closure of the stomates, and C02 can no longer
be absorbed from the air. From experiments with cannabis, a
C02 concentration of 1,300 ppm
(or 1,000 ppm above normal atmospheric concentrations)
produces an increase in
photosynthesis and carbohydrate production. It is also
necessary to examine calculation of
the growth chamber volume, and of the delivery rate of the
gas regulator, to determine the
precise amount of C02 required. Oxygen Oxygen is essential
for normal root development. In
nature, when rain is absorbed into the ground, oxygen is
drawn down around the roots. With
water culture, oxygen must be supplied continuously by
aeration. This is done by the use
of an aquarium air pump. Lack of aeration leads to root rot
and infections, impedes new
root formations, and increases the excretion of organic
compounds (such as carboxylic
acid, which reduces pH). Moreover, with insufficient
aeration, it is impossible for
ammoniacal nitrogen, calcium nitrate, and potassium to be
absorbed properly. Iron
deficiency may also result. Accumulation of carbon dioxide,
excreted by the roots in
non-aerated solutions, depresses absorption of nutrients and
water, which leads to
stunting and to abnormal enlargement of the roots. Aeration
is essential to any successful
water culture technique. Carbon dioxide (C02) is a
colorless, odorless gas found in the
air. Under normal circumstances, including the conditions
growers deal with, it is totally
harmless. Each molecule consists of one part carbon and two
parts oxygen. C02 is often
generated in the home. when a stove or water heater burns
gas it produces water vapor and
CO2. Plants use C02 as a raw material during the process of
photosynthesis C02 is quickly
used up in a well lit enclosed space. Until it is replaced,
the process cannot continue.
The availability of C02 to the plant can be a limiting
factor in photosynthesis and plant
growth Keeping the door or curtain of a small grow room open
helps tremendously because a
whole side of the grow space is exposed to external air. An
open door in a large a room
gives a much smaller ratio of interface, since the
percentage of the perimeter serving as
a vent is much smaller. C02 constitutes about .03%, or 300
parts per million of air in
country areas and about .035-.04% in industrialized regions.
Photosynthesis and growth
could proceed at a much higher rate if the amount of C02
available were increased to about
.15% or 1500 parts per million instead of the.035. .04%
found in urban areas. Higher
concentrations of C02 can increase the growth rate up to
300%. Usually though, growers
report increases ofunder 100%. Either way, growth rate is
increased significantly. when
plants grow faster, it takes less time to yield a bigger
crop. Once C02 enrichment is
added to the grow space, light will most likely be the
limiting factor. The most practical
method that a closet farmer has to enrich the garden with
gas is a C02 tank with a
regulator. The regulators are sold by all of the high-tech
garden supply companies. These
devices control the number of cubic feet of gas released to
the garden. C02 gas refills
are available from companies listed under the Bottled Gas or
Industrial Gas Sections of
the Yellow Pages. The largest tanks hold 50 pounds of gas,
but they weigh 170 pounds
filled. A 20 pound tank is much smaller and weighs about 50
pounds filled. At room
temperature there are 8.7 cubic feet in a pound of gas.
Refills are inexpensive. C02
enrichment reduces ventilation requirements considerably for
several reasons. First, the
C02 in the air is being replerished and the plants function
more efficiently at a higher
temperature when C02 is at high levels. Rather than trying
to draw in C02 from the
surrounding atmosphere, the aim is now to stop the gas from
dispersing into it. Growers
figure out how much gas to use by finding the number of
cubic feet (ft3) there are in the
grow space (length x Width x Height). For instance, a closet
6 feet long 2.5 feet wide and
8.5 feet high contains 127.5 ft3 Then they multiply that
number by .0015. In this case the
figures look like this: 127.5 x .0015=.191 ft3 One grower
had a closet 3 feet by 3 feet by
10 feet He figured that its area was 90 ft3 To find the
amount of gas to inject he
multiplied 90 x .0015= .135 ft3 For each one hundred ft3 of
space about .15 ft3 of gas is
required. Small unventilated closet areas are sometimes set
up with a constant flow of C02
enrichment when the lights are on. Well designed ventilated
rooms are re- enriched every
time the ventilation stops. Unventilated rooms need a full
replenishment of C02 every one
to two hours. A room 6 x 3 x 9=162 ft3. The lights are on
continuously and the air is
enriched with a steady flow of.25 ft3 of C02 per hour. Six
feet of gas is used per day. A
20 lb. tank holds 20 x 8.7=174 ft3 + 6 = 29 days of use per
refill. Growers often
ventilate the hot air out of the space to disperse heat.
They found that it does not do
much for the plants to run the C02 enrichment system and the
ventilation system at the
same time, since the gas is drawn out Instead, the C02 unit
goes on after the ventilation
system has stopped and quickly re-innoculates the area with
C02. Some high-tech garden
companies sell devices designed to regulate the systems
automatically. C02 is heavier than
air, and when it comes out of the tank it is being
depressurized, which makes it cold.
Subsequently, the gas sinks as it enters the space. In
gardens with little internal
ventilation the tubing is usually suspended just over the
tops of plants. In large spaces
the gas is sometimes dispersed using laser drilled
Irrigation tubing or released in front
of the internal fans. Exhaust gas emitted from a stove or
water heater is suitable for the
garden. A garden in a room with a water heater will be
enriched every time the burners
light. Of course, anytime a person works with natural or LP
gas or with fire, they must be
very careful. Step By Step Plants do best in indoor gardens
when they are supplied with
C02 Growers usually choose: 1. An open door or curtain is
often the best solution for
small spaces which have a large surface-to-air ratio. 2.
