When can you sex your cannabis plants? Well, the earlier you attempt to determine the sex of a plant, the harder it is because until the reproductive structures appear, there's not really a visible difference. Some growers will say you can use characteristics such as height and girth, but this isn't always, if ever, truly effective. Additionally, different cultivars will vary based on their phenotypes so what might make a good identifying characteristic for one type of plant, wouldn't necessarily hold true for another variety. Even investigating the genetic origins of your cannabis seeds will be very little help.
The most common way to sex your plants, is to examine the reproductive parts. If you see little, round pods at the nodes where the fan leaves attach to the main stem, you're looking at pollen sacs and you have a male. These sex organs begin to develop around the time you want to move to flower so make sure you check them every day and remove males as soon as you identify them. You can distinguish the male pods from the female pistils because the male organs tend to be extra rounded and plump. The females' pistils are longer, thinner, and hair-like.
Female Cannabis Plants
As mentioned above, female cannabis plants exhibit their first sex characteristic about the time they are ready to enter the flowering cycle. At this time, the thin, hair-like pistils emerge at the nodes where the flowers will grow.
Depending on how long your vegetative cycle is, your females may start producing their pistils before you move them to flower. So, if you see wispy white hair developing on the plant late in veg or as you begin flowering, you have a female plant.
Male Cannabis Plants
Male cannabis plants sex organs look like tiny little spheres growing on the nodes, the same location as your pistils. If left to mature, the pollen sacks will open and pollinate your females, the way flowering plants reproduce in the wild. More than likely however, you don't want your males to pollinate your females. Most growers interested in growing quality flower remove the males as soon as they're identified to keep their buds seedless and potent. which develop and fill with pollen. Like with the female plants, you'll notice the males' pollen sacks developing late in veg or early in flower. You still have a little time before the males are mature enough to spread their pollen, but you should remove the males as soon as they're identified.
How to determine female plants if starting out with regular seeds
You don’t have to wait for the flowering stage! There are two proper ways to use to determine a plant's sex in the vegetative stage. Of course, this step can be avoided with feminized seeds, but if you have regular seeds, read on!
1: Examining the Pre-Flowers
Pre-flowers expose the gender of your plant by around 6 weeks from seed, and as early as 3 weeks from cannabis seed for some plants. In this expanse, you’ll find pre-flowers packed at the nodes of the plant.
2: Using Clones
The following process can help you distinguish the gender of a plant even before pre-flowering. If you’re just growing 1, 2, or 3 plants, it can be unbearable to find out all your plants are male, and you need to begin over to produce buds so the earlier you can sex your plants, the better!
When cannabis seeds are still in the germination stage, there’s no way to determine which plants are male or female. You have to “wait and see.” Male cannabis plants eventually produce their pollen sacs, and female cannabis plants begin to develop white hairs that spread into the flowers that contain THC and other cannabinoids.
How to Sex Your Plants from Clones
You can wait until your plants simply show the earliest signs of their gender and then exclude all the males, but that means you have to inspect the plants continually until the first signs of their reproductive organs appear. A downside to this method is the time and energy wasted nurturing male plants. Again, unless you're breeding, get rid of all male plants right away.
- Take a clone from an unverified cannabis plant
- Mark both the clone and the mother plant, so you recognize which clone originated from which the corresponding mother. If you don’t label them clearly, then all your work will go to waste
- Once the clones have developed roots, grow just the clones into flowering mode by giving them a photo-period of 12 hours on and 12 hours off.
- The clones should start exposing their gender in a week or two. Males will start forming balls, and females will begin producing white hairs.
- Once you have determined the gender of your clones, you should make sure you remove and destroy male plants.
As a final thought, you need to be proactive and get rid off the male plants before they begin releasing pollen. You don’t want to waste your time an energy tending to plants you're going to get rid of anyway and you probably don't want your flower full of seeds. If this sounds like you, remember to sex your plants!
Growers Network would like to thank Shanta for providing this contributor article. What did you think? How do you sex your cannabis plants? Join our community of growers and start a conversation. Just click one of the "Join Now" buttons on this page. See you there!
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About the Author
Shanta Devourn is a multipotentialite who loves to create possibilities in terms of his writings. Shanta support educational awareness in online platforms. She believes in the saying "Understanding other viewpoints are enhanced when done so through outspoken synergy with those who have a different perspective as long as the situation is secure, and the idea is well-crafted." You can find her on Twitter (https://twitter.com/SDevourn) and Facebook (https://www.facebook.com/shanta.devourn.7).