Male, female, hermaphrodite; cannabis sex is complicated. Unlike animals, plants are capable of sexing one direction, the other, or both, almost on a whim. However, cannabis sex can be predicted based on the sex of the seed’s parents and the environment the seed endures during the germination stage. With a little know how, cannabis sex can nearly be chosen from a seed at will.
Cannabis seeds are sold by strain (genetic lineage), and also by sex. The sex listed may be either of the following:
-‘Regular’ which means the sexes are segregating; male or female plants can come from a seed.
-‘Feminized’ which means no segregating; each seed results in a female plant.
But this is not the end of the story. Both sexes can turn hermaphroditic, with flowers of the opposite sex growing from the plant even after its sex has already been determined, i.e. male flowers growing on a female plant, or (less commonly) female flowers growing on a male plant. In some instances, both sexes are represented equally, with an equal number of male and female flowers coming from each flowering site. A hermaphrodite in a bloom room will create a plethora of immature seeds, ruining the taste and potency of a flower.
Hermaphrodites can come from both ‘regular’ and ‘feminized’ seeds and are typically the result of environmental stress during the bloom phase. That being said, a hermaphrodite is in fact more likely to come from a ‘feminized’ seed. ‘Feminized’ seeds are created by pollinating a female plant with the pollen from a hermaphrodite’s male flower. This is because the pollen from a hermaphrodite’s male flowers only carry the genetic information for female or hermaphroditic traits. Basically, since the father of a ‘feminized’ seed is a hermaphrodite, it is more likely to become a hermaphrodite itself than a ‘regular’ seed with ‘regular’ parents.
Since ‘feminized’ seeds come with a higher probability of hermaphrodites, other methods of achieving higher numbers of females are worth looking into. Many growers claim to achieve upwards of 90% females with ‘regular’ seeds by germinating them in ideal conditions. A stable environment with high humidity, blue heavy light, high nitrogen/low potassium in the media, and a shorter photoperiod are said to increase the likelihood of germinating a female (1). This is called ‘epigenetics’, which means gene expression changes depending on the environment. If environmental conditions are favorable, it is more beneficial for the species for the seed to become female since females can make seeds themselves. Females take more energy to mature than males, but has a high probability of success in a favorable environment. In addition to that, a single male can pollinate many females so fewer males are necessary.
(1)“How to Get More Female Plant’s From Regular Seeds.” CANNA connection, 18th of June 2018, https://www.cannaconnection.com/blog/18582-how-to-get-more-female-plants-from-regular-seeds.