Professional Marijuana Grower November-December 2018 Issue | Page 46

Cannabis seeds need constant warmth to germinate,
but they do not require light. However, once the plants
begin to produce their first set of “true leaves” they will
require an adequate light source to perform photo-
synthesis. Photosynthesis is the exchanging of gases,
oxygen for carbon dioxide, from the surrounding atmo-
sphere and is an important process in plant growth. The
peat starter-pellets with the sprouted seeds planted in
them should be placed in a standard 10” x 20” starter
tray, with drainage holes. This is a good way to make
sure your plants don’t stay too wet after a watering
and will not sit in water that may become stagnant and
low in dissolved oxygen. Roots require high levels of
dissolved oxygen from fresh water and sitting too long
in water or in a solution can cause the roots to die. The
peat starter-pellets will provide some air pruning of the
roots on their own. This natural air pruning will lead to
more abundant new roots.
grow as large as plants started from seed, but they can
be high-yielding crops when grown properly. Clones cut
from a young, fresh donor plant, or “mother” plant, are
best. Mother plants to be used as a source of clones for
next season should be started from seed in mid-autumn
when things in the outdoor garden are winding down.
Fresh mothers are recommended because as the plants
age the genetics of the clones can begin to degrade
and they may even become hermaphrodite or male.
Allow the mother plants to become bushy and in early
March harvest the clones from the lateral shoots that
The next step is to place a short, two- to three-inch tall
humidity dome on top of the tray to help retain moisture
and heat. Mount a four-bulb t5 or t8 fluorescent grow-
light fixture with 65K-rated bulbs just above the top of
the humidity dome and keep the lights on for 18 hours
each day. Make sure the fixture height is easily adjust-
able and can be raised when the plants need water
or as they grow taller. The fluorescent lights should
provide enough heat to encourage rapid growth. Ideal
temperatures will be 70-80 degrees F within the dome
with a relative humidity between 60-70 percent when
sprouting the seeds. If temperatures are too low, then
an electric heat mat can be placed underneath the tray.
During the next few weeks, after the tiny plants have
completely emerged from the seeds, the seedlings will
begin developing several sets of “true leaves.” The first
sets of leaves that appear are called the cotyledons
and will look different than the normal leaves. The sets
of leaves that come after those and look like normal
leaves are referred to as the “true leaves”. During the
first weeks the true leaves are developing, the humidity
dome should be removed for a few hours a day. Add
more hours each day until the plants are acclimated
to the environment and the dome can be permanently
removed. Seeds love high humidity, but the seedlings
do not, because it interrupts the two important life-sus-
taining processes of transpiration and respiration. After
the plants, roots and top growth begin to get crowded
it is time to transplant them into a larger container.
They should then be removed from the greenhouse, or
greenhouse style structure. Make sure the temperature
will remain above 60 degrees Fahrenheit at night.
Clones
Starting from rooted cuttings or clones is the best way
to ensure the starter plants will be female in sex and
true to the intended strain. In general, clones won’t
46 • Professional Marijuana Grower
develop between the stems and the lower branches by
cutting them at a 45-degree angle at their base. Clones
should be taken from female plants. If a grower does
not have the availability to maintain mother plants, then
clones should be obtained from locally respected sourc-
es. Make sure to verify quality genetics. Also, be sure
your clones are free of bugs, pests, and mold before
introducing them into your garden.
Immediately after cutting the clone from its mother plant,
dip the cut end into a powdered (or liquid) nitrogen-fix-
November/December 2018