Determining Sex Of Cannabis Pre-Flowering
So this area is pretty tricky because it takes a while before the plant will develop calyx but that doesn’t mean that you can’t prepare for this moment. To start off as with a lot of organisms the male grows more in the early stages of its life.
Now this is not an exact science because females can get to similar heights. I would recommend moving the taller ones away from the rest or at least mark them down as potential males.
As I’ve said before you need to move plants often to avoid competition among your crops when growing indoors. The next thing to look for is the calyx development. When calyx starts to develop you may notice certain properties.
If your calyx is raised on a small stem then it most likely is a male plant and if the calyx isn’t raised then it is most likely female. This can be tricky to see with the naked eye, so i would recommend having a fine magnifying glass. They are a small part of the plant and sometimes it can be hard to determine if they are raised without getting super close.
Now these two methods are not 100% accurate but provide an educated guess on which plants will turn out male and female. There is one more way to determine sex. You can do a force-flowering sexing where you take a single cutting and introduce it to the 12/12 cycle.
Cannabis doesn’t determine it’s sex until the third week of growth so this method does require you to wait for the plant to mature enough to show it’s sex.
Even after all these tests it is still not 100% accurate but you will have a strong idea of the sex of your plants. The only 100% sure way to know happens after the plant goes into the flowering stage.