Feminized seeds have increased in demand since medical cannabis became legal, but how are seeds feminized? We provide a feminized seeds definition and talk about them in more detail so that you know how to grow feminized seeds for the best results
Ultimate guide: What are feminized cannabis seeds, why they are in high demand and three ways you can make them, too
Feminized seeds have increased in demand since medical cannabis became legal, but how are seeds feminized?
Breeders and seed producers will want feminized seeds for business purposes, as they’re in very high demand in places where growing weed is legal. Photo by iStock / Getty Images Plus
Most people already know that cannabis buds used today come from female plants. Male plants pollinate female plants, which respond by producing seeds. Just like children, some seeds end up being female and some male.
A male plant can pollinate an entire room of female plants. With little more than a bit of wind, each female plant will end up being fertilized. Getting only feminized cannabis seeds is more complicated, and while not an impossible task, this does demand a workaround on the rules set up by nature.
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Why are seeds feminized?
Cannabis growers need seeds that are guaranteed to grow into female plants in order to avoid pollinating the entire crop. Since no one wants seeds in their weed, feminized seeds are required. When it’s confirmed all seeds are feminized, big crops can be grown knowing that the plants are safe from pollination by a male plant.
As cannabis becomes legal in more places around the world, feminized seeds are likely to be among the first things sought out by new growers. Photo by iStock / Getty Images Plus
Breeders and seed producers will also want feminized seeds for business purposes, as they’re in very high demand in places where growing weed is legal. As cannabis becomes legal in more places around the world, feminized seeds are likely to be among the first things sought out by new growers. Reliably producing female plants is of great value in the cannabis industry, because female plants produce flowers that have greater medicinal value.
How to feminize seeds?
When breeding cannabis, growers will intentionally pollinate their females to get certain traits in the offspring. Once the breeder stabilizes a certain trait, the idea is to mass produce the offspring with precisely those traits. This may be done by feminizing seeds that the “mother plant” produces.
In the wild and without any human tampering, cannabis plants produce mostly female seeds when they “perceive” they’re approaching the end of their lifetimes. Feminization is essentially a process of pushing the plant to produce as many female seeds as possible, by making it “think” it’s approaching its last days.
Only a very small percentage of male seeds will be produced because a small number of male plants can pollinate many female plants. This is why the process of pressuring the plant to produce female seeds en masse is called feminization.
In the wild and without any human tampering, cannabis plants produce mostly female seeds when they “perceive” they’re approaching the end of their lifetimes. Photo by iStock / Getty Images Plus
There are several ways to perform seed feminization. Though each approach is different, they all boil down to the same thing—getting female seeds. That said, some methods are more efficient than others and, as such, are preferred by numerous producers and growers.
Feminizing seeds with colloidal silver
Colloidal silver is a substance made from microscopic particles of silver, which are suspended in liquid. Measuring less than 100 nm (nanometres) in size, the particles of silver are invisible to the naked eye. Colloidal silver works by inhibiting female flowering hormones in cannabis. The result of this is that the male hormones dominate, and, thus, male flowers are produced.
By doing so, healthy female plants are transformed into males. The pollen that came off that plant can be used later to pollinate other plants.
After other female plants are pollinated, they will produce feminized seeds. This yields female seeds in large numbers.
Cannabis is known to yield many—hundreds, sometimes even thousands—of seeds after being pollinated. The colloidal silver method is tried and true for consistently getting feminized seeds.
To start the process, spray colloidal silver on the plant branches every three days before switching lights to 12/12 hours, and continue spraying it until the first male flowers begin to appear. As the plant matures, it will produce pollen that should be collected and used to pollinate other female flowers. Collect the new seeds and plant them to get the next generation of the same plant.
Feminizing with gibberellic acid
Feminizing with gibberellic acid may be even simpler than with colloidal silver. Available mostly in powder form and found online, mix the acid with water until it reaches about 100 ppm (parts per million, instructions on packaging will explain), and spray that mixture on the plant once a day for 10 consecutive days during the flowering phase. Male flowers should be produced.
