making feminized seeds gibberellic acid

How Can I Feminize My Cannabis Seeds?

You may have heard of feminized seeds before, either online or from another grower. This progressive type of seed has become possible thanks to feminization – a fairly new technique for cannabis growers that rose to prominence during the 1990s. Usually, feminized seeds are those that have undergone a chemical process to make them always germinate into female plants. If you’re curious about how to feminize marijuana seeds yourself and are interested in learning more about the process, be sure to check out the following guide.

Why Should I Feminize My Seeds?

Feminized seeds will always sprout into female plants. That’s important, because female plants are the only type of cannabis that will grow buds and create THC. Male plants, in contrast, will pollinate any female plants in their immediate vicinity. Once that happens, the female plant will stop producing THC. As a result, male plants have the potential to ruin an entire garden. Don’t let that happen. Instead, make sure all of your plants are female before they germinate!

Feminized Cannabis Strains

How Does Feminization Work?

The key to feminization lies in a compound called ethylene. It’s a hormone that has several roles in a plant’s life. Notably, ethylene levels determine the sex of a plant. By either reducing the level of ethylene in plant tissues or inhibiting the action of ethylene, you can trick a female plant into turning hermaphrodite and developing pollen – typically a male-only trait. Then, you can use that female pollen to breed with another female plant. The seeds produced by this kind of pairing will be feminized.

How To Make Feminized Seeds With Colloidal Silver

Using colloidal silver is one of the simplest and most reliable ways of making feminized cannabis seeds. It’s also readily available online and at local pharmacies.

Equipment You’ll Need

Making feminized seeds with colloidal silver requires some specialized gear. Necessary equipment includes a power adapter (9-12 volts), electrical wire, distilled water, 99% pure silver, alligator clips, a PPM meter, and some gloves and goggles for safety. You can find pure silver in spools of silver wire or some coins.

The Process

Using colloidal silver for feminizing cannabis plants is essentially a four-step process. After you make the solution, you’ll spray it on a plant, use that plant’s pollen to breed feminized seeds, then collect them.

Make A Colloidal Silver Solution

Set your power adapter to 9-12 volts. Strip both ends of the electrical wire with pliers, scissors or another sharp tool. Affix the alligator clips to one end of each wire (soldering works well for this). Next, connect the wires to the power adapter. Then, attach a piece of silver into the jaw of the alligator clip – but don’t let them touch each other. Fill a glass jar with some of the water and put one clip on opposite sides of the glass. Plug in your adapter and wait 20 minutes. Now, check the PPM of your solution. You want your solution to have a ratio of between 15 and 30 PPM.

Spray Your Plants

Three days prior to switching to a 12/12 light schedule, start spraying your plant with the colloidal silver mixture at least once per day (but preferably three times per day) until you see it begin to develop male pollen sacs. Don’t be shy – make sure you get them nice and wet. You should begin to see changes forming in your plants between five and ten days after you begin spraying. Once you begin to see male pollen sacs, they should fully develop in three or four weeks.

Pollinate The Plants

Next, you’ll need to collect the pollen once it fully develops. Cover the top of your pot with something to collect the pollen. Then, using a watercolor brush or piece of cotton, gently brush the pollen spores over a female plant. Do this to a female plant that’s about two or three weeks into the flower cycle. You can pollinate a single branch of a plant, or even an entire female plant for maximum seeds.

Collect Feminized Seeds

Wait about six weeks to harvest your feminized seeds. You’ll notice the calyxes beneath the buds will be swollen. Seeds will start bursting out of them. Now you can collect your feminized seeds. Once you do so, you don’t need to wait before planting them – they’ll be ready to go immediately!

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How To Feminize Seeds With Gibberellic Acid

If you’re interested in how to make feminized seeds without using colloidal silver, gibberellic acid offers an alternative. This is a plant hormone you can use for sexing cannabis seeds in a similar process to colloidal silver.

Equipment You’ll Need

To create a feminized seed spray with gibberellic acid, you’ll need even less equipment than you do with colloidal silver. First, you’ll need gibberellic acid. You can find this relatively cheaply online for about $15. You’ll also need a PPM meter, a glass container and water. Of course, never forget about safety – gloves and goggles are still essential.

The Process

To make feminized seeds using gibberellic acid, you’ll need to make a solution, spray it on your plants, pollinate another plant and collect the seeds.

How To Make A Gibberellic Acid Solution

Add the gibberellic acid into water and mix it thoroughly until your solution reaches about 100 PPM. Use your PPM meter to keep an eye on the concentration of your solution. If you add too much acid, you can dilute it with water. Once your solution is ready, pour it into a spray bottle to prepare for the next step.

