jason-crawford

Medically Reviewed by
Jason Crawford

Article Last Updated on January 4, 2023

As a cannabis grower, cultivating healthy and thriving cannabis plants is at the top of your list of priorities. For that, you need to equip your grow room with all the essentials, water your plants adequately, maintain proper humidity, and even invest in a heat source if you live in a colder climate. However, the key step in marijuana cultivation comes after you’ve planted your germinated seeds at the appropriate depth and they’ve gone through the 4 stages of growth.

Identifying the plant sex when growing marijuana plants from regular seeds bought from the seed bank is probably the most important step in cannabis cultivation. This is because the female marijuana plants are the ones that produce the cannabinoid-rich flower, while the male marijuana plants pollinate the female ones in order to produce seeds, among other things. By having both of them in the same room, the males end up pollinating the females, and as a result, the females produce cannabis seeds instead of cannabis flowers, which is not something you’d want as a grower.

So, let’s see how you can figure out whether you’re growing male cannabis plants or female ones.

Cannabis Seeds and Cannabis Plants

Before we get into the main topic, let’s first briefly go over the cannabis growing process, from seeds to plant.

Prior to growing your plant, you’ll need to either purchase cannabis seeds from a marijuana seed bank, or clone your plants from a mother plant. If you go with the first option, around 50% of your seeds will grow into female plants, while the other 50% will grow into male plants, unless you’re buying feminized seeds. After the germination stage, come the seedling, vegetative, and flowering stages, which is when you have your fully grown cannabis plant that’s ready to be harvested.

The marijuana plant is dioecious, so it either produces male or female reproductive organs. The only exception would be the hermaphrodite plants which grow both male and female ones. The female plants grow female flowers and resinous trichomes which are high in the psychoactive cannabinoid THC, while the male plants are high in the sedative cannabinoid CBD. However, if both plants grow in the same space, the male ones will release pollen that will pollinate the females. So, placing both males and females in the same room is not a good idea if you’re cultivating cannabis for its resinous flowers, because you’ll end up with cannabis seeds instead.

When Can You Tell Whether You Are Growing Female Cannabis Plants or Male Cannabis Plants?

As we’ve mentioned above, the cannabis plant goes through 4 growth stages on its way to becoming a fully grown weed plant, during which it needs specific light and nutrient conditions tailored to its specific type of strain (Indica, Sativa, or Hybrid), and type of plant, which can be autoflowering or photoperiod (this will determine the hours of darkness and light your plant will require to start flowering).

  • Germination stage (3-10 days);
  • Seedling stage (2-3 weeks);
  • Vegetative stage (3-16 weeks);
  • Flowering stage (8-11 weeks). 

The earliest telltale signs that will show whether you’re growing a male or a female weed plant will come in the vegetative stage. The male pre-flowers will be distinguishable from female pre-flowers after about six weeks from the germination stage since they will look similar to the fully developed male flowers. If, however, you aren’t able to differentiate the plants during that stage, you’ll need to wait until the flowering stage during which you can clearly tell apart the female from the male reproductive organs and separate your weed plants to prevent pollination. More on how to tell the difference below.

Male vs Female Marijuana Plants

Now, let’s get into the differences between the male and female plants so you can easily distinguish between the two.

Female Plants

The female cannabis plants are the most sought-after cannabis product since they’re the ones that produce resinous cannabis buds which are used for recreational and medicinal purposes. The most important parts of their reproductive system include the bracts and calyxes, which are where the white hairs called pistils (used to tell whether the cannabis plant is ripe enough for harvesting) are located. You can find the reproductive organs on the nodes where the branches and leaves connect to the main stem. 

When a male plant pollinates a female one, the seeds will be the only things found in the calyxes. However, if the plant remains unpollinated, it’ll produce the well-known buds which have high levels of cannabinoids and terpenes. Unpollinated female cannabis plants are called “sinsemilla” or “seedless.”

Male Plants

As we already mentioned, the male marijuana plants are responsible for the pollination process which results in the production of new cannabis seeds inside the female plants. You can find the male reproductive organs (the male pollen sacs) on the nodes where the branches meet the main stem. The pollen sacks are the tiny balls you see hanging from the nodes. Once fully grown, they open up so the anthers (which release pollen) and stamen are revealed. This is how you’ll be certain that you have male plants on hand.

If you’re growing male cannabis plants, you can, of course, try to cultivate some new cannabis strains and make your own cannabis seeds by allowing the male plants to pollinate the female ones. 

However, to prevent the males from pollinating the females, keep them in a separate grow room once the vegetative stage starts.

Hermaphrodite Cannabis Plants

Similar to how people experience health problems when stressed, so do plants when they lack the ideal conditions necessary for them to grow. Stress causes the female cannabis plants to form male reproductive sex organs together with female ones, resulting in hermaphrodites or “hermies,” which form in order to guarantee the survival of the species (since the female plants can self-pollinate).

If you want to prevent hermies from growing, make sure you keep the conditions in the grow room ideal. Maintain optimal temperatures and humidity, hydrate your plants properly, and make sure they have adequate amounts of nutrients. If you do end up with hermies, simply remove the male sex organs by pulling off the pollen sacks. Make sure you inspect the plant afterward to see if you’ve left some pollen sacks behind.

Can You Only Grow Female Plants?

The only way to ensure you’re growing only female plants is to either purchase feminized seeds or clone your weed plants from a mother plant. The former is produced by breeding two female cannabis plants together. One of the plants is chemically induced to grow pollen sacks and since that plant only contains female chromosomes, once it pollinates the other plant, you’ll get all-female seeds. The latter is grown from clones by taking parts of a grown female cannabis plant and planting it in another pot. 

Final Words on Growing Male and Female Cannabis Plants

Knowing how male and female plants differ from each other is essential to every marijuana grower, so let’s summarize. 

While the female plants produce resinous buds, the male ones are used for pollinating the females, as well as for producing textiles for clothes and other products, and as insect and bug repellents.

By knowing how to distinguish between the two, you can prevent accidental pollination, and get the most out of your grow. However, if you do decide to use your male cannabis plants to grow your own seeds, having them in the same room is essential.

A passionate advocate for the benefits of cannabis. Fraser Horton, who has a background in botany and a strong love of nature, has spent years researching how cannabis affects the body and mind. He established Leaf Nation in 2020, where he has devoted himself to educating people about the legalisation of marijuana and its safe and responsible use. Fraser is committed to highlighting cannabis’ potential for improving wellness and working to dispel the stigma associated with its use.

Disclaimer

The information presented on this page is provided as a public service to aid in education and is derived from sources believed to be reliable. Readers are responsible for making their own assessment of the topics discussed here. In no event shall Leaf Nation be held reliable for any injury, loss or damage that could happen if using or abusing drugs.