External ventilation to blow out
the used air and draw in new air. This is usually adequate
for small rooms. 3. A C02
enrichment system. This consists of a tank and
regulator-flow meter and either a timer or
other automatic valve. This increases the growth rate of the
plants phenomonally. 4. A
water heater or gas stove may supplement the garden with
CO2. Along with light and
humidity, temperature is one of the most important factors
in the growth of marijuana.
This chapter provides experimentally verified day and night
temperatures that work best
for marijuana plants, including both atmospheric and growth
solution temperatures.
Temperature has a tremendous effect on plant growth through
its influence on the
biophysical and biochemical reactions of metabolism. In
general, the optimal temperature
is that of the plant's natural environment. Although an
increase in temperature usually
brings about an increase in the reaction rates of
metabolism, temperatures above 45
degrees centigrade cause enzyme inactivity, and above 55~60
degrees centigrade protein
denaturation occurs, resulting in injury or death. All
varieties of cannabis originate in
temperate or tropical climates. Plants from temperate
regions have an optimal daytime
temperature of about 25-30 degrees centigrade. Tropical
plants have the same optimal
daytime temperature, but they cannot withstand the extreme
temperatures experienced by
temperate-climate plants. Tropical temperatures vary only
slightly during the growing
season. Plant physiologists have also discovered that
optimal nighttime temperatures
differ from those that are optimal during the day. This
phenomenon, known as
thermoperiodicity, results from the fact that organic
substances, produced through
photosynthesis, move faster at lower temperatures (because
sugars are more concentrated at
lower temperatures), while cell division and enlargement
occur at higher temperatures. It
has been found that a photoperiod temperature of 30 degrees
centigrade and a night time
temperature of 22.2 degrees centigrade, maintained
throughout the vegetative and
reproductive phases, work very well for both temperate and
tropical plants. A temperature
variation of a few degrees in either direction will not
produce any significant effects.
Few studies have been conducted on the optimal temperatures
for proper root growth.
Generally, the best results have been obtained when the root
temperature is a few degrees
below the air temperature. It has been found that a solution
temperature of 25 degrees
centigrade stimulates vigorous root growth. However, more
research is needed in this area.
How do marijuana plants actually grow? This chapter explains
the growth process in detail,
and tells how growers select, store, and germinate marijuana
seeds; how they trim the
plant for befter growth; how they determine the sex of
plants. It covers techniques for
influencing resin production; methods of curing; and a
step-by-step procedure for
extracting and refining THC from the leaves that would
otherwise be useless. Life Cycle As
with all seed plants, the life cycle of cannabis evolved
through the process of
alternation of generations. Alternation of generations
involves the alternating of
non-sexual (sporophytic - marijuana plant) and sexual
(gametophytic - pollen grain, ovule)
phases of the same organism. The seed contains the embryonic
marijuana plant sporophyte.
After germination the seedling marijuana sporophyte consists
of the first bud and its
stem, the epicotyl. Next, continuing downward, are the first
leaves, the cotyledons. Below
the cotyledons is the first stem unit, the hypocotyl, and
the first root, the radicle .
The marijuana plant's sporophytic phase represents growth
from the embryo to reproduction.
The production of flowers begins sporogenesis and marks the
maturation of the plant.
During sporogenesis, the microspore mother cells undergo
meiosis [a special type of
nuclear division in which the diploid chromosome number (2n)
is divided in half (haploid,
In), and genetic segregation occurs). This is followed by
mitosis (the original chromosome
number is preserved by replication, and segregation of genes
does not usually occur),
giving rise to the pollen grain (sperm), which is the male
gametophyte (plant). The
megaspore mother cells follow the same process, only they
give rise to the ovule (egg),
which is the female gametophyte (plant) and eventually
becomes the seed. The life cycle
has now moved into the sexual phase of growth. Following
pollination, the pollen tube
attaches itself to the ovule (egg); the pollen tube bursts,
releasing its sperm into the
cytoplasm of the female gametophyte (plant). When the sperm
and egg flow together,
fertilization has occurred and the zygote - an individual
developing from the union of two
gametes (sperm and egg) - is produced. The zygote undergoes
a series of nuclear cell
divisions, forming a mass of cells. This mass of cells is
the young sporophyte (plant) of
the next generation. The young marijuana plant is nourished
by food that was transported
and stored by the parent plant. The embryo then becomes
dormant after digesting most of
the food, which is usually absorbed into the cotyledons. The
embryonic sporophyte will
remain in this dormant stage until the seed comes in contact
with a suitable environment
and eventually germinates. Germination is merely the
emergence of the embryonic plant into
the external environment; thus the life cycle is initiated
again. Any type of marijuana
seed yields good results with the water culture method.
However, as mentioned earlier,
there are tropical and temperate varieties of cannabis. A
pure tropical strain from the
state of Oaxaca, in southern Mexico, produces a good
variety, well-suited to the water
culture method. Oaxaca has a tropical wet-and-dry climate.
