Starting three weeks into the flowering stage, which occurs between July and September for most growers, start attempting to sex your plants. Plants grown indoors can begin showing signs of their sex this early.
Look for the difference between male and female cannabis. Check the nodes. Look for fine hairs sticking out from oval-shaped protuberances. If you see these hairs, then it is a female. You may also start seeing new growth alongside these pistils. Male cannabis plants, on the other hand, have more rounded ball-shaped pollen sacs that grow at the juncture between the stock and the branches, You may see yellow pollen on these sacs, which means it is time to separate the male and female cannabis plants immediately before cross-contamination occurs. One male can pollinate female plants in a 5 km radius if grown outdoors. Another thing you need to look out for is hermaphrodite plants.
These will show the sex organs of both male and female cannabis. So in one part, you may see the pollen sacs, and in another, you will find pistils. “Hermies,” as they are sometimes referred to, can also be disastrous to your crop. Their pollen sacs will be able to fertilize your females. There is really no need to keep these plants as they generally have poor genetics and will only turn out with the same problems as their mother. However, you can still smoke the bud. It just will not be as potent.
In general, it’s better if you use the hermies to make concentrates. Hermies are often created due to poor lighting, insufficient nutrients or watering, or other damage as the plants grow. So if you have a lot of hermies, you might want to reconsider your growing methods.