I have an indoor growroom and in my recent harvest I found seeds in the buds, but I’m sure there are no male plants in the room. I’ve heard that light leakage can cause plants to become hermaphrodites. Is this true, and if so, do you have any tips for avoiding this?
Cannabis plants are monecious. This means they have the ability to be either male or female. Or in the case of hermaphroditism, they can be both. The reason to make sure there are no males or hermaphrodites in your garden is because male flowers make pollen. When pollen touches the white hairs on a flower, it makes a seed, and seeded weed gives you headaches. Even though there are reasons in nature hermaphroditism could be important, such as continuing the species in case there is no male present, hermaphroditism is generally a bad thing when talking about cannabis plants.
Light poisoning is the most common cause for a normal plant to hermaphrodite.
Light poisoning refers to the flowering night cycle of a plant being unnaturally interrupted with light. The best way to prevent this is to close yourself inside your darkened room during the daylight, and then after allowing a few minutes for your eyes to adjust to the dark, check for any light leaks from covered windows, door jams, etc. Also cover all timer and appliance lights with tape.
Negative stressors can combine with small interruptions of the light cycle to cause hermaphroditism, especially with less-stable, clone-only hybridized strains. When the night cycle is abnormally interrupted, it sends a mixed hormonal signal to the plant. This can cause a full female plant to throw some male flowers. Male flowers are easy to identify, especially when side by side with female flowers. Male flowers look like small bunches of bananas, which will take a week or two to swell before they burst and release their pollen.
Finding a hermaphrodite in your growroom can happen at any stage of the flowering cycle and is indicated by the presence of male flowers growing on the same plant as female flowers. As with all species in nature this can occur in varying degrees. A plant can become slightly or majorly hermaphroditic. In cases where singular male flowers are found between the branch and stalk nodes, you should be diligently removing them as they grow. You must re-inspect the plant top to bottom every few days to be sure pollination and seeding doesn’t occur. If you find male flowers (anthers) actually growing from within the female flowers (buds) the situation is a little more dire. You can still remove all the male anatomy as it appears, but it will be harder to find and much more prevalent. This is a horrible discovery that leads to a tough decision: Should you let the plant live and risk the whole crop being ruined by seeds?
In either case, once hermaphroditism has compromised the safety and purity of your sensimilla, the plant should not be propagated further. Remember, once a hermy, always a hermy. The plant pictured here is in the tenth and what should have been the final week of ripening, but a timer failed and one light stayed on continuously for almost two weeks, causing this vegetative regrowth. Because the light was continuous, the plant made no pollen. This method of re-vegging can be used to save a flowering plant you have no copies of, but be careful, as this may cause some strains to hermaphrodite.
Purposefully causing a plant to hermaphrodite is called selfing. Gibberellic acid or colloidal silver is typically sprayed onto the female plant. This technique is used to make feminized seeds and uses the plant’s ability to be both male and female to force a female plant to produce male flowers. The pollen contained in these male flowers can only produce female seeds. Just keep in mind that feminized plants should not be used for breeding, as they were produced without a true male, making them genetically inferior.
Do Feminized Cannabis Seeds Make Hermies?
What Are Feminized Cannabis Seeds? These seeds all grow up to be female plants. That means every plant produces buds. With “regular” or unfeminized seeds, about half the plants will turn out to be male, which don’t produce buds. They can also pollinate your female plants (causing seedy buds). Therefore most growers will remove male plants from the grow room as soon as they’re identified. Learn more about male vs female plants. Feminized seeds let you plan your grow more effectively because you don’t have to throw half the plants away once they start flowering.
Every plant grown from feminized seeds will produce the buds we know and love. This plant was grown from feminized Swiss Cheese seeds.
What Are Hermies? “Hermie” is short for “hermaphrodite.” Hermie cannabis plants usually look like normal female plants for the most part, but they also grow some male parts that produce pollen. This causes seedy buds just like pollen from male plants. Hermies are to be avoided! Read the full tutorial on hermies.
It’s no good if your “female” plants start growing male flowers or parts of male flowers. That can cause seedy buds just like a male plant!
This bud got completely seeded due to a hermie in the grow space. Notice the lumpy round bits. Those are seeds forming.
What’s the matter with a few seeds?