Seventy-five percent of the
rain falls between May and September. Occasional days of
continuous rain occur in July and
August, which is why the Oaxaca highlands receive some of
the highest amounts of rain
recorded in Mexico. This is followed by a prolonged dry
season from October to May; these
are the low-photoperiod months required for flowering. This
wet-and-dry climate
contributes to the quality of the plant (which will be
discussed along with reproductive
growth). The soil of the Oaxacan highlands is very fertile,
with optimal mineral
concentrations. As noted, Oaxaca is in the tropics, but its
altitude keeps daytime
temperatures in the upper 70s to mid80s, with night
temperatures averaging between the
mid-70s and the lower 70s throughout the year. Rain may cool
the mornings, but by
mid-afternoon the temperature returns to the average.
Because of the mineral content of
the soil, the high moisture content of both soil and air,
and the average temperatures,
Oaxaca produces a very high-quality marijuana, which is
ideal for controlled environmental
growth with the water culture method. SEEDS Seeds are best
stored at low temperatures and
low concentrations of oxygen. This keeps them viable longer
by slowing down the rate of
respiration. Ninety percent germination is easily obtained
with relatively fresh seed.
Seeds older than three to four years decline to less than
twenty percent germination in
general, and are therefore discarded. An airtight mason jar,
kept in a refrigerator set at
45 degrees F, works fine for storage purposes. The
environmental factors influencing
germination are temperature, nutrients, atmosphere, and
light. Seeds can withstand a wide
range of temperatures when dry, but only a very narrow range
after germination. The
optimal temperature for germination depends heavily on the
variety of plant used. The only
way to determine optimal temperatures for germination is to
experiment with various
temperature ranges and calculate the percentage of
germination in each. When these
experiments are performed, it is essential to keep the
nutrients, atmosphere, and light
the same for each temperature range. High mineral
concentration in contact with the seed
may produce an osmotic effect that causes water to move from
the seed into the nutrient
solution, thereby preventing the seed from obtaining enough
water. Again, if the radicle
does not protrude from the seed coat, the tissues will
dehydrate and die. For germination,
a mixture of nutrients should be one-half the dose given in
the directions for hydroponic
use. The germinating embryos must be kept in a location that
allows free gaseous exchange
with the atmosphere. Oxygen is necessary for cell division
to occur in the germinating
embryo. Marijuana seeds can germinate either in light or in
darkness. However, it has been
shown that although the radicle may emerge from the seed
coat in total darkness, this
occurs only in 15 to 20 percent of the germinating
population, and further development of
the embryo is still impossible without light. (Moreover,
fungal growth rapidly overtakes
the moist, warm, dark embryo tissues.) In contrast, when the
germinating population is
exposed to photoperiods of 18 hours per day, 85 to 95
percent of the embryos germinate and
develop. The best germinating medium is coarse vermiculite,
which allows the maximum
amount of oxygen to be drawn into the roots while nutrient
solution is being added.
Vermiculite is also easy to remove from the seedling roots
before placing them in the
growth tanks. The vermiculite is placed in a suitable
container (e.g., a pie pan or cake
pan), filling it to about 1/2" from the top. The
nutrient solution is then mixed as
described above, and used to gently fill the container
around the sides until the solution
can be seen just above the surface of the vermiculite. It is
important that the hilum (a
small pore at the end of the seed which is relatively
permeable to water) be positioned at
the surface of the vermiculite, with the raphe (a ridge or
seam along the outside of the
seed coat) facing downward (see Figure 4). This ensures
maximum contact of the hilum with
the nutrient solution and keeps the radicle extending down
and not along the surface,
where it would become photosynthetic and would be inhibited,
or even prevented, from
germinating further. The first phase of germination is the
absorption of water. Dormant
seeds contain about 20 percent water; actively growing
seeds, 95 percent water. Hydration
increases enzymatic activity, using stored food from the
parent plant. The embryo
eventually increases in size and cracks open the seed coat.
The first part to emerge is
the radicle. As the radicle pushes downward, the hypocotyl
extends upward and becomes
photosynthetic. The seed coat continues to cover the
cotyledons for a short time, until
the cotyledons have digested all of the stored food. They
then enlarge, shedding the seed
coat. After the cotyledons have emerged and the seedling is
growing on its own, the
nutrient solution is increased to the full dose recommended
for hydroponic use in the
directions. The plants must be kept wet! At this point,
solution is gently added around
the plants to allow oxygen to be drawn into the medium. When
the plants have reached a
height of four to six inches, they are ready to be
transplanted to the growth tanks. As
mentioned earlier, vegetative growth of the sporophyte
occurs during the period between
the emergence of the plant from seed to the onset of
flowering. Development of the plant
during this stage of the life cycle depends on cell
division, cell enlargement, and cell
differentiation. Plant growth substances, termed
phytohormones, are responsible for
regulating such aspects of vegetative growth. There are
three basic plant growth
substances: (1) auxins, (2) gibberillins, and (3)
cytokinins. The response of cannabis to
plant growth substances in general has not been widely
documented; however, it is well
established that auxins inhibit branching. In seed plants,
branches originate from a
dome-shaped mass of cells in the axils
("armpits") of leaves. The original
structures are known as axillary or lateral buds. When the
bud develops into a shoot, the
apical meristem (actively growing tip) is slowly organized,
usually duplicating the growth
pattern found in the parent shoot tip. Auxins are produced
in the apical meristem and then
transported down the stem. If the source of auxin is removed
by pruning the apical
meristem, the branches are released from the auxin's
inhibiting effects and undergo rapid
development. Removal of the apical meristem is a method used
by many horticulturists to
encourage the increased production of floral buds. This is
particularly true, of course,
in the case of marijuana. When the apical meristem is
removed, the development of two
axillary buds in the leaf axils directly below is
stimulated. Now the plant is developing
two branches where it would have produced one - and each
shoot is capable of producing
floral buds. Another advantage of removing the apical
meristem is the promotion of
horizontal growth, which allows the plant to remain shorter.
