Understanding Plant Gender and Reproduction
An accurate understanding of cannabis plant gender is essential for all growers, not just those who want to propagate their own plants. That’s because there’s a huge difference between male and female cannabis plants. Namely, only female plants produce high-quality, smokable marijuana.
Male cannabis plants are useful in their own right. They produce hemp fibers, which can be used to make everything from biofuel to textiles. However, they have no place in most commercial or hobby marijuana gardens. This article will discuss how to identify these male plants and why it’s so important to remove them before they can pollinate the rest of the crop. We will also discuss what to do about hermaphrodite plants that exhibit traits of both male and female plants.
Cannabis plants are dioecious, which means that under normal circumstances, a single plant will only bare either male or female flowers. Unlike monoecious plants, which are self-reproductive since they bear both male and female flowers, female marijuana plants need to be pollinated by separate male plants to create seeds and reproduce.
As with humans, regular un-feminized cannabis seeds exhibit a 50/50 chance of germinating into male or female plants. Unlike humans, though, a cannabis plant’s gender can be altered by environmental factors. Under certain conditions, a single plant can become hermaphroditic and produce both male and female flowers. Even 35 day autoflower seeds can flip and become “hermie”, so don’t think that high quality seeds negate the importance of keeping the environment consistant for your plants.
Why Reproduction Isn’t Usually Desirable
Unless they’re trying to expand their crop’s genetic pools, growers don’t want their cannabis plants to reproduce. Creating seeds causes marijuana plants to produce less THC, decreasing the quality of grower’s products.
Seedless buds, known by marijuana enthusiasts as sinsemilla, are more potent and have better taste and aroma profiles. They’re more pleasant to smoke and produce better results, which means commercial growers will be able to charge more money for their products and hobby growers will be proud to share their buds with family and friends. Whether its afghan kush seeds or ak47 seeds, when you buy weed seed to grow yourself and smoke who doesn’t want the best possible bud at the end of all their hard work?
What to Expect During Cannabis Reproduction
Whether growers actively choose to allow some of their plants to reproduce in a grow room or garden isolated from their main crops, or they don’t identify male plants in time to pull them out and prevent pollination, the reproduction process will begin soon after the plants reach their sexual maturity. Here’s what to expect:
Male Flower Formation
Male plants begin to produce flowers, or pollen sacs, during the pre-flowering stage. They look like tiny, grape-like balls along the stalk and can be found at each of the plant’s nodes. About a week or two into the flowering stage, these pollen sacs will burst open and pollen will be distributed to nearby females.
Female Flower Formation
Female flowers grow on large clusters of buds called colas. Within each cola, there are many pistils, each of which contains stigmas that look like tiny white hairs. It is these stigmas that interact with male pollen to form seeds.
Female flowers also produce trichomes, which look a little like stigmas but serve a different purpose. Instead of aiding with reproduction, the trichomes produce resin. This resin contains most of the plant’s THC.
Once the male plants release their pollen, it will travel to egg cells located inside the female plant’s pistils via their stigmas. This is where the seeds are formed. Lambs bread strain seeds are formed the same way as any other cannabis strain, science and evolution have found the best way for this “weed” to endure the test of time.
The pollen produced by male cannabis plants remains viable for several days after release. It can also survive on fabric and other surfaces. Cannabis plants, like all plants, want to reproduce.
The pistils on female plants change as the flowering stage progresses. They grow larger when not exposed to pollen until they have fully matured to increase the chances of fertilization. Once the plant has completely matured, the stigmas will die. Thankfully, pistil and stigma maturation takes a while, so growers have a relatively large window of time in which to take down a successful harvest.
Identifying Plant Gender
The only way to ensure a quality crop of sinsemilla is to prevent pollination. That means removing male and hermaphroditic plants before they produce flowers. Unfortunately, identifying the gender of cannabis plants can be tough, especially since male and female plants don’t start developing easily recognizable sex organs until they’re almost ready for pollination.
