Did you know seeds — and therefore plants — can be both male and female? Like humans, plants need to have a reproduction mechanism to make new seeds and grow new plants. Most plant species are monoecious, which means they have a reproduction system that allows them to fertilize themselves and produce their own seeds.
But then, there are some plants that grow individual male and female versions of themselves. Cannabis, willow, and kiwis are three examples of species that produce specific male and female plants. With these, the female plant needs to be fertilized by the male plant in order to generate new seeds.
However, in the case of cannabis, what is important to realize is that the male and female plants aren’t exactly created equal. In fact, if you plant weed in your backyard without considering whether you were planting male or female cannabis seeds, you might find yourself very disappointed.
Let’s explore why.
What’s the difference between male and female cannabis plants?
If you don’t know the difference between male and female weed, don’t worry! First, it becomes really obvious as your plants get older. And, this article will also address how to assess the gender if your plants are young. For now, let’s first examine the differences between the two.
The biggest and most important difference between male and female marijuana plants is that female plants produce buds and male plants do not.
So obviously, if you’re growing marijuana to harvest and smoke the buds, you want to make sure you’re planting seeds that will produce female plants, right?
That’s not to say there is nothing good brewing inside a male cannabis plant. The males will still have THC and other cannabinoids in their leaves and stems that can be harvested in the form of resin, hash oil, dabs, or other concentrates.
But for most growers, the priority is to have plenty of large, healthy, colourful buds ready to harvest, dry, and grind, and those beautiful flowers are what we’re looking for.
You’ll want to know early on if you’ve got female or male plants on your hands… more about why in just a minute.
First, let’s explore how you can tell what kind of gender your plants are.
How can I sex my cannabis plant?
If you’ve got a mature plant, you should be able to easily tell whether or not you have a female or male plant because they look different in a number of ways. Female plants tend to be bushier and have thicker, fuller leaves. Of course, the lady plants also make the largest, most beautiful flowers, too. Male plants look a little shaggier and thinner, and won’t produce large buds, if they produce any at all.
But if you just recently planted seeds or if your plants have recently gone through the process of germination, you can use another method of ‘sexing’ your cannabis, which just means, looking for the plants’ reproductive organs.
To sex your plant, you’ll need to wait until your plant is about 6-weeks post-germination. The exact timeframe will depend on where you are growing, how much light your plants get, what strain you’re growing, etc.
Both genders produce pre-flowers and flowers in the gaps between their stems and branches. So at this early stage, you’ll want to look in the junction between the main plant stalk and one of the stems, usually close to the top of the plant.
The males usually develop first, and what you may see is a round ‘ball’ like sack that contains the plant’s pollen. At first, the ball may be nestled against the plant stem, but in time, it will begin to protrude from the plant on the end of what looks like a tiny stick. This pre-flower is called the staminate. The staminate will eventually look like a hanging bunch of bananas, and you’ll definitely want to cull (remove) the male plants before they’ve reached this point.
Female plant sex organs have a more oval shape with a long, pointed tip. This is called a calyx. Sometimes, pistils emerge and extend from the calyx; they are fine, white and hair-like, but not every cannabis plant will have pistils.
Of course, you can wait till plants are older to see how bushy or large the plants get, but by that point, your male plants may have opened their pollen sacks to pollinate the female plants… and that’s what you want to avoid.
Why do feminine seeds matter? Should I plant a mix of both?
We’ve talked a lot about the different plant genders, but now let’s talk about why we want to separate female and male cannabis plants.
Plants need to be fertilized to make new seeds. ‘Great!’ you’re thinking! We need new seeds, right?
Fertilization happens when a male plant opens its pollen sacks and releases the pollen into the air. The female plant’s flowers capture the pollen. This process of pollination fertilizes the female plant’s eggs, similar to how babies are made! The female plant then produces seeds that can grow new plants.
The problem is, once this process begins, the female plants get a little sleepy. Like pregnant moms who are tired and have little time for primping, they’ll spend their energy growing seeds instead of producing flowers.
If you’re growing marijuana for the buds, you don’t want your plant’s energy going into producing seeds! You want big fat flowers!
Conversely, if your female plant is denied the ability to be fertilized, she’ll spend extra energy making buds! She’ll try to make them bigger, stickier, and sweeter to try to capture pollen in the air! Keeping her away from male plants is exceptionally beneficial for your grow.
This is why many people prefer to plant feminized cannabis seeds.
It’s now possible in plant breeding to cultivate plants that make almost all female seeds. While feminized seeds might produce a male plant, the likelihood is only about 1%, so you’ve got a 99% chance of growing a female plant if you purchase and begin your grow with feminized seeds.
Since many provincial laws only allow you to grow four plants at once, you can increase the likelihood you’ll grow female flowers if you start with feminized seed from seed banks.
For a small home crop, you don’t need to plant a mix of both, and only those interested in harvesting their own seeds will see a need to grow both genders. So buying feminized seeds may be in your best interest, especially if you’re new to growing.
How are plants cultivated to produce female seeds?
By now, you’re likely wondering how seed harvesters tell the difference between male and female seeds. Unfortunately, they can’t. What they can do, however, is grow seeds that have a greater chance of being feminized seeds; these plants are more likely to grow into feminine plants.
In order to do this, the plants need to be treated in a way that inhibits male chromosomes. If the plant isn’t making male chromosomes, it’s less likely to produce male seeds. The most common way to produce feminized seeds is to spray the plants daily with colloidal silver. There are other chemicals that can be used as well, but colloidal silver is most easily accessible.
Spraying the plants with colloidal silver makes them unusable, however, so you only want to feminize seeds if you’re growing cannabis to harvest seeds alone. The plant will need to be destroyed after it’s been treated and the seeds have been harvested.
Growing cannabis isn’t overly complicated. But there is a lot to learn in order to make your time and energy worthwhile. If you’re considering growing cannabis from seeds, learn more about the process here.