How To Sex Marijuana Plants

Courtesy of Robert Bergman from

When setting out to create a successful marijuana garden, you may not have considered some more subtle aspects, such as organizing your plants according to their sex. You may not have even realized that plants have different sexes unless you have done this type of gardening before.

sex When you are growing cannabis, being able to accurately identify which of your plants are male and which are female is a crucial element in achieving a successful harvest. There are several methods for using this identification to your advantage, and it is important to choose which one is best for your life and growing style.

This article is going to teach you why identifying your plants’ sexes is very important, and how it can positively affect your yield.

Identify female marijuana plants

Female weed plant identification

Your plants will be one sex or the other, depending not only on their genetics, but also environmental factors. Just like other forms of life, marijuana plants all possess two pairs of sex chromosomes. The two possible chromosomes are X-chromosomes and Y-chromosomes, just like with humans.

XY chromosomes are in male plants while XX chromosomes are in female plants. There is an even chance of a plant being male or female when the plants are growing in the wild; you are able to alter these odds when you are able to accurately distinguish male from female.

The flowers from female plants usually do not bloom until after male plants, and they resemble sacks. While they grow, two stigmas that are similar in appearance to feathers will pop out of each of these sacks. The stigmas are located in a node region of the main stalk and are generally cream or white in color.

If you are not familiar already, a node region is the location that a branch is growing from the main stem, or where a branch grows from another branch. They grow this way to catch any pollen that the male plant released into the wind.

Female marijuana plants
Pollination is crucial to be understood because female plants that have been pollinated will stop focusing their valuable energy on their flower growth. Rather, they will use all their energy for seed production, making it undesirable for a successful harvest and a high yield.

You can utilize seeds if you have a particularly successful or hardy strain. If that is the case, then by all means allow a female plant to produce marijuana seeds instead of flowers. Because growers almost always prefer to have more flowers than seeds, they usually take out any male plants that they are able to identify.

Reducing the number of plants has its benefits as well, since any plants that are still there will receive more sunlight and will allow you to focus your efforts on fewer plants, making your work more effective. Since male marijuana plants do not make a good plant for smoking, they are not worth harvesting in the end.  That being said, you can still leave them in the ground to grow, as long as they are kept away from your female plants. This is because you can actually use some of the leaves to add to your pot butter.

Identify male plants

Male weed plant identification

Male cannabis plants begin their flowering phase somewhere between one week and a month earlier than the females do. They do not develop as many flowers as the female plants do, and the plants usually grow straighter. Their flowers generally grow at the top of the plants. At first you would see preflowers developing at the tips of branches and of the main stem. Preflowers are the immature first flowers that come before the more mature flowers form later.

On male plants, flowers come in tight clusters and are green and closed. They have a main part that look like petal-shaped objects, five of which are inside of the sex organs. To the untrained eye, they look like a miniscule banana bunch.

These clusters will start opening over time and a stamen will appear. These are objects that let pollen production occur – and pollen is responsible for natural reproduction in the wild.

Male marijuana plants

So how will you see whether it is a male plant? You have to look at these preflowers before they have matured too far. If at this point there is a calyx that is raised on a small stem or a stalk, then it is most likely a male. If this calyx isn’t raised, then it probably a female plant. You will have to keep a close eye on your plants during their early stages of flower development to become good at distinguishing the two sexes from one another.

Taking out the male plants

Taking out male cannabis plants

The process of removing your male plants from the crop is as simple as uprooting them from the ground. You just take the plant out from the ground. You have to try and do this early on since males that are showing flowers could have already allowed their pollen to be released. It isn’t impossible for pollinated female plants to continue producing flowers and seeds simultaneously, it would require the plant to be extremely healthy for it do this successfully.

How to force flowering

Force flowering outdoor cannabis If you check and organize your plants while they are still quite young (even before their first transplant), you can identify which are females and then decidedly grow only the female plants in your garden. This practice will require you to force flowering when they are quite young, using light controls as your tool of manipulation.

This is, of course, only possible to do with plants that have matured enough to display their sex.

The technique is simple. Once your plants are at least one foot tall, they are surely mature enough to flower (when forced to). To do this, you remove all light for at least 12 uninterrupted hours per day. This mimics the natural changes in the sunlight that would occur with seasonal changes.

These changes send a signal to the plant that it needs to focus its efforts on flowering as much as possible before the weather turns too cold and dark. Once flowers begin popping up at the joints (also known as “nodes”), you should be able to distinguish between the females and males in your bunch.

Once you know which are which, simply remove the male plants from your garden. Then you can pick and choose from your remaining female ones when transplanting – only take the strongest and healthiest for transplantation.

Before you transplant your females, expose them to three full days of nonstop light. This will ensure that your plants won’t continue their flowering process since it would be too early for you to get a harvest.

Download my free marijuana grow guide at this link for more flowering tips

The plants’ processes will go back to normal after they have been transplanted; the natural sunlight should provide many hours of light for the plants. This will make them return to their vegetation stage. This is when the plants will begin again to focus all their incoming energy from the sun; water; and nutrients in the soil on their own growth.

Whatever method you decide to use; it’s a good idea to go for one of them in order to reduce seed production; or maybe get rid of it altogether. Removing male plants will simply take away these risks and will likely lead to a much more successful yield. Proceed with caution, however,; forcing the flowering phase of your female plants can actually occasionally cause sexual dysfunction, such as becoming a hermaphrodite, when one plant exhibits characteristics of both sexes.

The most important thing in choosing the right method is basing the decision on your time and physical space. You also need to keep in mind that removing your male plants from the garden will not completely remove the risk of male plants being present. Sometimes, depending on the area you are growing in; male plants could be present within a close enough range that could lead to pollination of your female plants. This can happen both from male plants that are being grown by someone else; or ones that have naturally cropped up in the wild. Pollen can travel as far as several miles in the wind as well as on birds or bees. They have evolved to be very good at this in order to pollinate female plants and lead to more plants of their species.


Hermaphrodite weed plant

No matter how hard you try, marijuana will do its very best to reproduce; even going to the lengths of reproducing itself without any normal male plants nearby. This is an evolutionary trait just like traits from any other living organism.

If female plants grow male flowers, they run the risk of pollinating themselves or any neighboring female plants. These plants are called hermaphrodites, as they exhibit both male and female characteristics. Hermaphrodites are a natural occurrence – nature’s response to stress. When plants have poor nutrients; too much nitrogen; particularly cold weather; or sometimes when they have been forced to flower; hermaphrodites may appear as the plants’ stress response.

Hermaphrodites that successfully self-pollinate generally lead to more females and more hermaphrodites. When you see hermaphrodite plants in your all-female garden, you may want to practice culling. Culling is when you remove a plant of undesirable characteristics; this is so the overall product does not exhibit these same traits. If you don’t want to remove this plant altogether; simply pluck off the male flower bunches that appear on your hermaphrodite plant. This will restrain the hermaphrodite effects and will keep it from pollinating itself or other plants nearby, and, therefore, will limit its ability to continue its own line of traits.

Thanks for reading.