The Simplest Solution
By far the simplest solution to this problem is to purchase feminized seeds from a reliable seed bank. Feminized seeds are created using a process known as rhodelization in which growers use colloidal silver to induce female plants to produce male flowers. The resulting seeds are all but guaranteed to be female since they have only female genetics. Plus, unlike ordinary seeds, feminized seeds are not prone to developing hermaphroditic qualities, even when subjected to stressful conditions.
Growing clones instead of growing plants from seed ensures that all the plants will be female. Just choose a mother plant that is performing well, take cuttings from the plant, apply rooting solution, and put them in potting soil. After a few days, growers can force flowering by changing to a 12/12 light schedule.
Since clones have the exact same genetics as their host plants, they will have the same gender. There’s still a chance of female clones developing hermaphroditism, but they won’t produce male plants.
Identifying Male Plants the Old Fashioned Way
Growers who don’t want to use feminized seeds or clones for whatever reason can still avoid pollination by carefully checking their crops for male and hermaphrodite plants throughout the vegetative stage. Male plants have thicker stems than female plants and tend to be taller and more robust, but novice growers who don’t yet have an eye for plant gender shouldn’t make the call to pull plants based on these qualities alone. Instead, they should wait until the male plants begin to produce pre-flowers.
Look for Raised Calyxes
As the name implies, pre-flowers precede mature flowers. In male plants, the pre-flowers will come in on a raised calyx, or group of sepals. Female plants do not have raised calyxes. It’s that simple.
Male plants enter the flowering stage between two to four weeks before female plants, so as long as they’re diligent about checking the plants every day, growers shouldn’t have to worry about pollination. There are also a few other ways that growers can easily identify male plants, so those who are new to marijuana cultivation may want to use multiple methods.
Observe Growth Patterns
Female cannabis plants usually exhibit more complex branching patterns as they enter the vegetative stage, while males tend to be taller and less bushy. This method for identifying male plants isn’t foolproof, and it only works with outdoor crops, so don’t start pulling all the tallest plants as soon as they progress from the seedling to the vegetative stage. However, noting the growth pattern of each plant can help to reduce uncertainty later during the pre-flower stage.
Check the Sprouts
There is anecdotal evidence that male plants sprout from the sides of seeds, while female plants sprout from the top or bottom. No scientific studies have been performed to confirm whether this assumption is accurate, but growers who use this technique report a 90% success rate. As with growth patterns, predictions based on sprouting location should be written down and referenced later during the pre-flowering phase to help growers make more informed decisions.
What About Hermaphrodite Plants?
Hermaphrodite marijuana plants, sometimes called “hermies,” exhibit both male and female traits. That means they can pollinate themselves or the rest of the crop. Like male plants, they must be removed prior to the flowering phase if growers want to produce heavy, seedless buds.
Cannabis plants developed the potential for hermaphroditism as a survival mechanism. Otherwise female plants will sometimes change their gender in the absence of male plants or if the growing conditions are not favorable, which, in the wild, would reduce the plant’s chances of reproduction.
Hermies can develop at any point in a plant’s growth cycle. There are a few environmental conditions that can make plants more likely to develop hermaphroditism. They include:
- Problems with the light schedule, or light intensity in indoor grows
- Nutrient deficiencies
- Excessive heat
- pH imbalances
- Insufficient watering
- Poor genetics
- Cloning feminized seeds
How to Deal with Hermies
Plants exhibit different levels of hermaphroditism. Growers can keep hermie plants with mostly female flowers by removing the pollen sacs as they develop. If there are more male flowers than female, it will function as a male plant and pollinate the rest of the crop. If there’s a 50/50 split of male vs. female flowers, the plant may become self-fertile. Remove plants with 50% or more male flowers from the grow area to avoid pollination.
The Bottom Line
Male plants play a valuable role in propagating the species, but unless they plan to get into cannabis reproduction and genetics, growers need to remove them from their marijuana crops. Those who don’t have any experience identifying male plants can purchase clones or feminized seeds, but eventually, all serious growers need to learn how to identify male, female, and hermaphrodite plants. It’s the only way to guarantee a high-quality yield.