This is a critical factor,
especially in view of the low ceiling heights of some
marijuana growth chambers (such as
those in basement locations). When the apical meristem is
removed, the size and number of
foliage leaves are reduced. However, even though this
occurs, successful growers remove
the foliage leaves (except for the two directly below the
apical meristem) from the branch
at the time when the apical meristem of the branch is
removed. Although this method may
seem odd at first, it has been well demonstrated that when
foliage leaves reach full
expansion there is a rapid decline in chlorophyll
concentration and a decrease in the rate
of photosynthesis. Through the removal of the less efficient
foliage leaves, young leaves
are allowed to expand quickly, increasing chlorophyll
production and the rate of
photosynthesis. The foliage leaves are not discarded. They
are collected and stored in an
airtight container until the end of the plant's life cycle.
(A method for extraction of
their THC will be given in a later section.) Since a great
deal of time and effort has
gone into the production of each plant, growers utilize all
parts of any value. The leaves
and apical meristems are removed once a week for five weeks
after the plants have been
placed in the growth tanks. It has been mentioned in the
literature that pruning the
vegetative apical meristems before flowering will cause the
plant to flower late or not to
flower at all. (It was suggested that if the meristematic
tissues responsible for sensing
change were removed, the plant would no longer be able to
determine when it was time to
flower.) However, it has been established that the
photoperiodic response is perceived by
the leaves and not by the apical meristem. Further, it is a
well-documented view that the
flower and the vegetative shoots are not related structures,
and that their meristems are
basically different. Floral induction is not a sudden
change, but a series of stages. It
has been found that when apical meristems are removed one
week prior to the floral
induction photoperiod, flowering is neither delayed nor
prevented. Again, growers prune
the apical meristems and the foliage leaves once a week,
from the end of the first week to
the beginning of the fifth week of growth. At the beginning
of the sixth week, the floral
induction photoperiod has started, and all pruning of the
leaves and apical meristems is
stopped for the duration of flowering. When the
photoperiodic change is perceived by the
leaves, the florigen (the flowering stimulus) is produced in
the leaves and transported to
the apical meristems where floral formation is initiated.
The floral apical meristems
replace the vegetative ones directly, usually by the
development of inflorescence (an axis
bearing flowers, or a flower cluster). With both sexes, the
first evidence of flowering is
seen in the formation of primordia (tiny shoots in the
earliest stage of development) at a
node (point of attachment of a leaf to a stem; also a branch
emergence) of the principal
stem adjacent to the axillary bud itself. Primordia are
initially undifferentiated, but
later males show their rounded form, with females showing
enlargement of the single
pointed bract (modified leaf - see Figure 5). Cannabis is
considered a dioecious plant,
meaning that the male and female flowers develop on separate
plants. Monoecism (in which
male and female flowers develop on the same plant) does
occur, but can be controlled by
changing the length of the photoperiod. (See the section on
photoperiodism in Chapter 1.)
This is important for pollination techniques (see Clarke).
The most easily detected change
from the vegetative to the reproductive phase in cannabis is
the sudden increase in the
elongation of the internodes (the region of the stem between
two nodes). This is
particularly true in male plants. Furthermore, the males are
more copiously branched, and
show speedier reduction of leaves into the form of floral
bracts, with a reduction in
relative chlorophyll content. Female plants, on the other
hand, appear shorter and leafier
than the males. All of these characteristics can be helpful
in determining the sex of a
plant; however, they are very general characteristics, and
should by no means be
considered absolute indicators of gender. Indeed, both male
and female plants grown in an
environmental growth chamber, and pruned on a weekly basis,
appear short and bushy, so sex
determination cannot be made until the early floral stages.
Furthermore, physiological
tests (such as respiratory rate, sap pH, and pigment
content) have failed to reveal any
differences in physiological characteristics between the two
sexes. As noted in the
description of female flowers, glandular trichomes (hairs)
are associated with THC
production. They contain very large amounts of resin, and
the volume may be several times
that of the excretory cells responsible for their
production. Glandular trichomes are more
abundant during the peak floral stage on the undersides of
the leaves, and in the floral
bracts and petioles. More are produced on female plants than
on males, though they are
quite numerous on the males as well. In fact, studies have
shown that male plants possess
as many cannabinoids per unit of fresh weight as do female
plants with the same amount of
flowering. However, after the male plant has shed its
pollen, the flowers wither and die,
which stops resin production, while the maturing female
flowers continue to develop more
copious amounts of resin-containing trichomes. Because of
the high resin content of the
male plants, their foliage leaves should be stripped and
stored with the others for
extraction of THC if the plants are not to be used for
breeding purposes. The exact
function of the glandular trichomes and of the resins they
contain is not well understood.