A male plant can pollinate an entire room of female plants. With little more than a bit of wind, each female plant will end up being fertilized. Getting only feminized cannabis seeds is more complicated, and while not an impossible task, this does demand a workaround on the rules set up by nature. Photo by iStock / Getty Images Plus
Once that part of the process is done, apply the pollen from the resulting male flowers on other healthy female plants. The idea is that those plants will yield feminized seeds after being pollinated.
Feminizing with the rodelization method
The rodelization method is, by far, the slowest, least efficient and least reliable approach of the three. Rodelization entails not harvesting flowers after they’ve bloomed, but, rather, forcing the plant to turn male, in order to preserve itself.
After the plant has flowered, it should be left as is for another few weeks. It is likely the plant will then grow a couple of male flowers, in an attempt to pollinate itself once more. If the plant succeeds, the grower will need to wait another few weeks to get decent seeds that are ready for sowing (the method generally yields fewer seeds than the other two).
Feminized Seeds Explained: Let’s Separate Fact from Fiction
What is a feminised weed seed? We try to answer this question and clear some of the misconceptions that even seasoned growers have
Today, feminized seeds are everywhere. You can grow weed for years without actually laying your eyes on anything else. As if marijuana were a single sex (female) plant all along. But it isn’t so, and it’s best to have clear answers to the following questions about feminized seeds: what does it mean and what exactly to expect from them? These questions are not just theoretical, but have a real practical value.
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What is a Feminised Weed Seed Exactly?
Here’s a very short and pragmatic feminized seeds definition for you. Feminized seeds are cannabis seeds that turn into female plants only. This is how they differ from regular seeds which can turn either female or male. Now let’s talk about it in more detail.
As you may know, cannabis has two distinct sexes. Take a bunch of seeds from plants grown in nature and sow them. Some of them will grow into male plants and some — into female plants. The ratio will be around 50/50. Growers call such natural seeds regular.
For some time, regular seeds were all that was available to weed growers. The first small batches of seeds that deserved the name ‘feminized’ started to appear in the beginning of 1990s in Amsterdam. It was the founder of Dutch Passion who first offered them. Today, Dutch Passion is one of the oldest commercial seed banks that are still around.
The feature of this new type of seeds was that they grew into female plants more than 95% of the time. In fact, closer to 100%. It was a God’s gift for bud growers because now they didn’t have to throw away half of their plants at the beginning of the flowering. They knew that there would be only females in their garden and that they would harvest buds from every seed they had sowed.
Are Feminised Seeds Always Female?
Well, ideally they should be, and serious breeders go to great lengths to ensure that ALL their feminized seeds become female, but in reality they never are. Not 100%. Even the best feminized seeds produce males occasionally. Fortunately, such occasions are rare. Statistically speaking, you should grow close to a hundred of plants before you see a male intruder in an all-girl team. So can feminised seeds turn male? Yes, they can, but it’s highly unlikely for you to have this issue with your very first attempt.
What Makes a Feminised Seed?
The feminized seeds definition we’ve given above doesn’t explain how exactly breeders manipulate the beans into producing only females. In a few words, cannabis plants can change their sex in response to stress or when exposed to certain chemicals. It means that females can turn into males and produce pollen sacks instead of flowers.
Growers have long noticed this phenomenon. It’s called hermaphroditism and is a very unwelcome thing in your garden because you want buds without seeds and ‘female’ pollen will make all the buds go to seed and your whole crop will be ruined.
So, growers had been fighting ‘hermies’ for a long time, but they didn’t immediately realize that the seeds that they got in their buds because of female pollen would grow into female plants only. Well, hermaphrodite plants to be exact. Meaning that they will mostly produce female buds, but also some pollen sacks whenever they experience too much stress.
Believe it or not, the very first batches of feminised seeds marketed by Dutch Passion in the early 90s were made exactly this way. The plants were stressed to the point that they hermied and then hermies-prone seeds were harvested and sold. No wonder that those initial barbaric methods gave feminized seeds a bad reputation and still make some purists use only regular beans. You can read more about ‘feminised seeds vs regular’ controversy in a separate post.
