1) Identifying the Gender of Your Cannabis Plant

What do they say? Men are from Mars and women are from Venus… Identification and separation of male and female plants is a very important aspect in the cultivation of regular cannabis seeds. If you don’t recognize the signs it could cost you your crop! 

Female cannabis plants produce cannabis flowers, which are used for medical and recreational purposes. On the other hand, male cannabis has minimal amounts of active cannabis compounds (cannabinoids) and produce pollen pouches instead of flowers. Their role in cannabis plant life is only to spread that seed! 

When the pollen of a male cannabis plant reaches a female (through pollination) then fertilization takes place, and the female plant will start producing seeds like crazy. The plant puts all its energy into the production of seeds (comparable with the body putting all its energy into producing a child in a pregnant woman) and not putting its energy into producing big fat buds.  

So if you want to harvest cannabis BUDS instead of seeds, make sure you separate the males from the females before the males can pollinate the ladies. So, next question… How do you know if you have a male hiding out in your grow room?!

male early sexfemale early sex

After 10 flowering days (12/12 light schedule) the cannabis plant will reveal its gender (in the pre-flowering phase). Luckily you can visually recognize if you have any males. To do this, check the nodes of the plant in the second and third week of the flowering-phase; this is where the petioles (the stalk that attaches the leaf blade to the stem) meets the stem (I always describe these as the ‘armpits’ of the plant! See the graphic below).

Determining Gender ASC

It’s quite simple. If you see what looks like small balls you have a male. If you see pistils (like a thin hair) you have a female. Simple! As soon as you have identified a male, get rid of it!


2) Lifecycle-Phases: Growing & Flowering

Cannabis passes through two phases in its lifecycle, the growing/vegetative phase and the flowering phase. I have described all the aspects of these two phases in more detail in my previous columns, but you can find them here: GROW & FLOWER. In the vegetative-phase cannabis plants only focus on growing taller, bigger and stronger. Showing sex is less relevant in this lifecycle phase.


3) Hermaphroditism

Hermaphrodites or ‘hermies’ are female cannabis plants in which the flowers develop male genitals to fertilize themselves (self-pollination). The result: buds that are filled with seeds, which is undesirable for any smoker! 

Why do Cannabis Plants turn Hermaphrodite?

1) Stress


In most cases hermaphroditism is the result of a plant’s response to stress. Environmental changes are the main source of stress, causing a female cannabis plant to ‘herm’. For example: if your plants receive more than 12 hours of light during the flowering-phase then they will become stressed and confused. It's not clear to your plants whether they should grow or flower. In most cases like this they'll become hermaphrodites (hermies) or revert back into the vegetative phase.

PLEASE NOTE: A common mistake made by beginner growers is taking a peek in to their grow tent when the lights are off during the flowering-phase. Even the slightest ray of light may wake the plants from their sleep and cause confusion to their system.

For outdoor growers, be aware that the same disruption to plants’ sleeping habits can come from streetlights or garden lights.


2) Genetics/Cultivars

Stress is not the only cause of hermaphroditism. Hermaphroditic tendencies can be a genetic makeup; this means that it is already ‘written’ in the genetics that the female plant will become a hermie. Experienced growers claim that Feminized cannabis seeds, have a greater tendency for hermaphroditism compared to Regular seeds. But why?

I would explain it like this: Feminized cannabis seeds are made by manipulating the female plant. Regular cannabis seeds are made the ‘natural’ way, by crossing a male plant with a female plant.

So back to feminized (fems) seeds; Fems are made by ‘transforming’/’reversing’ the female plant to a male plant. This can be done by spraying STS (silver thiosulfate) on to a female plant, during the flowering-period. This will turn the female plant into a male plant, meaning that instead of flowers, she (or should I say he!) will start to produce pollen pouches. This pollen is used to pollinate a copy (clone) or a different (cross-breeding) female plant to make feminized seeds.

So to sum it all up, a female is made into a male to pollinate a ‘healthy and natural’ female. Will that cause a tendency to produce hermies in the genetic makeup? Let’s just say, from our ASC experience with many thousands of feminized seeds, the percentage of hermies produced by the brands that we carry is tiny.