sexing pot seeds

Male vs. female cannabis: How to determine the sex of your plant

In the world of plants, reproduction can happen in a variety of ways. Monoecious plants produce two different types of flowers on the same plant, and hermaphrodite plants grow single flowers that have both male and female reproductive organs.

Cannabis is a dioecious plant, meaning male or female reproductive organs appear on different plants.

With cannabis, females are usually isolated away from males—introducing males into a garden will result in pollination, causing females to create seeds.

This is important for a breeder to achieve new genetics, but most growers remove the males to allow females to produce seedless buds, also called sinsemilla. These are the resinous buds that appear on the store shelf; they all come from female plants.

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Seeded buds are generally regarded as low-quality cannabis. When seeds are present, the smoke is harsh and unpleasant.

Female genetics can be guaranteed by obtaining clones and feminized seeds. If, however, you’re working with regular seeds and are unsure of your seed’s sex, knowing how to determine the sex of your plant is vital to developing new genetics, gathering seeds, or growing sinsemilla.

Sexing cannabis plants is easy. Let’s see how to tell.

Check out these additional resources for more info on cannabis seeds:

How to determine the sex of a cannabis plant

Female cannabis pre-flowers grow as tiny bracts with hair-like stigma peeking out. Male plants produce small, round balls at the nodes. (Amy Phung/Leafly)

Cannabis plants show their sex by what grows in between their nodes (where leaves and branches extend from the stalk). Pollen sacs will develop on a male plant to spread seeds and stigma will develop on a female to catch pollen. You can see these differences weeks before they actually start serving their purposes in the reproduction cycle. These are known as “pre-flowers.”

Pre-flowers begin to develop four weeks into growth, but they may take a little longer depending on how quickly the sprouting phase occurs. By the sixth week, you should be able to find the pre-flowers and confidently determine the sex of your plant.

Pre-flowers can initially be extremely small and hard to identify with the naked eye, but you can use a magnifying glass to get a better look. Examine the nodes of the plant and look for either the early growth of small sacs on a male, or two bracts on a female, which will eventually produce the hair-like stigma.

Though there are other methods to determine what sex the plant is, examining pre-flower formation is the most reliable.

Removing males early on is important for two reasons: it frees up space in your garden so females can grow bigger and stronger, and it prevents males from pollinating females.

What are hermaphrodite cannabis plants?

Hermaphrodite cannabis can express both sex organs and self-pollinate. (Amy Phung/Leafly)

When a female plant develops both male and female sex organs, it is considered a hermaphrodite. This means your cannabis plant is now capable of producing pollen that can pollinate your entire garden. “Herming out,” as some call it, is something that generally happens when a plant becomes excessively stressed. Some plant stressors include:

  • Plant damage
  • Bad weather
  • Disease
  • Nutrient deficiencies

There are two types of hermaphrodite plants:

  • A plant that develops both buds and pollen sacs
  • A plant that produces anthers, commonly referred to as “bananas” due to their appearance

While both result in pollen production, true hermaphrodites produce sacs that need to rupture, while anthers are exposed, pollen-producing stamen.

Because this occurs when cannabis is under stress, it’s important to monitor plants after they have been exposed to stressors—indoors: high temperatures or light leaks are often the cause; outdoors: a snapped branch might be repaired and then turn into a hermaphrodite.

The other primary cause of hermaphrodite plants lies in the plant’s genetics. A plant with poor genetics or a history of hermaphrodite development should be avoided to protect your garden. If you notice any pollen sacs or anthers at any point, remove the plant from your garden immediately to prevent pollination of female plants.

If you’re interested in pollinating portions of your crop, remember that pollen is extremely potent and very good at traveling. Keep your males intended for pollination far from your garden space and work carefully with that pollen.

This post was originally published on September 19, 2017. It was most recently updated on February 11, 2020.

