Please keep in mind that these traits are not guaranteed, and shouldn’t be the only way to sex cannabis plants! Variations among strains and phenotypes can lead to all sorts of crazy things. The general plant structure simply may help give you a clue if you’re on the fence.
Are you growing cannabis at home, but aren’t sure if your plants are male or female? Then you’ve come to the right place! This article is going to show you how to tell the difference between male and female cannabis plants to properly sex them.
Curious about how feminized seeds are created? In a nutshell: most feminized seeds come from cannabis plants that have been treated and altered in a manner that inhibits male chromosomes. The most common method is to spray the plant repetitively (daily or more) with colloidal silver. Other chemicals and compounds can be used too, but are far less accessible. Colloidal silver is technically “non-toxic”, but you do not want to smoke it! Thus, the plant is sacrificial – used for the production of pollen and seeds only.
My Cannabis Plant is Male! Now What?
Look for plant pre-flowers at the higher stalk/branch junctions, as described above. If needed, use a jeweler’s loupe to get a better look! That is the same magnifying tool commonly used to examine trichomes and determine plant readiness for harvest. Then, locate the stipule, which is a leafy pointed flap that protrudes from the junction. Don’t confuse that for a pre-flower! The cannabis sex parts are located just behind the stipule. Behind the pre-flower sex parts, taller growth tips will emerge – future auxiliary branches that produce buds.
For the most part, the average home grower wants female cannabis plants. The ladies are the ones that produce the fattest, most resinous and most potent flowers – aka buds. Male cannabis plants are only desirable if someone wants to breed cannabis and save seeds (which is a whole other topic for another day). Even then, the grower will want to spot the difference between the male and female plants and separate them early on, unless they want free cross-breeding and pollination between many types of stains.
Until we can tell the sex for sure, we continue to treat the plants equally. We start our seeds in small 4-inch nursery pots. About two weeks after germination, we pot the seedlings up into an approximately two-gallon (trade size) “sexing pot” like these BPA-free nursery pots. This enables everyone to continue to grow in a happy and healthy manner for several more weeks*. Then, once we can surely tell the difference between the male and female cannabis plants, only the ladies move into their forever home – 15 to 25 gallon grow bags full of recycled organic living soil. To learn more about our soil recipe and how we maintain it, see this article.
Our goal here today is to learn how to tell the difference between male and female cannabis plants early on, so you can get the males away from the females as soon as possible! It will help protect your lady plants – but also spare you the wasted time, resources, and energy of tending to male plants that you don’t intend to keep.
While it would be much easier for growers to be able to sex their cannabis seeds, the simple fact is that there’s no way to do it. However, sexing plants early on during their growth period is not only essential, it’s completely possible. Growers can even do it before their plants enter the flowering stage if needed. Then male plants can be removed and growers can enjoy a nice, full crop.
Of all the things that can trip a grower up, sexing marijuana plants may just be the trickiest. Sexing plants is so important because growers are typically after the female plants, that produce the huge THC covered buds. Or the medicinal relief that CBD strains can bring. With such opposite effects of male and female plants, it’s easy to see just how important sexing plants is. But what if growers didn’t have to wait to sex their plants? While it would certainly make life easier, is sexing cannabis seeds possible?
Typically, marijuana plants cannot be sexed until they have already begun to grow. Cannabis seeds will look somewhat identical and plants in the vegetative stage will also look identical,. As the plants move into their flowering stage, they will start to show very clear signs as to what sex they are. While it would be much more convenient for growers to be able to determine sex before this point. The sad truth is that it’s just not possible.
Environment determines sex debate
While environmental factors may not necessarily determine the sex of marijuana plants or cannabis seeds, it is known that certain environments can change the sex of a plant.
The chart states that one can determine the sex of a cannabis seed by just looking at them. Within the chart, five cannabis seeds are shown. Three of these are female and two are male, supposedly. This chart says to look for a crater at the bottom of the seed. It explains that females will have a depression that is perfectly round. While males will have a crater that is misshapen and not uniform. However, this is simply not true. The craters found in cannabis seeds have nothing to do with the sex of a seed.
We know that determining the sex of cannabis seeds cannot be done. However, it’s unclear as to whether environmental factors have any place in determining the sex of marijuana plants.
While growers may not be able to determine the sex of a seed, does the environment have anything to do with it? This is something else that has been hotly contested online.
For those who have the desire to make your own custom genetic crosses, starting your own breeding project in the comfort of your own home is easily achievable. For this you will need to invest in regular seeds that will allow you to grow either male or female plants. It is a good idea to start with at least 10 seeds to allow for a much wider variation, and greater choice of male to females. Some seedlings may underperform and be discarded early on, however with 10 seedlings, there is a good potential desired ratio. Labeling your pots with numbers and strain names, will make life much easier when sorting through the different plants, especially when taking cuttings before flowering for preservation purposes.
When a Cannabis seedling has been left to grow for up to 5 weeks under 18/6, the plant will begin to exhibit very small preflowers. Typically these preflowers reveal themselves once flowering is induced, however it is possible to see which sex you have when knowing what to look for.
Pre 98 Genetics
When investing the time and money into a large pheno hunt, it is better to work with regular seeds over-feminized seeds. During this process the male and female plants will need to be separated well before flowering. There will be some impracticalites associated with this method such as wasted hydro system space, use of nutrients, growing medium, dedicated space, and maintenance. Working with a large number of plants to select from will allow you to access the best looking plants, based on height, structure, internodal spacing, aroma, leaf pattern, and overall vigor.
Regular sexed Cannabis seeds represent a breeding line that expresses an equal balance of male and female chromosomes. Working from seed using regulars is an excellent way to grow out large selections of either male or female plants. Knowing which plants belong to which sex, how to identify them early on and understanding the life cycle of a Cannabis plant, will give you the advantage when pheno hunting for an upcoming breeding project.
Working through a bunch of seeds and narrowing down the best female plants to one keeper, will reward you with the ultimate mother plant, and can often soften the blow of paying three figures for a pack of seeds in some cases. If you truly want to find the best of the best, using regular seeds will allow for the most genetic diversity.