One possibility is that the increased amount of resin
produced during the peak floral
stage of the female flowers functions as protective
insulation of the delicate ovaries,
and the subsequent seeds, against desiccation (drying) and
insect predation. It has been
demonstrated, by controlling the relative humidity and the
amount of water available to
the roots for absorption, that there is a direct correlation
between desiccation and the
influence on THC production. After the female flowers have
reached the two-week phase of
development, the relative humidity of the growth chamber is
dropped from the previously
maintained level of 60-70 percent to zero, and the amount of
solution in the growth tanks
is reduced to half the amount previously available for
absorption. The plants overall
respond favorably by producing extremely plentiful,
resin-filled trichomes. Also, this
technique will in no way inhibit or prevent continued
development of the female flowers.
This does lend support to the notion that the glandular
trichomes and their resins are
related to an environmental response of desiccation. The
time of harvesting depends upon
the variety of the plant used. Each type has a different
rate of maturation. However,
there is one general guideline that applies to all varieties
of cannabis. Growers take
accurate daily growth records of the length of the flowers.
When elongation slows and
stops, the flowers have usually reached maturity and
glandular trichome production is at
its peak. This is the time to remove the flowers from the
plant. They are cut from the
branch or stem below the two leaf nodes located directly
beneath the flower. The nodes
then provide a mechanism for hanging the flower during the
curing process. Curing The
purpose of the curing process is to allow the plant tissues
to break down metabolically to
yield the texture and aroma desired for smoking, which are
strictly a matter of personal
preference. There are many methods of curing; the method
discussed here works well. String
or twine is attached to two points to form a
"clothesline." On the string, the
flower is hung upside down by the notch in the nodes.
Hanging the flower upside down
allows the leaves and floral bracts to surround the delicate
resin-covered calyx, and
protects it from handling damage. Curing is best done in low
light or in darkness, and at
humidity levels between 40 percent and 60 percent. However,
fungi and bacteria thrive in
this type of environment, and care must be taken to ensure
that contamination of the
flowers does not occur. If the area is disinfected
thoroughly and a very slight flow of
air maintained, no problems should arise. This method causes
chlorophyll to become
inactive (because of the paucity or absence of light), and
the humidity prevents rapid
drying of the floral tissues, thereby allowing chlorophyll
and other plant metabolites to
be broken down slowly. Clarke suggests that if curing of the
tissues is done quickly,
insufficient gaseous exchange with the intercellular tissues
occurs; this causes the
"greenness" to be locked in, and no amount
of further curing will remove it.
This has generally been found to be true. The more slowly
the tissues can be cured, the
milder the taste. A moister texture also results. Since so
much time, labor, and cost has
gone into the production of each plant, growers do not
overlook utilization of the
"shake" or leaves. Extraction involves the
process of removing the essential
oil, THC, from the leaves remaining on the plant and those
removed during pruning. This is
accomplished through the use of a solvent in which the oil
will dissolve, which is later
separated from the plant material by passing it through an
appropriate filter. The best
solvent found to date is chloroform. It is non-flammable,
which makes it safer to handle
than ethanol. Further, it has a low boiling point (61
degrees C), and a residue after
evaporation of .0005 percent. The low residue percentage
means that virtually no trace
solvent remains to contaminate the oil and cause an
aftertaste, which is usually a problem
encountered with ethanol unless time-consuming distillation
processes are used. Another
important concern is that chlorophyll is relatively
insoluble in chloroform, eliminating
the heavy "green" taste that always
results from ethanol extractions. To
initiate the extraction process, the leaves must be dried
thoroughly. This can be done by
placing them on fairly absorbent paper, such as newsprint,
in a good sunny spot near a
window. (Fresh newsprint paper may be obtained in most art
supply stores. The lead content
of ordinary newspapers makes them unsuitable for this
purpose.) The leaves are then turned
over every few days to ensure complete drying. When they are
sufficiently dry, the leaves
should be brittle and crumble easily between the fingers.
When the leaves have completely
dried, they are placed in a blender and ground to a fine
powder. Studies have shown that
to achieve 90 percent extraction of the oil, the plant
material must be powdered. This is
because nearly as much oil is contained in non-glandular
internal tissues as is produced
by the glandular trichomes. Next, a filter (the type used
for automatic coffee makers) is
placed over a clean Pyrex beaker or Corning Ware dish. The
plant material is piled about
halfway to the top of the filter, and the rest of the
material saved (if necessary) in an
airtight plastic container. At this point, approximately 200
milliliters of chloroform are
poured into the blender and sloshed around on the sides.
This rinses out any oil remaining
in the blender. Chloroform is poured from the blender over
the plant material until it
reaches the top of the filter (adding more chloroform if
needed). When the chloroform has
completely filtered into the beaker or dish, this process is
then repeated by adding
chloroform until it reaches the top of the filter. Two
extractions of the same plant
material are usually sufficient to remove all of its oil. At
this point, the plant
material is discarded; the same procedure is repeated until
the beaker or dish becomes
full of solvent. Now the beaker or dish is placed on an
electric stove or hot plate and
heated slowly to a very low boil. When chloroform is being
evaporated, the area must be
completely ventilated! In the early days of medicine,
chloroform was used as an anesthetic
until harmful side effects (such as liver damage) were
discovered, so it is clear that
extreme care must be used when evaporating this solvent.