Start Spraying Your Plants

Once your gibberellic acid solution is ready, spray it over one branch of a female cannabis plant. You’ll need to do this daily for a week or more right after you flip your plant from veg into flower. One side-effect of using this technique is that your plant may experience noticeable stretching. If this happens, don’t be surprised. Keep spraying your plant until you see it start to form pollen sacs.

Pollinate The Plants

Once your plant starts to develop male sexual organs, collect the pollen using the same techniques as when applying colloidal silver. Then, using a paintbrush or similar tool, cover the branch of another plant with the pollen. Again, you’ll want to pollenate a female plant that’s two or three weeks into its flower cycle.

Collect Feminized Seeds

Once your pollinated plant begins to develop seeds from its calyx, you can collect them. These seeds will be feminized and ready to plant. If you’re interested in learning about how to feminize weed seeds, this is one of the safest, easiest and most effective ways of doing so.

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How To Feminize Cannabis Seeds Using Rodelization

Colloidal silver and gibberellic acid are both scientific ways to get feminized seeds. However, if you’re wondering how to sex marijuana seeds without chemicals, rodelization is a natural, albeit unreliable way to do it.

Equipment You’ll Need

This is the most natural way to make feminized seeds. As a result, you basically just need the plants themselves.

The Process: How To Produce Feminized Seeds Using Rodelization

Once a female plant gets too old without being pollinated, as a result of experiencing stress, it will try to do so itself as a last-ditch attempt to protect its genetic line. By inducing stress on a female flowering plant, you can therefore make it develop its own male pollen sacs.

Make Plants Flower

Once your plant is mature enough to flower, switch it from vegetation to flowering by changing your number of light hours from 18 to 12. Then, your plant will start producing buds. Let your plant flower for another seven or eight weeks, making sure to take good care of it the entire time. You don’t want to stress it out too early – if you do, it will just herm instead of growing pollen sacs.

Induce Stress

After your plant’s normal flower cycle is over, let it continue to mature for another few weeks – that’s when it gets stressful for cannabis. There’s no guarantee that rodelization will work, but if it does, you’ll start to see male flowers developing on your plants. These will look like little bulbs – different from the fluffy buds of healthy female cannabis plants. Once these begin to develop, keep waiting and taking care of the plant.

Collect Feminized Seeds

If you’re lucky, after a few more weeks, your plant will pollenate itself. As a result, the seeds that the plant develops will be feminized. This method usually results in fewer seeds than other feminization techniques.

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Remember – Safety First!

While it might sound like a fun science experiment to feminize weed seeds, remember how dangerous working with chemicals can be. Whenever you’re working with chemicals like colloidal silver and gibberellic acid, safety is your number one priority. Make sure you use gloves and goggles whenever you’re handling these chemicals. In addition, never smoke a plant if you’ve sprayed it with either of these compounds. It might be tempting, but you absolutely don’t want to inhale the chemicals!

Ready, Set, Feminize

Together we learned how feminized seeds are made, and, as you can see, there’s no need to be intimidated about how to make female seeds yourself. Now that you finally know how to get feminized seeds from marijuana plants, you can try these techniques out in your own garden. Follow our simple instructions, and you’ll be able to germinate 100% female plants from every seed of your own!

Usually, you can easily buy feminized seeds, but some seedbanks produce regular seeds only or you just don't have feminized seeds right now. If you’re curious about the chemical process that makes seeds always germinate into female plants, here are 3 effective ways to do that.

How are feminized seeds made?

Image of a purple seed emerging from many others in black and white

Feminized seeds were a revolution when they came on the market more than 15 years ago. Nowadays they represent more than 75% of the worldwide sales of marijuana seeds, and this is no coincidence, as during this time they have proven to be just as good, or even better, than regular seeds. In this article we will see different ways to create 100% feminine seeds, are you in?👉

🔥 Is it easy to create feminized marijuana seeds?

If you have ever wondered how to feminize a cannabis seed and you imagined it was a difficult task I’ll tell you it wasn’t, creating a good regular variety can be as complicated as producing female cannabis seeds, because the greatest difficulty is in finding parents who transmit their best qualities to the offspring.