Cannabis growers are trying to grow sinsemilla (seedless buds). A few seeds won’t hurt anything. But if you have very seedy buds, it significantly lowers your yields because plants are putting all their energy into making seeds. The buds also tend to be less potent if they are full of seeds. Seeds are not the end of the world, but it’s good to avoid if possible.
“Sinsemilla” means “no seeds.” Sinsemilla is the highest quality and most potent of all buds
Since most growers are trying to grow sinsemilla, having only 100% female plants in the flowering grow room is crucial to prevent pollination.
Feminized cannabis seeds can be a blessing for small-scale growers. While male plants produce pollen sacs, feminized seeds ensure all your plants will end up being bud-bearing females (instead of growing half male and half female plants like with regular seeds).
If you don’t have room for extra plants, feminized seeds can make planning your grow a lot easier!
Good feminized seeds should produce only 100% female plants, with no hermies or male plants. So starting with feminized cannabis seeds lets you make the most efficient use of your grow space. You don’t have to worry about identifying male plants and throwing them away before they pollinate your female plants. With good feminized seeds, you know that if you’re growing 10 plants, all 10 of them will make buds, and that makes it easier to plan out your grow ahead of time.
With all these bonuses, why would any small-scale grower use any other type of seeds?
Pros of Feminized Cannabis Seeds
All plants produce buds
You don’t have to throw away half your plants after nurturing them for weeks
You don’t have to worry about your buds getting pollinated, causing seedy buds, reduced bud quality and lower yields
But is there a dark side to feminized cannabis seeds?
One of the biggest worries growers have about feminized seeds is that they will produce hermies instead of 100% female plants as advertised.
This hermie is growing both male and female flowers. Can this be caused by feminized seeds?
Unfortunately, hermies can be a lot easier to miss than a male plant since it may just be a small part of the plant that’s affected. A male plant makes itself known at the beginning of the flowering stage, but a hermie plant may grow only buds except for just one or two tiny pollen sacs. A few yellow hermie bananas hidden in the buds can also produce pollen. Any type of male flower part that grows in your garden can add seeds to your buds, and hermies are some of the worst offenders.
This grower didn’t notice that the buds had been seeded until harvest. As he was trimming, he noticed seeds popping out. Since there were no male plants, chances are this was caused by an unnoticed hermie somewhere in the grow space.
Is it True that Feminized Seeds Sometimes Cause Hermies? Yes!
Many growers believe that feminized seeds can cause hermies, and there is some truth to that. In order to create a feminized seed, one of the parent female plants had to be forced in some way to produce pollen.
That pollen is used to pollinate another female plant, and the offspring of those two plants will all be female since both of the parents were female. That’s how you get feminized cannabis seeds. But that also means every time you have a feminized seed, that seed had a plant that produced male flowers in its recent genetic history.
There are different ways to feminize seeds, but only some methods produce seeds that turn hermie on you.
It’s important to understand that hermies can happen a couple of different ways. And the different types of hermies affect what genes are being passed on to the seeds.
This swollen calyx has a seed developing inside
What Causes Hermies?
Hermies can be caused by many things, including…
bad genetics – the plant comes from a line of plants that naturally create hermies for no reason, even in good growing conditions
high stress – high temperatures, light leaks, inconsistent light schedules, as well as other types of major stress can cause a healthy plant to hermie, though some plants/strains are more susceptible than others
letting buds over-mature – this is also known as “rodelization;” basically when the plant’s buds have gone past maturity without being pollinated (if the grower waits way too long to harvest), a female plant may make male pollen within its buds as a last ditch effort to pollinate itself and make seeds for the next generation
chemical stimulation – by exposing a female plant to certain substances like colloidal silver or gibberellic acid during the early parts of the flowering stage, you can force any female plant to create pollen. This is how seedbanks get female pollen to produce feminized seeds.
Seeds created from “female” pollen will turn out being female (or at least as female as the parents).
The pollen from a hermie plant makes feminized seeds
The pollen sacs on this masculinized female plant have opened and pollen has spilled onto the leaf below
Another type of hermie: a yellow “banana” can appear in your buds and make pollen. This male flower part would normally be inside a pollen sac. When it’s in the open like this, it becomes a little pollen generator.
Feminized seeds are susceptible to becoming hermies themselves when exposed to the same conditions as their female “father” who produced the pollen. But since any plant can be chemically induced to produce pollen, it doesn’t mean that the ability to hermie in a natural environment is passed on to the seeds.
