their nutrients from
the breakdown of complex organic chemicals into simpler water-
soluble forms. The roots catch the chemicals using a combination
of electrical charges and chemical manipulation. The ecosystem is
generally self-supporting. For instance, in some tropical areas most
of the nutrients are actually held by living plants. As soon as the
vegetation dies, bacteria and other microlife feast and render the
nutrients water-soluble. They are absorbed into the soil and are
almost immediately taken up by higher living plants.
Farmers remove some of the nutrients from the soil when they
harvest their crops. In order to replace those nutrients they add fer-
tilizers and other soil additives.
Gardeners growing plants in containers have a closed ecology
system. Once the plants use the nutrients in the medium, their
growth and health is curtailed until more nutrients become available
to them. It is up to the grower to supply the nutrients required by
the plants. The addition of organic matter such as compost or
manure to the medium allows the plant to obtain nutrients for a
while without the use of water-soluble fertilizers. However, once
these nutrients are used up, growers usually add water-soluble
nutrients when they water. Without realizing it, they are gardening
hydroponically. Hydroponics is the art of growing plants, usually
without soil, using water-soluble fertilizers as the main or sole
source of nutrients. The plants are grown in a non-nutritive
medium such as gravel or sand or in lightweight materials such as
perlite, vermiculite or styrofoam.
The advantages of a hydroponic system over conventional hor-
ticultural methods are numerous: dry spots, root drowning and
soggy conditions do not occur. Nutrient and pH problems are large-
ly eliminated since the grower maintains tight control over their
concentration; there is little chance of "lockup" which occurs when
the nutrients are fixed in the soil and unavailable to the plant; plants
can be grown more conveniently in small containers; and owing to
the fact that there is no messing around with soil, the whole opera-
tion is easier, cleaner, and much less bothersome than when using
conventional growing techniques.
PASSIVE HYDROPONIC SYSTEMS
Most hydroponic systems fall into one of two broad categories:
passive or active. Passive systems such as reservoir or wick setups
depend on the molecular action inherent in the wick or medium to
make water available to the plant. Active systems which include the
flood, recirculating drip and aerated water systems, use a pump to
send nourishment to the plants.
Most commercially made "hobby" hydroponic systems
designed for general use are shallow and wide, so that an intensive
garden with a variety of plants can be grown. But most marijuana
growers prefer to grow each plant in an individual container.
The Wick System
The wick system is inexpensive, easy to set up and easy to
maintain. The principle behind this type of passive system is that a
length of 3/8 to 78 inch thick braided nylon rope, used as a wick, will
draw water up to the medium and keep it moist. The container,
which can be an ordinary nursery pot, holds a rooting medium and
has wicks running along the bottom, drooping through the holes at
the bottom, reaching down to the reservoir. Keeping the holes in the
container small makes it difficult for roots to penetrate to the reser-
voir. The amount of water delivered to the medium can be increas-
ed by increasing the number, length, or diameter of the wicks in
contact with the medium.
A 1 gallon container needs only a single wick, a three gallon
container should have two wicks, a five gallon container, three
'wicks. The wick system is self-regulating; the amount of water
delivered depends on the amount lost through evaporation or
Each medium has a maximum saturation level. Beyond that
point, an increase in the number of wicks will not increase the
moisture level. A 1-1-I combination of vermiculite, perlite, and
styrofoam is a convenient medium because the components are
lightweight and readily available. Some commercial units are sup-
plied with coarse vermiculite. To increase weight so that the plant
will not tip the container over when it gets large, some of the perlite
in the recipe can be replaced with sand. The bottom inch or two of
the container should be filled only with vermiculite, which is very
absorbent, so that the wicks have a good medium for moisture
Wick systems are easy to construct. The wick should extend S
inches or more down from the container. Two bricks, blocks of
wood, or styrofoam are placed on the bottom of a deep tray (a
plastic tray or oil drip pan will do fine.) Then the container is placed
on the blocks so that the wicks are touching the bottom of the tray.
The tray is filled with a nutrient/water solution. Water is replaced
in the tray as it evaporates or is absorbed by the medium through
A variation of this system can be constructed using an addi-
tional outer container rather than a tray. With this method less
water is lost due to evaporation.
To make sure that the containers fit together and come apart