If you have already accomplished this step and your only concern is to know how to extract feminized seeds from a cannabis plant, I am going to explain it to you briefly.✍

Image where you can see the thin pollen produced by a reversed plant falling on female cannabis flowers*

🎯 How to make feminized seeds with STS step by step

  1. Prepare STS (Silver Thiosulphate), mixing silver nitrate with sodium sulphate.
  2. Spray the STS on the plants that we want to reverse their sex, these will act as “male” in pollination.
  3. Change the photoperiod to flowering and repeat the spray application of STS one week later and again 15 days after the first time.
  4. After the third application change the photoperiod of the receptors that will act as female during pollination, this will be the last application of STS, after the second one we already inhibit the production of ethylene, which causes the plant to flower as male instead of female.
  5. About 25 days after putting the receptors in bloom they will begin to be at their best to be pollinated, depending on the variety, this will happen at the time when the reversed ones start to release pollen.
  6. Pollinate for 2 or 3 weeks if you want to get a lot of seeds, if you want to get few and take advantage of the rest of buds to consume you can do a located pollination on a single branch.
  7. After the last pollen intake by the females it is time to ripen the feminized seeds, it is very simple, we only have to feed the plants for 30 days more as when we cultivate to produce flowers.

Requirements for parental selection

The females chosen to be reverted to male have to undergo a number of tests to prove that they are suitable for reversion. These tests are based on the resistance and sexual purity of the selected specimens and basically they try to induce different types of stress. Only plants that stay fully female will pass the test and then they can be considered good breeding tools.

When we choose the varieties we want to cross we have to look at the desirable qualities, such as taste, production, effect, speed, and so on. But it must be clear that these features are only useful if they are transmitted to the progeny, a good phenotype is only a good phenotype if its qualities are not transferred to its descendants. On the other hand, if it transmits those qualities, it can also be considered a good breeding tool.

Photograph of a hermaphrodite marijuana bud where you can see both male and female flowers*

🧐 Are there other ways to produce feminized cannabis seeds?

Yes, there are, although not as effective and reliable as with STS, so we do not recommend them. But if you want to know other ways to make 100% feminine seeds of your favorite weed I’ll tell you. First of all you have to understand that all techniques are based on stressing a female plant to revert its sex to male, so it can produce flowers with which it can pollinate another female.

The first feminized seeds on the market were made by naturally stressing a female to pull out male flowers with pollen. This is not a good method, since plants that revert under natural stress can easily transmit this trait to their offspring. It often happened that those feminized strains were hermaphrodites, so natural stress is not a good way to reverse cannabis females.

The most common technique used to cause stress to female plants was known as “Light Poisoningor light stress. It’s easy, you just have to use irregular photoperiods, or often interrupt the night cycle of female cannabis plants during flowering.

⚠️ What is Rodelization?

It is another stress process, in this case due to over-ripe, i.e. not harvesting in time or lengthening the flowering cycle of a female cannabis plant to produce male flowers. This method is not very good because of the small amount of pollen that is created, it is not worth it if you want to make many feminized seeds.

This is something they do naturally as a way of perpetuating the species. When a female guesses she’s going to die and hasn’t been pollinated, she spontaneously generates fertile male flowers to self-pollinate and continue with the lineage.

⛳ Making feminized seeds with colloidal silver

The technique for producing feminized marijuana seeds with colloidal silver is based on the same theory as the STS one. Both use silver to inhibit the production of ethylene in a female plant, and that this specimen blooms as a male and releases pollen.

With colloidal silver there are also several spray applications during the night cycle in some of the first days of the flowering cycle. The silver used in this method, or in the STS technique, is a heavy metal that can be toxic. It is therefore important to cover the substrate so that possible droplets from the sprayed leaves do not wet the soil.

👌 How are feminized seeds made with gibberellic acid?

This way of producing 100% feminine seeds with gibberellic acid was published by the great Robert Connell Clarke in his magnificent book “Marijuana Botany”. With this method several applications must be done during a period of 5 or 7 days. The biggest problem with gibberellic acid technique is its instability, since a very precise dose is needed to be effective, around 100 PPM. It is also common that each variety may need a different dose, so not many people use it nowadays.

👾 Conclusions

If you want to make your own feminized seeds, I recommend you the STS method, it is the most used for some reason. You have to be careful not to inhale the gases it produces, protecting yourself with a mask, safety goggles and gloves for its manipulation, but it is the most effective technique. It is surprising to see an elite clone bloom as a male after having grown it many times as a female, I invite you to try it.

If you liked this article you can help us if you share it, that way if a friend of yours is curious about how to get feminized seeds he/she can see it here.🤪

Do you want to know the best way to produce feminized cannabis seeds? ✨ In this article we will show you ❤️ See how easy you can create your 100% feminine.