A complete guide on how to identify biological male and biological female Cannabis plants. A discussion on why that is important, and the different methods that are available.
Why should anyone care about the sex of a Cannabis plant?
It is female Cannabis plants that produce the cannabinoid and terpene rich resin that majority of Cannabis cultivators are after. The resin or trichomes is where the medicinal and beneficial cannabinoids are produced. So it makes sense if a cultivator is growing Cannabis for its resin content (as most Cannabis cultivators do) that they will want to ensure that all of their Cannabis plants are female plants. And on top of that, they will also want to ensure that their female Cannabis plants come nowhere near a male plant that could pollinate them. Why? Because when a female Cannabis plant becomes pollinated, and later fertilized, it will convert all its effort into producing seeds which will dramatically reduces the production of cannabinoid and terpenoid-rich resins.
If you are planning on growing Cannabis, you will need to be prepared for this impending biological gender reveal so that you can act fast to ensure that your lovely ladies have the best chance of success. Below we will be going over a few different methods of how to spot male cannabis plants in your garden.
The High Tech Approach: DNA Testing
One way you can test your plants to see if they are male or female is by actually testing the DNA of each plant. This can be done very early in a plant’s life cycle – as early as the first week of growth. There are a variety of laboratories around the United States and abroad that can perform sex testing on Cannabis tissues. This often involves taking a “hole punch” out of a Cannabis leaf or smearing leaves against a plate to collect tissue for analysis. This is then sent to a lab where the DNA will be extracted and analyzed to look for the presence of male or female genetic signatures. This method is great because it allows someone to gain insight into their plants from the moment the first leaves show up, possibly saving the grower a lot of time and resources by removing male plants before they ever have a chance to show signs of their sex. However, this can also be costly – sometimes as much as $10 or more per sample.
The Low-Tech Approach: Visual Inspection
Often the sex organs of a plant will start to reveal themselves sometime between the third and sixth week of growth – so it’s best to carefully inspect each plant often. In order to spot the difference between a male and female Cannabis plant, you first need to be familiar with the basic anatomy of the plant.
Cannabis is considered a dioecious plant, which means that it has distinct male and female plants. When a dioecious plant “flips” to produce both male and female flowers to self-pollinate, it is called hermaphrodism. This usually happens from unstable genetics or when female plants are placed under a lot of stress. Which in a sense tells the plant that it needs to do anything it can to reproduce. Even if it needs to produce its own male flowers to do it. This concept is important because after you have identified and removed any male plants, you still need to keep an eye out in case any female plants start to show signs of hermaphrodism. If a female plant does “flip” it is best to quickly remove the plant from the grow area and cull it.
Now to the heart of the matter – how do you tell by sight if your Cannabis plant is a male or a female? The flowers of a Cannabis plant start growing in several places. First, there are “terminal buds” which grow at the end of the main shoot of the plant. Then there are “axillary buds” which grow within the nodes of each branch. When you are looking for male or female flowers on your plants, be sure to check both the terminal and axillary budding areas.
A male (or staminate) flower looks very different from a female (pistillate) flower. Male flowers start out looking like small buds dangling from a tiny stem called a filament. Then as the flowers age they open up, revealing the pollen producing structures within called anthers. Often Cannabis growers will refer to these anthers as “bananas” because they somewhat resemble the appearance of a bundle of bananas. You should always try to remove male Cannabis plants from the grow area before they open and reveal the anthers. If the anthers are revealed, you can rest assured there is likely pollen floating around in the air and your female plants will be pollinated and fertilized.
In contrast, female Cannabis flowers feature pairs of “hairs” that protrude from each ovary. Botanically speaking, these “hairs” are the fused stigma and style of the flower which help guide pollen into the ovary where, if the plant is lucky, fertilization will take place and a seed will begin forming. If these female flowers can avoid being exposed to pollen, they will swell and produce large amounts of resin, which contain the primary “active ingredients” that most people want from Cannabis. Seedless female Cannabis plants are referred to as “sinsemilla” and are very rare but do exist.
What to do if you find a male Cannabis Plant your Garden
1. First of all – act quickly. Be sure to inspect your plants frequently and try to recognize the male plants as early as possible. Be very careful when removing any male plants as to not release any pollen into the air. If you find that the male flowers have already opened, consider placing a trash bag over the plant before moving it so that any pollen that may be released while you handle the plant will be contained in the bag.
2. Instead of just tossing your males straight into the bin. Here are some fun helpful ways you can reuse your males. Mulch or chop the male plants somewhere far away from the female plants to be used for compost or fermented teas. This will allow to reuse your males as beneficial nutrients and food for your resin rich female plants. Or consume the males yourself by juicing, blending, or cooking with the leaves.
3. If you have ever been interested in plant breeding then your males will be most welcomed. However, please keep in mind especially if you are growing outdoors that cannabis pollen can travel miles. You may accidentally pollinate your neighbors crop or even a local farmer’s crop if you are not careful. The majority of the beneficial compounds in Cannabis are located in the resins of the female plant once again. If the female plants are pollinated these beneficial compounds will be greatly reduced. One must be extremely careful and mindful when breeding. There have been numerous cases in other recreational states where whole entire crops worth hundreds of thousands or even millions of dollars has been lost due to cross pollination. So please be mindful of your neighbors/community and cull your males.