Cannabis is dioesceous has both male and female plants. Un-pollinated female flower tops carry the highest levels of mind-bending THC. However, the natural ratio of female to male seeds is half and half. Increasing the number of female plants increases the amount of marijuana, a good thing!
Feminized seeds are available from Dutch Passion that pioneered the
technique and other seed companies. Feminized grow virtually all
female plants and are more expensive. Other companies, such as
Paradise Seeds, offer a baker’s dozen of non-feminized seeds.
You can use a few simple techniques to increase the number of female
plants grown from “normal” seed to 80-90 percent. The more you
work with these techniques, the more consistent the high ratio of
female to male plants will become.
Environmental factors start influencing sex the instant seedlings have
three pairs of true leaves (not counting cotyledons), at about 6 weeks
of age. The environment continues to influence cannabis sex
determination until a few weeks before flowering. At first,
specific growing medium moisture and nutrient levels, temperatures,
humidity, etc affect sex determination. As seedlings grow into
vegetative plants, internal functions and chemistry change.
Plants require different temperature, humidity, light, nutrient and
growing medium moisture levels to optimize growth, prevent stress and
culture more female plants.
Environmental factors that influence sex determination of cannabis from
approximately 6 weeks of age until 10-12 weeks of growth 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.
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.
Three to four weeks after plants enter the vegetative growth stage,
stress is the main factor that influences sex. Any environmental
stress makes more plants turn into males when growing from seed.
Preventing stress is the key to preventing males and possible
hermaphrodites, plants with both make and female flowers.
The critical time when things should be perfect is the 3rd to 4th week
of vegetative growth. Eliminate all stress – pests, disease,
drought, fertilizer, etc. – and increase the number of female
plants. some plants hermed because of problems that occurred
around this period of the plants development.
Give plants equal parts nitrogen, potassium and phosphorus to promote more female plants.
Temperatures of 65-68 produce more females. Drop the temperature
to 55 degrees F. or below will result in a higher percentage of males.
Keep growing medium well aerated and moist. Stress and more males
are created when plants dry out. Soggy soil from over-watering
also causes stress and yields more males.
Keep humidity around 70 percent to produce more female plants.
Use a metal halide lamp that contains a bluer spectrum to increase
female numbers. The reddish-yellow spectrum of a HP sodium lamp
causes more males. A 18-24-hour light period has no affect on sex
now. But more hours of light could cause temperatures to climb
Now, after all this advice, sometimes you get a pack of seeds that has
all males. If this happens, call the seed company and ask for a
G13 – According to legend, “G” stands for “Government” and the 13th
letter of the alphabet is “M” for marijuana. This strain was
purportedly pinched from the US government Marijuana Research Facility
in Mississippi. I have searched high and low and found no
credible source to substantiate any of this BS.
A very strong indica, G13 is most often crossed with other varieties to
augment its low yield and fair taste. The genetics are available
from ????. This plant is making a comeback. Who uses it in
Taste – bland, Hashy, spicy fruity smoke
High – on hit wonder, trance-like, body stone
Potency – extreme, above 25 percent
Genotype – pure indica, mainly used in crosses
Culture – easy to grow and clone
Odor – low to medium fragrance
Habit – quite short and squat
Yield – fair to moderate
Disease/pest resistance – can be prone to bud mold
Indoors – 55-60 days
Outdoors – Mid October to early November
Ease to manicure – Easy, fast
Water hash quality/quantity from trim – great but medium volume