how to tell male from female cannabis plant

Sexing 101: How to Tell Male From Female Cannabis Plants

While cannabis is dioecious, meaning it can be male or female, the plants we smoke are exclusively female. Female plants are responsible for the resin-secreting flowers we all know and love, and to do so must be kept from pollinating males. That’s because female plants, once fertilized, convert energy from THC production to seeding. Hence, the females we consume are “sinsemilla” or seedless.

Male plants are still necessary for cannabis production when it comes to propagation and breeding, however. For a female plant to produce seeds, it requires pollination from a male plant. Without further adieu, let’s dive into how to tell male from female cannabis plants.

Properly sexing cannabis is easier with more mature plants, but there are several key ways to sex cannabis in the pre-flower phase.

Identifying a male cannabis plant

male cannabis plants
Male cannabis plant, photo courtesy of Royal Queen Seeds

Pre-flowers will appear at the base of the leaves when male plants are about three to four weeks old. In females, they appear between four to six weeks old. Males can be sexed as early as one to three weeks before germination. However, it’s best to identify and cull males before they begin developing pollen sacs.

One male is enough to wreak havoc on a harvest.

Male pre-flower are staminates, and the female pre-flowers are pistils. Staminate will be more rounded than pistils and take on a spade-like shape. Look for them at the joints on the stalks of the flower. As it matures, the staminate takes on a curved blade shape and a round spade or ball.

Can you smoke them?

Technically yes, but in the immortal words of Obi-Wan: these are not the cannabinoids you’re looking for. The quality THC we get from cannabis is from seedless females. Males just don’t contain the same quantity of things that we look for in cannabis to consume. Sure, males do produce some trichomes, but the amount and quality pale in comparison to females. Besides, allowing a male to reach the point of maturity where it produces cannabinoids and terpenes at all will have already pollinated the females and ruined your harvest.

Identifying female cannabis plants

female cannabis plants
Female cannabis plant, photo courtesy of Pexels

Like males, pre-flowering female plants will have bulbs too, but these are more pear-shaped rather than spades. The dead giveaway is long translucent hairs called stigma. The stigma is part of the pistil and will definitively identify the plant as female. Female plants all produce pistils; the problem with sexing female plants is not every female plant in the pre-flower phase has pistils. 

Hermaphroditic Plants

Another confounding variable is hermaphroditic plants that produce both staminate and pistil. Hermaphroditic plants are typically the result of stress. Treat these plants as males and cull them if looking to harvest, or keep them if looking to seed.

Structural Difference between male and female plant

Lastly, there are also a few morphological differences between males and female cannabis plants to help you sexing your plants. Female plants are typically shorter and bushier, while males grow taller and have thicker stalks to support the additional weight.