Determining the sex of your cannabis plant is vital to achieving your growing goals. Luckily, sexing cannabis plants is easier than one might think.

sexing marijuana seeds

Well, let us tell you now, it is all a load of bollocks. There is no way to tell the difference between male and female cannabis seeds by looking at them. In fact, it is widely accepted that the sex of a cannabis plant is not determined until a few weeks before flowering.

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Can You Tell The Sex Of Cannabis Seeds?

For those who don’t use feminized seeds, being able to tell the sex of a cannabis seed by looking at it would be a pretty handy skill. But is it possible?

If you are a veteran of the cannabis community, or spent a lot of your time reading up on cannabis, you may have heard that it is possible to tell the sex of cannabis seed simply from its appearance. There is even a chart floating about out there that describes the physical differences between male and female seeds.

Well, let us tell you now, it is all a load of bollocks. There is no way to tell the difference between male and female cannabis seeds by looking at them. In fact, it is widely accepted that the sex of a cannabis plant is not determined until a few weeks before flowering.

Even feminized seed, which have been bred to have 99.9% chance of growing female, can turn into male or hermaphrodite plants if put under a ton of stress while growing. This is very rarely a worry for feminized growers, as they don’t tend to stress out their plants to this extreme extent – but it is possible.

Think about it. Why would breeders across the globe go to all the effort required to produce feminized cannabis seeds if they could simply look at regular cannabis seeds and categorize them? It isn’t some conspiracy or well-kept trade secret.


While being able to determine the sex of a cannabis seed by looking at it is a myth, being able to sex your cannabis early isn’t.

Normally, you would wait until your cannabis plants are done with vegetative growth, and switch them over to flowering. You then watch like a hawk for any signs of sex, and move the males as soon as possible. This is risky, though, because if you leave it too long, you risk the chance of pollination – turning your bud into seeds. Unless you are getting into breeding yourself, this is something you probably want to avoid.

If you don’t want to take the risk, then sexing your cannabis early is pretty easy, and stress-free. It basically involves placing a black bag over a small section of the plant during the vegetative stage to force pre-flowering, before allowing it to revert back. This gives you a clear idea of what sex your plants are, without undue worry, wasted time, or effort.

If you are growing your own cannabis, you are doing it to produce some prime bud. For this reason, it is extremely important to identify.

It is a sad truth that you cannot determine the sex of a seed by looking at it. If you think you can, you have been lucky. Nothing more. However, hopefully, our explanation of the measures you can take to determine the sex of your cannabis plants will help you keep your grow room male free for years to come!

Written by: Zamnesia
Zamnesia has spent years honing its products, ranges, and knowledge of all things psychedelic. Driven by the spirit of Zammy, Zamnesia strives to bring you accurate, factual, and informative content.

This can be beneficial for breeders looking to create a new strain or breed more seeds. For most growers though, it is an undesirable outcome. This is why sexing marijuana plants before that happens is so important.

Male or Female? Sexing Marijuana Plants

Sexing marijuana plants is very important for growers. If this is left unchecked, one plant could destroy an entire crop.

Female and Male Marijuana Plant

Male and female marijuana plants are very different. The main function of a male plant is to collect pollen. This is used to fertilize the female marijuana plant. Eventually, the pollen sac containing that pollen will burst open. When it does, it will rain down on any female plants in the area. Those female plants will then turn their flowers to seed, leaving no buds for the grower.

This can be beneficial for breeders looking to create a new strain or breed more seeds. For most growers though, it is an undesirable outcome. This is why sexing marijuana plants before that happens is so important.

Sexing marijuana plants can be done before the plant reaches full maturity. For males, it can be done when the plant is three to four weeks old. Females can be sexed when they are four to six weeks old. These timeframes are when the pre-flowers will develop.

Within the stem of every marijuana plant, there are stipules. These appear within nodes, in order to support the flower. While the stipules cannot be seen, the nodes can. This is the area where the branch shoots out from the stem. This is where the pollen sac will appear on males, and the buds will form on females.