After the solvent has been
removed, the same procedure is repeated until all of the
plant material has been treated.
The oil is collected and stored in a pipette (small glass
tube). These can be obtained at
any scientific supply company and are inexpensive. The oil
is drawn into the tube (this
may be easier if the oil is first heated a bit), and the
tube capped at both ends. The
storage procedure is the same as that outlined for floral
tops. After the flowers have
been cured to the desired extent, they are stored to prevent
further drying and breakdown
of the floral tissues. This can be accomplished by one of
two methods. The first is to
store the flowers in a mason jar or similar container, which
can be sealed and kept
airtight. The jar or container is maintained in an
environment of low light and humidity.
Once the oxygen in the container has been used for the
further metabolic breakdown of
tissues, drying will cease. Another alternative is to use a
small vacuum food processing
unit. This is probably the most efficient way to store the
flowers. By placing a vacuum
pump on the container (again an airtight one), with the
flowers inside the container, and
sealing tightly, further curing is eliminated instantly by
removing all oxygen with the
vacuum. The advantage of this method is that it gives plant
tissues an essentially
unlimited shelf life: they will last for years. Growers
generally check with sellers of
food processors and laboratory equipment for systems that
can handle this particular
method. As with the first method, the final product is
stored in low light and humidity.
PLANTING Successful growers plant marijuana seeds ahout a
half inch deep and then cover
them. Seeds placed in substrates are pushed into the
material so that they are totally
surrounded Once the seeds are planted, the medium is watered
again to help the seeds
settle in place. The direction that the seed faces is not
important. Using gravity as a
means of sensing proper direction, the seed will direct
roots downward and the stem upward
Marijuana need not be planted in its final container to
start Even a plant which is
destined to be a giant can be started in a 2 inch pot or
block The advantage to starting
small is that the plants do not take up unneeded room.
However, plants must be given more
room soon alter germination or they will become rootbound,
which stunts the plants.
Seedlings are trans planted using the same techniques
described under cuttings.
Germination begins when moisture seeps through the seed coat
and signals the seed to start
growing Heat regulates the rate ofgermination and growth
until the seedling reaches light.
Water The planting medium is kept moist until germination is
complete. if the surface of
the medium tends to dry out, plastic wrap is placed over it
to retain moisture. Seedlings
have tender root systems which are easily damaged when the
medium dries out so the medium
is kept moist at all times. Heat Marijuana germinates
rapidly when the planting medium is
kept at an even temperature. Room temperature, about 70
degrees, is best. when the medium
is cool, germination slows and the seeds may be attacked by
fungi or other organisms. With
high temperatures, seedlings grow thin and spindly,
especially under low light conditions.
This occurs because their growth rate is sped up by the
heat, but the seedlings are not
photo-synthesizing enough sugar for use as building material
light Once the seedling
breaks ground and comes in contact with light, it starts to
photosynthesize, thus
producing itsown food for growtll When the light is dim, the
plant stretches to reach it.
In the wild the seedling is in competition with other plants
which may be shading it. By
growing taller it may be able to reach unobstructed light.
However, a stretched seedling
is weaker than one with a shorter but thicker stem and has a
tendency to fall over.
Seedlings with ample light grow squat, thick stems.
Seedlings can be started in constant
bright light of the same intensity that is to be used for
their growth cycle. Some growers
recommend that seeds be germinated in a napkin or on a
sponge and then placed into the
growing area This method risks damage to the seedling in
many ways; the delicate plant
tissues may be darnaged by handling or moisture problems,
the seedlings are more likely to
be attacked by infections and they may be subject to delays
in growth caused by changes in
their position in relation to gravity. CUTTINGS (CLONES)
Many growers populate their
gardens with cuttings rather than seeds. Cuttings have
several advantages over seeds.
Clones. Transplanting cuttings is very easy. Cuttings which
have been rooted in a
substrate such as floral foam, Jiffy rooting cubes or
rockwool are easily placed in a
larger rooting area If the cuttings are being transferred to
another substrate, the small
block with the rooted cutting can be placed firmly on top of
the larger substrate. Growers
rub the two blocks together so that there is firm contact
between the two materials. The
roots will grow directly from the smaller block into the
larger one. Growers report that
it is also easy to transplant substrate rooted cuttings into
a soil or soil-less medium.
The cutting is not held by the leaf or stem, because the
pull of the heavy block may
injure the stem or tear the roots. Instead, the block is
held and placed in a partially
filled container. After placing the block in the container;
mix is placed around itso that
the block is totally covered The medium is tapped down
firmly enough so that it is well
packed but not tight or compacted when transplanting plants
grown in degradable containers
such as peat pots or Jiffy cubes, growers report best
results when the containers are cut
in several places. This assures an easy exit for the roots.
Cuttings growing in individual
containers are transplanted before they are root-bound
First, the rootball is knocked from
the container. To do this, growers turn the plant upside
down so that the top of the soil
is resting between the index and middle finger of one hand
with the stem of the plant
sticking through the fingers. The container is held in the
other hand and knocked against
a hard surface such as a table. The rootball is jarred loose
from the old container and
rests in the gardener's hand The rootball is placed in a
larger container partially filled
with mix Then mix is added to bring the medium to within a
half inch of the top of the
pot. when plants have a long bare stem, growers sometimes
place the plant deeply in the
container, burying part of the stem. Paper cups are
sometimes used as containers. They are
carefully opened using a utility knife or scissors.
