Growing dank weed is all about creating dense, resinous flowers rich in THC and other cannabinoids, which requires bringing only female plants to maturity. Some growers pull male plants from their crops during the pre-flowering stage. Others use clones. However, by far the most popular and effective way to guarantee a high yield of tasty buds is to grow cannabis plants from feminized seeds.
What Are Feminized Seeds?
Let’s start with the basics. When you buy cannabis seeds, you can purchase either regular or feminized forms of just about any given strain. Regular seeds have a 50/50 chance of growing into male hemp plants instead of female marijuana plants. Feminized seeds, on the other hand, boast a 99% rate of female plant production, which means you’re all but guaranteed to end up with a full crop of seedless marijuana buds with no pollen-producing hemp plants involved.
Why Use Feminized Seeds?
If you’ve ever grown your own weed, you know that male plants don’t just use up valuable space and resources without contributing to your final yield. They can also jeopardize the rest of your crop. If you don’t pull 100% of the male plants during the pre-flowering phase, they will begin to produce pollen sacs. That pollen can go on to pollinate your female plants, leaving you with seedy, less potent buds.
How to Sex Cannabis Plants Grown From Regular Seeds
Learning how to sex cannabis plants during the pre-flowering phase can be a bit tricky. Male plants usually enter the pre-flowering phase around two weeks before their female counterparts, so you’ll need to pay close attention to the bud sites. Once your plants are getting less than 18 hours of light a day, start looking for greenish-white, egg-shaped pollen sacs. They indicate that a plant is male.
Female plants don’t start to produce buds until around two weeks after male plants form their pollen sacs. The buds start off as cactus-like white growths at the ends of the branches and will continue growing throughout the flowering phase until they become large, sticky flowers.
You need to stay on top of checking your plants during the pre-flowering phase and remove 100% of the males before they can open up their pollen sacs. Otherwise, missing even one male plant can ruin your entire crop.
How to Make Feminized Seeds
If you’re a novice grower, your best bet is always to buy high-quality feminized marijuana seeds from a reputable online seed bank like Kind Seed Co. These seeds are produced by expert plant breeders that are deeply familiar with and experienced in the feminization process. They’ll allow you to grow more plants in a tighter space, avoid pollination, and maximize your yield.
If you’ve already gotten the hang of growing marijuana from feminized seeds, you might be ready to take the next step and start producing your own. The process requires causing one of your beloved female plants to produce male pollen sacs, then using the pollen to pollinate other female plants tagged for seed production.
There are two ways to go about creating feminized seeds: natural rhodelization and chemical inducement of feminized pollen. These days, just about every expert breeder uses the latter method, but we’ll discuss both of them just in case.
Rhodelization: A Natural Method
If you’re the type of grower that prioritizes keeping things all-natural over high yields and ongoing genetic viability, you’ll probably start by learning the rhodelization method. Rhodelization occurs in the wild when a marijuana plant cannot be pollinated and its flowers go beyond the stage of maturation at which you would harvest a domesticated plant by several weeks. At this point, the unpollinated female plant, by mechanisms that we don’t quite understand, will produce pollen sacs in an effort to continue its line through self-pollination.
You can take advantage of the same evolutionary mechanisms in your marijuana garden or grow room. Just pick one plant that you want to use to create pollen and allow it to out-stay its welcome, leaving all of those tempting buds on the branch. Once the female plant produces male pollen sacs, sometimes referred to as “bananas,” you’ll be all set to start collecting feminized pollen.
How to Collect and Use Feminized Pollen
There are as many methods for harvesting pollen as there are for growing marijuana. Most growers employ one or more of these techniques:
- Cover the soil or the top of the pot with a layer of plastic or paper to catch the pollen as it falls.
- Put a perforated clear plastic bag around the entire plant.
- Remove pollen sacs directly prior to maturity.
- Let nature run its course by placing the pollen-producing plant in with the rest of the marijuana crop in an outdoor garden (this is the least desirable method).
Unless you choose to go all-natural and let nature take its course, you’ll need to apply the pollen you’ve collected to the buds directly. You can do so by dipping a soft brush or cotton ball into the pollen then applying it gently to whichever flowers you want to treat, which will allow you to pollinate just one bud and still use the rest of the plant to create tasty sinsemilla. Alternatively, you can also pollinate different branches or entire plants by placing a pollen-filled bag over them and waiting at least 24 hours.
The Problem With Rhodelization
Rhodelization may be an all-natural process, but that doesn’t make it better than the chemical-dependent methods described below. For one thing, it tends to select for plants that naturally herm out, which can negatively impact the genetic viability of future crops. For another, it requires careful attention to timing and inducing flowering in one plant before the rest of the crop since the pollen-producing plant will need several extra weeks to become self-fertile.
Chemical Alternatives
The more professional way to create genetically viable, high-potency feminized seeds involves applying chemical solutions to the parts of your chosen marijuana plant that you want to produce pollen sacs. There are three chemical substances growers use to induce pollen production in female plants:
- Colloidal silver
- Gibberellic acid
- Silver thiosulfate
Colloidal silver is the most popular of these options. It’s got a track record of proven effectiveness and is easy to come by. Technically, you can even make colloidal silver yourself, although most people just buy it online. Regardless of which substance you choose to use, the steps to creating feminized plants via chemical pollen sac inducement are generally the same.
Step One: Isolate a Female Plant
Choose a plant that is definitely female and exclude it from the rest of the crop. You’ll want to keep the colloidal silver or other feminizing chemicals away from any plants you don’t want to use for pollen production, not just because it could create unwanted genetic mash-ups but also because exposure to these chemicals will render fully formed marijuana buds unsafe to smoke.
Step Two: Spray the Bud Sites
You can use a mister or pressure sprayer to target specific bud sites on your chosen plant. These tools are great at ensuring a thorough, even coating of colloidal silver. Treat one bud site or many depending on how much pollen you expect to need. Any buds you don’t treat will turn into ordinary, seed-free marijuana flowers, but remember, you shouldn’t smoke them unless you’re absolutely sure they have not come into contact with the feminizing chemicals.
Step Three: Continue Treatments Daily
Continue treating the same buds at the same time every day until the pollen sacs are ready to open. Make sure you don’t stop spraying early. It’s a common mistake among first-time breeders, but it can lead to substantially decreased pollen production.
Step Four: Collect and Apply the Pollen
You can use any of the methods described above in the section on rhodelization to collect your pollen once the sacs are ready to burst and apply it to your mother plant. The best time to apply the pollen is when the mother is around 2-3 weeks into the flowering stage. All of the treated buds will go on to produce seeds that contain only the female genetics derived from the pollen-producing plant and the pollinated mother.
Step Five: Harvest the Seeds
It typically takes around six weeks for feminized seeds to develop fully. At that point, the plants will likely be nearing the end of their life cycles, so try to keep them alive until the last possible moment. Once the seeds start dropping, they’ll be ready to use. Plant them out right away or store them in an airtight container placed in a cool, dark spot for future use.
It’s Perfectly Fine to Let the Experts Do the Hard Work
If you want to grow feminized seeds but don’t want to go through the hassle of creating them yourself, that’s nothing to be ashamed of. Most professional growers don’t produce their own seeds. They purchase feminized marijuana seeds from reputable seed banks like Kind Seed Co to ensure that 100% of their crop will be true-to-type, and you can do the same.
