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How to identify the sex of your cannabis plant

When we talk about growing cannabis for recreational or medicinal use, we are predominantly focused on the growing of female plants. Cannabis is a dioecious species, which means that the  reproductive organs of the plant occur on separate specimens resulting in distinctly male and female plants. Occasionally both male and female flowers occur on the same plant – these are known as hermaphrodites.  

Because of our focus on producing female flowers, identifying males from females and females from hermaphrodites is of utmost importance. If males or hermaphrodites are growing alongside female plants, pollination will occur, causing females to create seeds. Flowers, aka ‘buds’ with plenty of seeds are not good to smoke, they taste bad, are very irritating on the throat, and are usually much lower in potency. This is because making seeds is energy intensive, leaving less energy for producing trichomes.

Differentiating males from females is essential if using regular seeds, which have a 50% chance of being male or female.

Why is it so essential to identify males and hermaphrodites?

They both produce pollen, which will cause your female plants to produce hundreds and hundreds of seeds. Unless you are involved in breeding (for which carefully controlled males are necessary), you will need to remove male or hermaphrodite plants as soon as possible.

How do you do this?

It is really easy to identify the males, but can be quite complicated when we talk about hermaphroditism, so let’s start with male and female.


Cannabis plants often show their sex when they reach adulthood and are ready to flower. Normally this comes after the first month of vegetation (3 weeks on autoflowering). For those who grow indoors and do so with short vegetative times of less than 1 month, it is feasible to see their sex from the first 3-5 days with the lights on 12/12.

To certify sex, you only have to look at the nodes of the main stem (it is always better to look at the highest nodes, as sex usually shows there first). Male plants at first may look like a female’s sacks, but in a very short time, if not hours, you will see more and more sacks appear that turn into clusters of male flowers, which are like balls with a cluster of banana-like sacks inside, each of which contains large amounts of pollen. It can be a matter of just a few days from the time they start appearing until the first ones start to open, which is why it is so important to quickly identify the males and shield your females from any source of pollen. It goes without saying, that if you want to cross breed, a good male must be saved.

SHOT AT DAY 21 to 12/12 of a Regular seed – Male

The female plants will show a small sac from which two V-shaped white hairs will emerge, these are called pistils. Once you see this in your plants you can relax – they are 100% female. Even so, we recommend checking your plants periodically, especially if they are suffering from some type of stress, as this can occasionally cause male flowers to appear turning your female into a hermaphrodite.



Hermaphrodite plants are those that show both sexes; there are two types – those that show both sexes from beginning to end, and those that result from stress (most common stresses are heat, cold, high or low nutrition, extreme pruning). The first group are easy to identify, since they produce both sexes at the same time and usually do it from the start, which greatly facilitates the task of identifying and banishing. For the second group, this is more complicated, because these plants can produce very few or very many male flowers, depending on the stress level and how susceptible the genetics are. The problem, of course, is serious in those with a high incidence of male flowers, but just as dangerous with a few, since it only takes a few of the banana-like sacks (flowers) to open and there is enough pollen to pollinate a large portion of your female buds.

SHOT AT DAY 21 to 12/12 of a Regular seed – Male

To this, we must add the difficulty of finding these sacks when the plant is already in advanced flowering, since normally, the individual banana-like flowers (the latter are usually shown in the middle of the buds, almost always hidden between pistils) are hidden by the leaves of the buds forming. For these types of plants, we cannot let our guard down, especially in plants with problems. The most recommended solution is to eliminate this type of plant as soon as you identify it so as not to have any more trouble. Hermaphrodite pollen is not usually used for breeding since it has a high probability of maintaining hermaphroditism in the offspring.


This should be all you need to know to grow your buds free of seeds. Happy growing!

Cultivation information, and media is given for those of our clients who live in countries where cannabis cultivation is decriminalised or legal, or to those that operate within a licensed model. We encourage all readers to be aware of their local laws and to ensure they do not break them.

This post is also available in: French


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