Rootballs sticking to styrofoam cups
sometimes release if the cup is rolled tightly between two
palms before knocking if the
rootball still sticks, the cup is cut open. Once the
rootball is out it is placed in a
container partially filled with medium. More medium is added
packed firmly around the
rootball, until the top is covered Transplants sometimes
take a few days to adjust. Then
their growth spurts with renewed vigor. Step By Step 1.
Seeds are usually planted one half
inch deep and covered 2. Growers often start seeds in smalll
containers. They are
transplanted as they grow. This way small plants do not
waste unused space. 3. Seeds are
kept moist at 70 (degrees) to encourage fast germinatioft 4.
Growers transplant cuttings
easily by placing the the rootball in a partiallyfilled
container. Then planting medium is
added until the ball is completely covered CUTTINGS AND
CLONES Nearly everyone has taken a
cutting from a houseplant and placed it in water. Within a
short time roots grew and the
new plant was ready to he placed in a container with medium.
The new plant had the same
genetic mak-up of its clone mother. The new plant's growth,
flowers, and reactions to
en"ironment were exactly the same as the plant from
which it was taken The genetic
make-up, and therefore the characteristics of a plant
started from seed cannot he
determined until the plant is grown Although the lineage of
the plant may provide a fair
amount of information, there is no way of pre- determining
its exact qualities. There are
literally billions of possible combinations of genes that
the two parents can supply. No
two plants from seed are likely to he identical. There are
many advantages to growing
genetically identical plants. Here are some which growers
have brought to my attention: 1.
The plants have uniform growth characteristics so the garden
is easier to maintain Each
plant grows to the same size, has approximately the same
yield and matures at the same
time as its sisters. Starting from seeds, plants of the same
variety exhibit subtle
differences in growth patterns. 2. Buds from clone sisters
will he of the same potency and
taste the same. 3. There will he no males in the garden
Since all clones from a single
"clone-mother" have the same genetic
make-up, clones from a female plant can he
only female. Usually about halfof the plants from seeds turn
out to he male. Using clones
saves valuable garden space which would have heen used to
grow males. 4. Clones seem to
exhibit shorter internode length (distance hetween the
leaves) which means that the garden
has shorter, stouter plants. 5. The exact genetic make-up of
a particular plant is easily
preserveci This means that the characteristics of a
super-plant or other novel specimen
can he continued. There are also disadvantages to growing
clones: 1. All of the plants
from a single clone mother yield the same product. There is
no variation Gardeners growing
for personal consumption often wish to grow several
different varieties. 2. There is no
genetic progression Since no breeding is taking place, the
genetic line remains static
There are no surprises and no new finds. Using clones, there
is no way ofgenetically
adapting a line to aparticular environment. HOW CLONES ARE
MADE Cuttings are taken from
soft green tissue hecause the drier, woody sections of the
plant do not root as easily.
Sections taken are 2-5 inches long with several sets of
leaves. The cut is made with a
very sharp blade which makes a clean, straight cut, rather
than a scissor which pinches
and injures the tissue. As the cuttings are made they are
placed in a bowl filled with
lukewarm water to prevent them from drying out Once all the
cuttings are taken, they are
trimmed of their lower leaves, leaving only one or two sets
plus the growing tip. This
helps to prevent the cutting from heing water stressed. if
the leaves were left on the
cutting they would create water demands that the stem end,
with a limited draw, cannot
meet. Any large fan leaves are also removed for the same
reason Next, the rooting solution
is prepared. liquid type rooting compounds are the best to
use hecause the active
ingredients are in solution and are guaranteed to come in
contact with the stem. Powders
are often scraped off as the cutting is set in place, and
drop offwhen placed in water.
Some popular rooting solutions which work well are Olivia's,
Klone Concentrate,
Hormex"' and Wood' s. The solution is used as
directed for woody plants. The trimmed
cuttings are placed either in water or a rooting medium such
as vermiculite, rockwool or
floral foam which has heen watered with one quarter strength
flowering formula fertilizer
solution At least 3/4 inch of stem is inserted in the
rooting medium which is be patted
down to make sure that the stem is in direct contact with it
The cuttings growers make are
placed in an area of high humidity to limit water stress.
Growers often construct a
"mini-greenhouse" using plastic wrap
placed over the rooting chamber. Some trays
come with clear plastic covers to retain moisture. The cover
is removed when the plants
develop roots. A fine mist spray helps relieve water stress.
The clones respond best to a
moderate rather than a bright light Some gardeners light the
clone garden using 2 tubes
for an area 4 x 2 feet, 10 watts per square foot. Clones
being rooted in water do best
when the water is changed frequently and aerated using a
small pump and an aquarium
bubbler. Rooting blocks or medium must be kept well
saturated The temperature of the
medium affects the rooting time of the clones. Cuttings root
fastest when the temperature
is kept in the low to mid 70's. At lower temperatures the
cuttings take longer to root and
are more likely to suffer from infections. Growers report
the easiest way to keep the
cuttings warm is to use a heating cable or heating mat made
especially for germinating and
rooting plants. These are available at most plant nurseries
and are very inexpensive.
