Grow More Female Plants
from Seed
Environmental factors start influencing sex
the moment the seedling has three pairs of
true leaves (not counting cotyledons).
Environmental factors that influence sex
determination of cannabis include but are
not limited to:
Increasing the level of nitrogen makes
more female plants. Lower the nitrogen level
to create more male plants. Increase the
level of potassium to increase male tendencies;
lowering the potassium level encourages
female plants. A higher nitrogen level
and a lower potassium level for the first two
weeks increases females.
Low temperatures increase the number of
female plants. Warm temperatures make
more male plants.
High humidity increases the number of
female plants. Low humidity increases male
plants. 1 ' "
Low growing-medium moisture increases
males.
More blue light increases the number of
female plants. More red light increases male
tendencies.
Fewer hours of daylight (e.g. 14 hours)
increases the number of females. Longer
days (e.g. 18 hours) make more male plants.
Stress: any environmental stress tends to
yield more male plants when growing from
seed.
Henk, owner of Dutch Passion Seeds,
http://www.ciutch-passion.nl, was kind
enough to allow us to adapt this information
from his archives.
See Chapter Seventeen, "Breeding," for information
on producing feminized seeds.