Determining the Sex of Your Plant


One of the biggest drawbacks of growing marijuana is the fact that one day you will need to sex your plants. But the good news is it’s not as hard as it seems. In this article, I will explain the ways to tell how to identify the sex of your plant and hopefully make it a bit easier on you when the time comes.

First, let me start by saying there are three different sexes to look for, that’s right: three. When we grow flowers, we are aiming for a tent full of just females since they produce the beautiful flowers we all enjoy. Next, there are the male plants: believe it or not, males do have their place in the grow as the males fertilize females, which then produce seeds, so if you like the strain you can collect seeds for future crops. The third cannabis sex is hermaphroditic, or intersex, whichever you are comfortable with.

How to spot each sex and what to do when they are spotted

First up is the easiest to tell, this is the female. Oftentimes, female cannabis plants grow shorter than their male counterparts—this is an evolutionary trait that helps females collect pollen from the larger males, but this is not always the case so we will have to look for other detail to identify the sex of our plant. Usually, we can identify a female with the naked eye but it doesn’t hurt to use a magnifying glass or jewelry loupe to make it easier.

First, we look around the main stalk of the plant and then at the nodes (the spots where branches sprout from the main stem)—right at the point where the nodes and the stalk meet. The easiest place to find signs of sex is at the top of the plant where new growth is emerging since plants will show signs of maturing at the newest structures. We are searching for “white hairs” (stigmas) coming from a Calyx, a small, round spongy node—these hairs will be very apparent when you look closely. They may vary in color slightly, but they will appear to be a part of the Calyx when you look at them. These can be pretty small so that is why a magnifying glass comes in handy. Refer to this picture to get an idea of what to look for.

Stigmas from a Calyx

When you see this, do a happy dance because you have a female in your garden.

Next, we’ll look for males. Unless you want to preserve genetics or make more seeds, growers usually chop males down to make room for more flowering plants. Males usually grow faster and taller than females—but not always, which is why we must always be on the lookout. Males will usually show “preflowers” before the females begin to produce, so we should be able to find males before we identify females. It’s good practice to always be checking on your plants during the seedling and vegetative stages if you have not yet sexed them—if you do not plan to fertilize females, you need to remove the males as soon as you can.

Like we described when checking the sex of a female plant, you’ll be checking in the same place for the male: along the main stalk, but this time instead of looking for hairs, look for a round “ball” shape that might be a bit harder and will lack the tell-tale hairs of females. These balls may grow by themselves or may grow in small clusters, and they will eventually grow big enough to produce pollen, but this does not happen for several weeks, so you’ll have plenty of time to make sure the plant actually is a male before you throw it out.

A Round Ball Shape of the Male Plant

The males will only drop pollen when clusters of balls form and will open usually one or two weeks after the stage in this picture. If you do not want seeded flowers you’ll need to chop them down before this stage.

Finally, we’ll have to address a worst-case scenario for a lot of growers. So you have a female and your grow is going great, but when you harvest you notice seeds have emerged even though you were certain you removed all of the males from the room. Usually, this means that one of your females had intersex traits. This happens for several reasons, mainly because of stresses in the environment or genetic predispositions or changes that occur naturally.

Let’s look at how to spot intersex plants and what to do if you find one. Whenever you begin growing a new strain or seeds that you yourself did not cultivate (or any new plant, really), you should be checking the plant regularly for pests, overall health, and whether the plant has begun developing male reproductive organs. We recommend checking your plant’s health regularly and rolling this check into your normal routine.

If you do spot a hermaphroditic plant, you should also begin checking your growing environment: Intersex Changes occur likely because something is wrong, it could be light leaks, over-watering, watering, or any number of other issues. This is another reason we believe you need to consistently record changes in the environment. Remember, cannabis plants are hermaphroditic as a response to environmental stresses—it is actually evolutionarily a net benefit for the species to do so—so make sure your environment is as good as it can be.

So what should you look for when checking whether your plant is intersex? Check the following photograph for an example. It can be a bit harder to spot hermaphroditic plants as sometimes the male pollen sacks develop inside the buds. In grower terms, we call these “bananas,” since when the sacks open up they look like tiny bananas.

An Intersex Plant

To add a little more detail to this, a “true hermaphrodite” is a plant that has both male and female organs, while a “mixed gender” plant has both sexual organs contained within the buds (“bananas”).

When we spot an intersex plant sadly the best thing to do is to chop it down, look for problems with the growing environment, and start over. This way we can ensure we end up with seedless flowers.

Determining the sex isn’t as scary as it seems, and even when we get feminized seeds it is always best to look over them throughout the grow to make sure they stay 100% true female. Of course, it is a sad day when you lose a plant, but it is a part of the growing process. If you want to limit the risk of getting a male plant or a hermaphroditic plant, you can try cloning one of your mature plants—but that is a conversation for a different article.

As always if you have any questions you can message our Instagram or Facebook and we’ll be glad to help you out! We’re happy you’re on this journey and we want to help in any way we can.

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