Sexing Marijuana Plants: How to Tell Males & Females Apart

how to sex marijuana plants

When I was about to become a cannabis grower, I didn’t even know I was supposed to tell the differences between male and female marijuana plants.

Then I found out, and it was kind of intimidating; I didn’t want to mess up my harvest either! With a few years of experience under my belt, I will help you overcome that rookie fear and get the most out of your harvest.

In this article, we’ll talk about sexing marijuana plants, how to tell the males from the females, and everything else you need to know about your plants’ sex.

The Importance of Sexing Marijuana

Cannabis is a dioecious species. That means each plant in your harvest will have either male or female reproductive organs.

But first, the million-dollar question…

Why Know The Difference Between Male And Female Marijuana Plants?

Well, most cannabis growers are looking for great quality, high-THC buds they can smoke, vaporize, or experiment with in any other way.

Only female plants produce flowers containing the THC amount growers expect, whereas male marijuana barely has any psychoactive properties.

That’s why we need to remove male plants as soon as we identify them. “Well, I’ll just let them sit around and use the female plants,” you might say. No!

Why Do We Need To Remove Male Plants As Soon As Possible?

When you have both male and female plants in your grow room, they’re wired to fulfill a specific natural purpose: reproduce and perpetuate the species.

Now, when your female plants get pollinated by males, the amount of THC will be significantly reduced as the female will invest all of her energy into the seed production process instead of producing rich-THC buds and flowers.

On top of that, male plants can be a real waste of space and time. They can overtake your grow space, restrict females’ growth, drain their energy, and even stop or reduce bud development if they over-pollinate the females.

Without further ado, let’s get down to business.

Male Cannabis Plants

In the early stages, male pre-flowers, which are early pollen sacs, will look very similar to female pre-flowers, only a little bit rounded. These staminate pre-flowers will eventually turn into a long-hanging bundle of banana-resembling pollen sacs.

At a more advanced stage, male flowers will be easy to tell apart because they look like bunches of bananas hanging from the stalk.

close-up of growing male marijuana plant with pollen sacs on stem

Female Cannabis Plants

Instead of pollen sacs, the female plants start as individual pistils or white hairs (occasionally, these may be yellow or pink-tinged) protected at the base by a membranous layer, the calyx.

As flowering progresses, more and more of these pistils will form until they produce the sticky clusters that make up the bud.

top of growing female marijuana plant with pistils

Hermaphrodite Cannabis Plants

Hermaphrodite plants are those that show both male and female reproductive organs. These are sad accidents that can ruin your crop.

On the one hand, some strains are genetically predisposed to grow both reproductive organs. On the other hand, cannabis plants may develop as hermaphrodites as a result of a stressful environment.

When they sense a dire space that threatens their species’ perpetuation, plants simply grow “some balls” to pollinate themselves. Hey, they might ruin your harvest, but nothing more than respect for them. These are the empowered single moms of the plant kingdom.

So, there’s not much you can do if you have a strain genetically predisposed to be hermaphrodite. However, always ensure your plants are happy by keeping your growing space stress-free.

In vegetal language, be mindful of:

  • Disruption in flowering photoperiods (light leaks, etc.)
  • Temperature dropping too low or going too high
  • Giving them enough water
  • Incorrect fertilisation
  • pH imbalance
  • Physical stress (training during flowering stage)

How to Sex Marijuana Plants

There are three main ways to determine the sex of your cannabis plant.

1. Visual Inspection

The easiest and least expensive way is simply by spending that time with your plants and carefully inspecting them. Depending on the particular strain, you will be able to see your plant growing pre-flowers between weeks 4 and 6 from germination. You may even use a jeweler’s loupe for a closer inspection.

Also, when trying to identify the males in your harvest, you’ll want to look for physical traits that usually make each sex distinctive.

Male plants tend to be taller than females. They have thick and sturdy stalks and sparse leaves.

Female plants are shorter and have slender stalks. They have abundant leaves. Also, the presence of fine, translucent hairs in white, orange, or even pink is noticeable. It’s also easy to spot V-shaped pistils with a protective, membranous layer (the calyx).

These structures are the ones that will grow and later develop into resinous buds.

2. Forced Flowering

Forcing the plants to flower is a great way to determine their sex. However, this method is only feasible if you don’t have a large crop and you have the time and resources needed.

If that’s your case, you just need to carefully take labeled cuttings from each plant and force the rooted cuttings to flower by using light cycles. For this, you need to have a separate room and give them a 12-hour darkness cycle.

Then, as soon as the cuttings show their sex (1-2 weeks), you can go ahead and cull the male parent plants from your garden or indoor grow space.

3. Chemical Testing

The third sexing method is a bit more expensive but quite effective. Chemically testing the leaves is a practice that’s becoming more popular as the costs drop.

Chemical leaf tests won’t hurt or slow down your seedlings. It’s actually a method that only requires a tiny amount of plant tissue. A small punch-out from a leaf or a single cotyledon will be enough to determine the plant’s sex and even its potency.

These tests could be conducted as early as week 1 from germination. However, for the sake of accuracy, most companies refuse to perform the testing until week 3.

Regular Seeds vs Feminized Seeds

I know, that’s a lot of info to drop on someone who’s just starting out. But, the good news is that there’s an easy way. That’s the core of human progress: finding an easier way to do stuff.

So, if you want to skip the sex-determining process, you must learn how to feminize seeds or simply buy them from a trusted seed bank.

What are feminized seeds?

Feminized cannabis seeds are seeds that will produce 100% female plants.

Hooray! Well, maybe 99.9% to be on the safe side. Of course, some cons and pros are implied in the choice of growing feminized seeds. However, we can say it’s the absolute favorite for beginners.


Are regular seeds better than feminized seeds?

Ultimately, choosing to grow one or another depends on the grower’s needs and preferences. Each one has a positive and a negative side. For example, feminized seeds are cost-effective and eliminate the risk of pollination.

However, you have a higher chance of getting hermaphrodites, and you’re limited to growing the commercially available strains.

On the other hand, with regular seeds, you have a 50/50 chance of female/male plants, and you need much more space. However, you have a wider variety to choose from, and you can even breed your own strains.

You’ll need to learn how to tell the sex of your marijuana seeds before they become full-grown plants.

Other Uses of Male Cannabis Plants

Now, even if we hurry to cull the male plants as soon as they show, that doesn’t mean males are completely useless. That’s only the typical myth spread by growers who only seek psychoactive effects in their plants.

In the first place, hemp fiber is one of the most resistant and flexible materials ever found to make tablecloths, ropes, and the like. You can use males for the breeding process or simply to set up a grow room where you’ll pollinate females to get seeds.

Not only will you be able to grow from these seeds, but they also make one savory and nutritious snack. Some bulk growers also make hashish and concentrates from male plants. Ultimately, remember that male plants also pull off a lot of nutrients to grow, so why not return those to your soil?

You can either chop them and drop them in the soil, or add them to your compost pile.

Wrapping Up

It’s vital to spot male plants on time if you’re seeking a high-THC harvest. Bear in mind that taking them to a different area of your grow room is not enough to avoid pollination.

Pollen is carried in the air and can travel long distances. So even if you won’t destroy them, be sure to move male plants to a different room if you want them for breeding purposes.

Happy growing!

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