Sexing cannabis (and no, I don't mean getting down and dirty with your favourite weed plant) is just one of a lengthy list of essential skills that all budding weed growers need to master.
Knowing how to determine the sex of your cannabis plants (if you decide to grow regular seeds) can and will make all the difference come harvest time, and for a few key reasons.
Even if you only grow feminized seeds, there is always an exceedingly small chance that a seed may turn into a male plant - less than 0.1% of feminized or autoflowering seeds will turn out male, but it is still possible. There is also the rare occurrence of hermaphroditism, which occurs when a plant produces both male and female flowers.
In today's write-up, I am going to run through everything there is to know about sexing cannabis plants - don't worry, it's all pretty straightforward, and in a few minutes, you'll be armed with all the knowledge you need.
What is sexing cannabis?
Sexing weed plants is simply determining the gender before the flowering stage of growth goes into full swing. This is important because, as you all should already know, it's the ladies we are looking for (unless you are trying to breed your own strains).
But why?
What is the difference between male and female weed plants?
Male vs female cannabis plants
Male Cannabis Plants
The dudes usually grow a bit taller and have fewer leaves. They produce small clusters of pollen sacs, which can resemble small little balls (or sometimes bananas if your plant turns hermaphrodite). These sacs may form at the nodes of the plant (where the branches meet the stem).
Female Plants
Usually, a little bushier with more fan leaves. They develop wispy white or amber colored pistils (hairs) that emerge from the calyxes (the base of the flower). These pistils catch pollen to produce seeds.
Cannabinoid and Terpene Production:
- Male Plants: The vast majority of cannabinoids (THC, CBD, CBG, etc.) and terpenes are produced in the trichomes, which are found in the highest concentrations on the buds (flowers). Male plants do not grow flowers, so they produce much lower levels of cannabinoids compared to females. Their job is to produce the pollen that will fertilize the females.
- Female Plants: The ladies are the ones we want because they produce the flowers, which are covered in those glistening, gorgeous trichomes, jam-packed with all the cannabinoids and terpenes we are all looking for.
Reproductive Role:
- Male Plants: Out of those tiny little balls comes the pollen that fertilizes the female plants' flowers, allowing them to produce seeds. THE LAST THING THAT MOST GROWERS WANT IS POLLEN TO BE FLOATING AROUND THEIR FEMALE WEED PLANTS, AS THIS WILL RESULT IN SEEDS. If this happens, the plant will put its energy into producing seeds instead of growing big, juicy buds.
- Female Plants: The pistils on female plants catch and hold onto pollen, allowing for the development of seeds. However, when unpollinated, the plants put all of their energy into producing trichomes and buds, making for the best final product possible.
Why is it important to separate male and female cannabis plants?
It's simple - unless you are interested in starting your own breeding program, you do not want your female plants to be anywhere near the boys.
A single male plant produces enough pollen to pollinate an entire crop of female plants. The pollen can travel a surprisingly long way, up to around 3 miles.
This means that if you have a male plant in your garden (even one single male), chances are, you will end up with a crop of seeded buds. When pollinated, female plants push a lot of their energy into producing seeds rather than buds - this results in a lower-quality final product.
What are the different ways of sexing cannabis plants?
There are a few ways that growers use to work out if they have a male or female plant growing, but really, for almost all growers, there is just one foolproof method that you will need to know. That is, to wait until the 'pre-flowers’.
Male and female pre-flowers
Pre-flowers are tiny little growths that appear on the plant during the 'pre-flowering stage'.
- Females will produce pre-flowers with a calyx, which looks like a little teardrop-shaped pod. This is where the pistils (hairs) grow out of.
- Male pre-flowers typically appear as small, round balls clustered at the nodes. These will eventually develop into pollen sacs that dangle from the plant if not removed.
- This happens for most strains after around 5 to 7 weeks of vegetative growth, but if you switch your lighting schedule to 12/12 before this time, then pre-flowers should appear within a week or two.
- Male pre-flowers almost always show up around a week before females (if the seeds are planted at the same time and they are the same strain), but this isn't a fixed rule.
Cloning to test for gender
The one surefire way of determining whether a plant is male or female before the pre-flowering stage hits is to take a cutting (or clone) and then force that clone into the flowering stage of growth.
This is easy enough to do, as long as you have a separate indoor growing area and spare grow light - and you don't mind slightly reducing the size of your main plant.
- Usually, when we take cutting from a mother plant to make clones, we don't have to worry about whether the cutting already has a node. But this is important if we want to sex the plant at an early stage, as the node is where the pre-flowers show.
- Once you have your cutting, treat it like you would any other clone, with one big caveat. That is, put it directly under 12 hours of light per day to induce flowering, rather than allowing it to first go through a few weeks of vegetative growth.
- If your clone is female, you should get little white hairs growing at the nodes (pre-flowers) within a week or two. If it's male, you'll get those small ball-like growths. Easy.
Cannabis sexing FAQs
Can you tell the sex of cannabis from seeds?
No, there is no way to visually determine the sex of the plants from seeds.
Can a male plant turn into a female?
No, but female plants can turn into hermaphrodites if they are exposed to heavy stress, resulting in both male and female reproductive parts. This can happen due to environmental factors such as light, temperature, and pH levels, or if you over stress the plant through excessive pruning or training.
Are there any smokeable parts on male cannabis plants?
Not really, or at least no flowers or buds that contain high levels of cannabinoids and terpenes.
Other parts of weed plants do produce very low levels of cannabinoids, but nowhere near enough for it to be worth trying to smoke.
