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how to feminize marijuana seeds

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.

Feminized Seeds: What they are and the top methods used to produce them

Feminized seeds produce only female plants, and when they germinate there will be few males among them if they are produced correctly. The threat of accidentally pollinating crops by misidentifying a male is minimized. A male-free crop is only one reason to use all-female seeds: another might be the preservation of a particular characteristic or plant type.

Close up: Female calyx.

The predominant way to preserve the exact genetics of a plant is by cloning. However, a plant crossed with itself produces seeds that retain its parent’s favorable characteristics. Another reason to use this technique is to create a hybrid of two female plants. If a branch of one female is turned “male,” there will be pollen to fertilize the other plant, and to create seed when no male is around. Feminized seeds are produced by inducing a normal female, not a hermaphrodite, to grow male flowers with viable pollen.

Close up: Female.

The pollen contains only female, or X, chromosomes because the plant has no Y, or male, chromosomes. The progeny will inherit an X from the male flower’s pollen and an X from the egg donor female flower. The resulting seeds can only inherit two X chromosomes, which means that almost all the resulting seeds will be girls! Congratulations!

Close up: Early male buds.

Feminized seeds are not as mysterious or weird as they might seem

In mature human females, taking male hormones causes masculinizing changes such as breast shrinkage, muscle bulking, and a lowering in voice pitch. The primary sex organs have already been formed, but they shrink.

A similar thing happens when female plants are treated with masculinizing chemicals. The difference is that while a mature human has already formed her sex organs, every time a plant produces a new flower, it is growing a new sex organ. Plants under chemical influence grow viable male flowers, even though the plant is still a female with two X chromosomes, the pollen has only female chromosomes.

There are several methods used to produce feminized seed

By far, the noted breeder Soma developed the easiest method. He noticed that when colas of many varieties reached late ripeness (which, by the way, I prefer as the harvest-time) a few viable male flowers appear. This is also a sign that the buds are ripe. Harvest the pollen using a fresh watercolor brush and brush it directly on the flowers or store it in a small glass or metal container. Not all varieties produce male flowers at the end of ripeness, but many do, and they do it reliably. Very small amounts of pollen are produced using this method, but a little pollen applied properly goes a long way.

Hermaphrodite cannabis plant.

Some varieties flower normally outdoors but experience indoor growing conditions as stressful and produce hermaphrodite flowers. The pollen from these male flowers can be used for breeding, provided that the resulting plants are going to be grown outdoors, where they won’t exhibit the unwanted hermaphroditism. Plant stresses such as irregular light cycles and heat sometimes induce hermaphroditism. However, stress techniques are not reliable. They only seem to work when you don’t want them to, and I haven’t found a stress regimen that ensures masculinization. Should this happen accidentally in a garden with a valuable variety, be opportunistic and collect the pollen, even if you have no plans to use it.

Laboratories and commercial seed producers use three chemicals to induce male flowers in female plants: gibberellic acid, silver nitrate, and silver thiosulfate

Spraying commercial spray on a group of plants.

They each inhibit the plant’s production of ethylene, a hormone that promotes female flowering. Without ethylene, female flower production is reduced or stopped. The actions of these chemicals are localized. If only one branch of a plant is sprayed, that branch will be the only one affected. The rest of the plant will continue growing female flowers, not males.

Close up: Male flower.

Gibberellins are hormones that plants produce to regulate many phases of their growth. Several of the gibberellins, such as GA3, 4, 5 and 7, induce male flowers when they are sprayed on female plants before they begin flowering. GA3, which is the gibberellin most commonly available commercially, is the most effective. For best results, use a solution of 0.01% (0.1 gram GA3 in a liter of distilled water). Gibberellin must be used carefully. Lower doses result in fewer male flowers. Higher amounts have an inhibitory effect. Lightly spray the tops of the plant for five consecutive days and then force the plants to flower by increasing the uninterrupted dark period to 12 hours a day. The sprayed area will stretch a bit, but within two weeks, the first signs of male flowers will appear. They will be ripe and ready to release pollen in another two weeks.

Male cannabis flower.

Silver thiosulfate is more effective than silver nitrate; that is, it induces more male flowers. Sometimes the two chemicals are used together. Spray the plant until the liquid drips off the leaves. Then immediately change the light regimen from vegetative to flowering. The leaves will droop and stop growing for a few days, yellow a bit and then regain turgidity. Male flower growth will become apparent in a couple of weeks. The flowers will ripen a few weeks later.

Silver thiosulfate is made by combining two water solutions, one containing silver nitrate and the other, sodium thiosulfate. Silver nitrate alone can also be used to induce male flowers. Spray a solution of 0.02- 0.03% on the plant, and then turn the lights to a 12-hour flowering cycle. The leaves will droop for a day or so and then resume turgidity. Male flower growth will become apparent in a couple of weeks and ripen a few weeks later. To make a 0.02% solution, add 0.1 gram of silver nitrate in 0.5 liters of dis- tilled water.

Because of market demand, almost all the seed companies offer most of their popular varieties as feminized seed. They are the best choice for most gardeners. The exception is gardeners interested in breeding.

Feminized seeds are not as mysterious or weird as they might seem.