How to tell male cannabis plants from female ones?

Before we start answering this question, it's worth explaining why it's important to differentiate between female and male cannabis plants.

Let’s say someone decided to buy some regular seeds for a good price from an online store to grow a few beautiful plants on their balcony. They want big, resinous buds from their plants. They want sensimilla—a female plant that waits 2-2.5 months for pollination but never gets it, fully matures, and accumulates the maximum amount of THC in its buds.

But what if a male plant grows nearby and pollinates our “sexually frustrated” girl? If that happens, the fertilized female buds will start producing seeds. Seeds don’t contain THC, because after pollination, the female plant stops producing it, focusing all its energy on making strong, viable seeds.

This is great if the person wants cannabis seeds as their harvest, but more likely, they’re aiming for something else entirely.

In short, pollination is devastating for your harvest. This is why male cannabis plants must be separated as soon as their gender is identified.

So, how do you do that?

Young cannabis plants usually start showing their sex around the 4th week of the vegetative phase, about 6-8 weeks after planting. You should look for sex characteristics “...between the fourth and sixth nodes, counting from the base of the plant...” “...in the branch internode, just behind the leaf stem or stipule...” as advised by Jorge Cervantes. It may sound confusing, but the images will help.

In the images below, you can see the pre-flowers of a female plant—white V-shaped pistils:

      

 

Male pre-flowers, on the other hand, look like tiny nodules located above the internodes.

Here, just above the dirty nail, you can see a tiny nodule:

 

In the next image, the sex characteristics of cannabis are circled in yellow.

 

In the last picture, the male plant has clearly revealed itself:

 

If allowed to continue developing, the male plant will grow “balls,” as you can see in the following images.

      

 

The female plant, on the other hand, blooms much more beautifully, and we believe that’s only fair.

To minimize the chances of male plants among your cannabis crop, choose feminized cannabis seeds. In that case, about 99% of all seedlings will be female. However, if you prefer regular cannabis seeds, the chance of male and female plants will be 50/50. Be vigilant and separate the male plants in time.