Sexing cannabis plants is important if you want to keep the male plants away from the females. However, you can only find out which cannabis plants are male and which are female once the flowering cycle is underway.
Pre-flowering is usually triggered when the plant receives 12 hours each of light and darkness, within each 24-hour period. During this stage (usually 10 days), they have a rapid growth spurt as the branches get ready to support their flowers. You won’t be able to tell their sex just yet.
Once the plants start flowering, you’ll get the vital clues about whether they’re male or female:Female cannabis plants will show tiny pointed buds at the internodes which will slightly open at the tips and produce two white ‘hairs’ which, if you look closely, appear to be a little fuzzy.Male cannabis plant will produce a few small balls on tiny stems (also appearing at the internodes) which become larger and more oval-shaped, and start to droop.
Top tip – if you want to avoid having to sex your plants, try feminized or autoflowering seeds instead!
Inducing the flowering stage
If you’re growing your cannabis plants inside, you get to decide when the flowering stage commences, simply by adjusting the timers on the lights.
When grown outdoors, it’s slightly trickier. You’ll have to wait until you’re getting 12 hours of light a day – which depends on where (geographically) you’re growing your cannabis.
Alternatively, you can induce flowering by covering the plants when they’ve had 12 hours of sunlight. You’ll have to do this every day though, otherwise the plant may return to a vegetative state.
Top tip – if you don’t want to worry about inducing flowering, Automatic seeds will begin flowering once they reach a certain age and size.
For more info on sexing cannabis plants, you can check out this blog post.