So only some feminized seeds come from parents with bad genetics, and that’s what’s the grower cares about most.
The bagseed gamble… When you find seeds in your buds, that usually means that the buds were pollinated by accident. Seeds that were accidentally created are suspect. It could be that a stray male plant caused them, which means there were no hermies and you will get about half male and half female plants. But accidental seeds could also be the result of herming by an indiscriminate grower, and that means you have feminized seeds, sort of. Some of them may produce pollen on you just like their parents. Growing with bagseed is a big gamble… you never know what you’re going to get.
Are your cannabis bagseeds viable? Viable, good seeds usually appear either dark and striped or solid gray/beige.
If a seed is pure white it usually means it’s underdeveloped and won’t sprout. But it can sometimes be hard to tell. In the end, if a seed sprouts and grows it’s a viable seed! I’ve had very pale, flimsy seeds sprout into gorgeous fast-growing plants, so if you’re not sure the best thing to do is try to germinate it!
Seed Banks & Breeders
Commercial breeders and seed banks use chemical stimulation to create feminized seeds. What that means is they put specific compounds on developing female plants to force them to produce pollen. You can actually do this yourself at home.
This technique works on nearly any female plant, including plants that would never hermie naturally. So it can be used to take two plants with great genetics to produce female seeds. But the same process will also work incredibly well on plants that do hermie easily all on their own. That means it’s up to the breeder to test and make sure that they have a solid plant with unbeatable genetics before using the feminization technique.
The pollen that results from chemical stimulation is used to pollinate another female plant and make feminized seeds. If the parent plants would never hermie without chemical stimulation, then you have created feminized seeds that won’t ever make pollen in your grow room.
But if one of the parent plants was chosen because it does hermie easily, you’ll end up with seeds that likely will herm. The breeder might not have done any testing on the parents or the resulting offspring to even know.
Without testing, a breeder can’t tell whether they’ve created quality feminized seeds
Choosing the Right Cannabis Breeder
Unfortunately, some cannabis seed breeders are more trustworthy than others. The great ones have created stabilized strains that have been bred over several generations to produce a consistent product without any problems with plant sex.
Less scrupulous breeders might breed two random female plants together and sell the resulting seeds as a new strain without any testing. In this second case, you don’t know what to expect, and neither does the breeder.
If the breeder hasn’t tested their strains extensively in many situations, they won’t know whether their seeds tend to hermie or not. If they have carelessly bred plants that have a tendency to herm, then it’s really likely that at least some of the resulting seeds will have the same problem.
Breeder choice is important!
I have to admit I may be biased towards feminized seeds. I’ve grown almost exclusively with feminized seeds over the last decade. It has made my life so much easier! I only purchase seeds from breeders that I trust and all the resulting seeds have been bud-bearing females. I haven’t had any real problems with hermies.
On the flip side, I’ve heard of growers buying feminized seeds from untrustworthy breeders and having a big portion of their seeds turn male or become hermies even in perfect growing conditions. So there is truth to the fact that you can run into hermie problems with feminized seeds.
Yet there are good and bad breeders out there, and with good breeders, you have a very low chance of running into cannabis sex problems.
So if you do choose to purchase feminized seeds (or any seeds really), please make sure you get them from a trusted breeder!
Conclusion: Feminized seeds from a trustworthy breeder have a low chance of producing hermies, but the odds are much worse with feminized seeds from an untrustworthy source
The truth is it takes a hermie of some sort to create feminized seeds. That means that you always run the risk of running into hermies when growing feminized seeds… yet that is true for non-feminized cannabis seeds, too! Lots of regular seeds produce hermies.
What’s most important, whether you get feminized seeds or not, is to get your seeds from a breeder who has a reputation for producing quality genetics. That is the best thing you can do for any strain to ensure a smooth grow. With a great breeder, you have a very low risk of running into any sex or gender problems.
I personally prefer feminized seeds, and that’s the only type of seed I grow. It makes it easier for me in my limited grow space. I haven’t run into any significant problems with hermies, so I’m satisfied with growing only bud-bearing plants.
Yet a lot of growers grow with regular seeds because they’re easier to breed and produce at home. Many growers have created a system for weeding out male plants that is more convenient for them than using feminized seeds.
In the end, when it comes to feminized cannabis seeds you need to decide whether the small chance for hermies is worth the convenience of all-female plants. It’s up to you to figure out what’s best for your needs!