Feminized Seeds Without Hermies Are the New Norm
The time when ‘fems’ and ‘hermies’ were practically synonyms is long gone. Now, breeders produce feminised seeds in a totally different way. They use special chemicals for this. It could be gibberellic acid or silver thiosulfate or such a simple solution as colloidal silver water made with the use of a homemade 9V battery feminisation kit. Anyway, none of these techniques involves any stress. It means that the resulting seeds are no more prone to hermies than their regular counterparts.
There is even a special method to make sure that a plant you choose for making feminized seeds isn’t predisposed to hermies at all.
How to Select a Feminized Plant That Won’t Hermie?
It works like this. You take a bunch of regular seeds, grow plants from them, put them into the flowering mode, and when they reveal their sex, discard all males. As for the remaining females, you wait till they begin to flower in earnest and then start to stress them. You can doi it by constantly changing the light cycle: when today it’s 12/12, tomorrow — 18/6, then — 14/10, etc. All weaker genetics—when ‘punished’ this way—will turn hermies at some point. And the ones that stay female despite all the stress are definitely keepers. Meaning they are your best choice for feminized seeds production.
Do Feminized Seeds Produce Different Phenotypes?
Making seeds that always turn female and making seeds that grow into very uniform-looking plants are two completely different things. So, with feminized seeds, a breeder never guarantees that you will get only one pheno. The phenotipic variance can be as huge as with regular seeds. And if you want feminised seeds that don’t have different phenotypes, make sure that the breeder or reviewers describe the strain as stable.
So, we did our best to define feminized seeds’ meaning. Now let’s take a few moments to dispel some misconceptions that people have about this type of marijuana seeds.
Feminized vs Autoflowering
Some people, when they choose a strain, wonder what they should rather buy: feminized seeds or autoflowering. As if these were opposing terms. In fact, they are not. The confusion is understandable: seed shops offer seeds in two large categories:
- feminized autoflowering seeds -> usually shortened to just ‘autoflowering seeds’,
- feminized photoperiod seeds -> usually shortened to just ‘feminized seeds’.
The fact that the words not marked in bold are too often omitted has created this confusion. In fact, there are also regular autoflowering seeds and regular photoperiod seeds, but neither category is very popular. Most newbies don’t even see them when they shop for seeds. All they see are the words ‘feminized’ and ‘autoflowering’, and so they feel like they should choose either one or the other. The good thing is you can have both. Autoflowering feminized seeds produce only girls, and they all start to flower automatically.
This confusion aside, we’ve written a separate post discussing pros and cons of autoflowering vs non autoflowering seeds.
How to Tell Feminized from Non Feminized Seeds
Another misconception is that feminized seeds somehow look different than other types of seeds. Not by a long shot. A seed is a seed. It can be small or large, or it can look mature or immature, but, other than that, you can’t tell anything about the seed’s genetics by just looking at it.
It can be medical cannabis or hemp, sativa or indica, an auto strain or a photoperiod one, it can be a high THC or low THC variety, or CBD rich etc. and all of them will look just the same.
And if you insist on knowing what type of seeds you have—feminized or not—the only sure way is to wait till they flower.
Do Feminised Plants Produce Seeds?
If feminized seeds catch some pollen, they do produce seeds. After all, they are feminized, not castrated. The reason why people have seed-free harvest of buds from feminised seeds is because they don’t have any males in their grow room and no male pollen. But if you get some pollen inside your grow space (from outside or from hermies), your plants will get pollinated, no matter feminized or not. So, if you bought only fems and still your feminised plant has seeds, look for the source of pollen.
How to Grow Feminized Seeds
There is a whole group of questions from novice growers regarding germination and planting of feminised seeds, their grow time and flower time, light cycle, phenotypes and what not.
We’ve already said that feminized seeds look exactly like non-feminized. Well, they also grow the same and should get the same treatment as regular seeds. The only real difference is that you won’t have to cull the males when the plants in your garden show sex.
Maybe there is one more difference. If the breeder hasn’t done his job properly and his fem seeds genetics are unstable, the seeds will be more prone to become hermaphrodites. In this case, take extra care not to stress your feminized plants at any point of their life cycle. Other than that, take care of them just the normal way and you’ll be alright.