Given good conditions, cuttings usually root in one to two
weeks. Some varieties are
easier to root than others. For instance Big Bud, is
notoriously difficult to root Skunk
and Northern lights are much easier to clone. Rockwool
Growing Medium Rockwool is the
neatest invenfion since the sun! It is an inert, sterile,
porous, non-degradable growing
medium that provides firm root Support. Like all soilless
mediums, rockwool acts as a
temporary reservoir for nutrients. This affords the grower a
tremendous amount of confrol
over plant growth through nutrient uptake. This
revolutionary new growing medium consists
of thin strand- like fibers made primarily from limestone,
granite or almost any kind of
rock. Rockwool has the appearance of lent collected by
cloths dryer. It is unique and does
not resemble any other growing media. Rockwool has been used
for many years as home and
industrial insulation. In fact the walls in your home may
surround you with this product.
The rockwool used for insulation is very similar to the
horticultural grade except for one
thing; the industrial grade used for insulation is treated
with a fire retarding substance
that will kill plants. Growers all over the world will be
using rockwool as soon as they
find out about it. Definite advantages are reaped when
growing in this soilless substrate.
It is economical, consistent and easy to control. Now the
best part: rockwool is very
fibrous in structure and will hold about 20 percent air even
when it is completely
saturated. If this stuff is so good, why haven't I heard of
it yet? Rockwool has recently
been introduced into the U.S. in 1985. The word travels
slowly and the American
horticultural community has been slow to adapt. Most of them
have not even heard of
rockwool yet. Rockwool has been used in European greenhouses
for over 15 years. Rockwool
was first discovered in Denmark in 1969. Growers began using
rockwool as a way around the
ban on soil-grown nursery stock imposed by some of the
European community. Today, an
estimated 50 percent of all western European greenhouse
vegetables are grown exclusively
in rockwool. Other mediums like peat and soils are becoming
more expensive to produce and
can easily vary in quality. This coupled with high cost of
sterilization prompted European
growers to explore new alternatives. European growers
switched to rockwool because it is
inexpensive and easy to control but the important fact is
that they not only changed, they
continued to use it. More acreage is coming under production
using rockwool daily. In fact
growers at The Seed Bank in Holland swear by rockwool.
Rockwool is produced from rock
alone or a combination of rock, limestone and coke. The
rigid components are melted at
temperatures exceeding 2,500 F. This molten solution is
poured over a spinning cylinder,
very similar to the way cotton candy is made with liquified
sugar. As the molten solution
flys off the cylinder, it elongates and cools to form
fibers. These fibers could be
likened to cotton candy fibers. The product of these fibers,
rockwool, is then pressed
into blocks, sheets, cubes or granulated. The blocks are
rigid and easy to handle. They
may be cut into just about any size desirable. Granulated
rockwool is easily placed into
growing containers or used like vermiculite or perlite as a
soil amendment. The heat makes
the rock wool sterile and I do not know of any bugs or
microorganisms that are able to
live at these temperatures. Rockwool can be used in both
recirculating and
nonrecirculation hydroponic systems. But the
non-recirculating system is much easier to
control. As explained earlier, the nutrient solution in a
recirculating system is
constantly changing. Salts soon build to toxic levels as
plants use selected nutrients
within the solution. The nutrient solution is constantly
monitored and adjusted to provide
the exact concentration of nutrients for optimum growth.
However, with an open ended
system, the excess nutrient solution drains off and is not
recovered. The plants get all
the nutrients they need and any nutrients that are not used
will simply drain off. A fresh
nutrient-rich solution is used for the next watering. Apply
enough nutrient solution to
get a 25 percent drain or leaching effect. This serves two
purposes: 1) it flushes out
excess salts from the medium and applies adequate nutrient
solution to the medium. When
used with an open ended drip system, rockwool is easily
irrigated with a nutrient solution
controlled by a timer. The usual procedure in Europe is to
apply a small amount of
fertilizer to or three times a day. Enough excess solution
is applied to obtain a 10-25
percent leeching effect every day. Do not let all of this
control fool you. Even though
rockwool will hold 10-14 times as much water as soil, it
does not provide the buffering
action available in soil. The pH of rockwool is about 7.8.
An acidic fertilizer solution
(about 5.5 on the pH scale) is required to maintain the
actual solution at a pH of about
6.5 or lower. Errors made in the nutrient solution mix or
with pH level, will be
magnified. & careful to monitor both the pH and
nutrient level with a scrutinous eye.
There are some tricks to handling rockwool. Dry rockwool can
be abrasive and act as an
irritant to the skin. When handling dry Rockwool, use gloves
and goggles. Once the
rockwool is thoroughly wet, it is easy and safe to work
with; it creates no dust and is
not irritation to the skin. Compaction is not a problem.
Keep out of the reach of children
and wash clothes thoroughly after prolonged use around
rockwool as a safety precaution.
Rockwool stays so wet that algae grows on the surface. While
this green slimy algae is
unsightly, it does not compete with plants for nutrition,
however harmless fungus gnats
could take up residence. Abate this algae by covering the
rockwool with plastic.
Horticultural rockwool is available from an ever increasing
number of indoor garden
stores.