Pollen sacs on male plants look like small balls. They do not have anything shooting out from them and are fairly symmetrical in shape. They sit right within the node and will continue to until maturity.

Pre-flowers on female plants look quite different. These are elongated and while still symmetrical, are not a ball shape. This pre-flower is known as a calyx, and not a pollen sac. From the calyx pistils will form. These appear as long white hairs, stemming right from the calyx. The calyx will later develop into a bud, or flower.

How to Sex a Marijuana Plant

Looking at the anatomy of a marijuana plant is a great way to sex marijuana plants. However, sexing marijuana plants can be done throughout the entire grow stage as well.

Step 1: Watch how they germinate

This is by no means a foolproof way to determine sex. Many growers have found though, that different sexes of marijuana geminate differently. If the sprout emerges from the seed at the top of bottom, it is likely a female. If the sprout germinates out the side, there is a good chance it is male. But the only way to be 100% sure of gender is to look at their pre-flowers when they develop.

Step 2: Identify growth patterns

Some growers find they can sex their plants during the vegetative stage. This method is most successful if the plants are being grown outdoors or otherwise getting natural light. As the plant grows, females will have more branches. Males tend to be shorter and have fewer branches. While this stage is too early to tell if plants are male or female, it is a good starting point to see which plants need to be watched more carefully later on.

Step 3: Watch for maturity

Although male plants will be shorter during the vegetative stage, they will mature faster than females. This means they will soon start to grow taller. This enables them to drop the pollen in their sacs onto the females and fertilize them. In addition to being taller, male plants will also start to develop pollen sacs as they continue to reach maturity.

Step 4: Look for flowers and pistils

If height and age are not good enough indications, growers can wait until their plant begins to flower. The pollen sacs on a male will open to reveal small white or yellow flowers. Female plants will not show these characteristics. They will form the sticky pistils, meant for catching the pollen dropped on them by the male.

Hermaphrodite Cannabis (Hermies and Nanners)

Sometimes throughout the growth stage, plants will show both female and male parts. This is known as a hermaphrodite, or a hermie, plant. When it happens, it can make sexing marijuana plants even more difficult.

There are two different types of hermie marijuana plants. The first is when the plant simply has both a calyx and pistil and a pollen sac. In these instances, these two anatomical parts will be in separate areas of the plant. Although they may grow close together.

The second type of hermie plant is known as a banana, or nanner for short. In these cases, the pollen sac protrudes from the bud. It is generally longer in shape and hangs down, like a banana. Sometimes, these nanners grow in a bunch, also just like bananas.

If a plant is a hermaphrodite, it is likely due to stress during the grow period. For this reason, it’s important to ensure there are no light leaks in indoor grow spaces and that temperatures are not too high. Outdoors, if a branch snaps off and is then repaired, this could also cause stress that makes the plant turn into a hermie. The other reason for getting a hermie, which is less common, is the marijuana plant is predisposed to hermaphrodite tendencies. This means it is within the genetic makeup of the plant.

Can you sex cannabis seeds?

While sexing marijuana plants that have already begun growing is easy, sexing cannabis seeds is not. In fact, it cannot be done.

This is because environmental factors during the first few weeks of life can greatly affect a plant’s ultimate gender. The plant is not yet sure of what sex it will be and as such, the grower cannot be certain either.

Using the process of identifying where the seeds sprout is the closest one can come to determine the sex of a seed. However, this still has about a 90 percent success rate and is not foolproof.


Sexing cannabis plants before they reach full maturity is important for any grower. It will ensure they yield the buds they are after. It will also ensure they don’t destroy an entire crop because a male turned the female plants beautiful buds into seeds. Following these steps, sexing your marijuana plant will be a breeze!

Well, let us tell you now, it is all a load of bollocks. There is no way to tell the difference between male and female cannabis seeds by looking at them.