how to feminize seeds at home

How to make feminized seeds?

Feminized seeds first entered the cannabis market about 15 years ago. Even if some seed banks were initially reluctant. In the meantime, virtually all of them now sell feminized seeds in their catalogue.

Making feminized seeds isn’t easy at all. We therefore recommend buying high quality feminized marijuana seeds from a reliable source. Yet, if you are dare a devil you can try to make them yourself.

Curious how to feminize seeds? With this guide we tell you exactly how to make feminized seeds at home.

The background of feminized seeds

Most growers use only feminized seeds and some have never even seen a male plant in their lives. Many young cultivators cannot even remember a time when only regular cannabis seeds were available.

Growing weed from seeds was only possible by starting with twice as many plants. To obtain, for example, 10 female plants, it was necessary to plant 20 regular seeds. It was, of course, impossible to predict exactly the number of female plants and there were often good or bad surprises. It was easily possible to end up with no female plants out of a pack of ten!

Cuttings / clones

For growers who had the opportunity, the best solution for growing only females was to obtain cuttings of female plants or to take clones themselves from selected mother plants. However, not all growers can afford to produce their own cuttings. You must have an indoor growing space with specific lighting and the possibility of growing over a long period after selecting one or more mother plants. It is not always easy to make your own cuttings and growers need to know a number of techniques. These are the reasons that led to seed banks producing feminized seeds.

Outdoor growers, in particular, were interested in feminized seeds. Indeed, outdoor growers must keep their plants growing for several months before their sex is revealed, usually during August. In guerilla crops, plants are sometimes difficult to access and it is not always easy to remove the males before pollination. With a culture based on regular seeds, the outdoor grower can end up with a majority of male plants, which can compromise his entire season.

The arrival of feminized seeds, followed by autoflowering feminized seeds, has boosted the sector, making cannabis cultivation easy to access. No more need to recognize males and females and more risk of ending up only with males in its growing space or facing unwanted pollination. Plus you can choose to breed from plants with characteristics that you love.

How to feminize seeds?

As explained above, making your own feminized seeds is pretty difficult but it can be done by changing the sex of the plant which is called “reversion” for which you need a hermaphrodite. The pollen from this plant will fertilize a group of female clones and obtain feminized seeds without having the hermaphrodite traits of a true hermaphrodite plant. We, therefore, speak of “feminization” of seeds but it is above all a question of “masculinizing” a female plant which will act as a reproductive male. Products like GA3 or silver nitrate, therefore, allow the development of male organs and others like phytohormone auxin or ethylene promote the development of female organs.

Products and methods to feminize seeds

Making your own feminized seeds can be done with different methods. The most common methods are:

1. Rodhelization (not recommended)

This is the easiest method to get feminized seeds naturally without any products, but there are many disadvantages to this method. The goal is to stress a female cannabis plant to make it hermaphrodite. This happens from time to time in the wild, usually after the plant is subject to stress such as a lack of water. It naturally produces male pollen flowers and ends up self-pollinating. Changing the photoperiod several times is one of the techniques used to stress the plant and obtain male flowers. Keeping the plant in its growing space at the end of the life cycle, well after maturation, may favour the appearance of flowers. This technique is a bit random and does not always allow good results to be obtained. In fact, you are highly likely to end up with a high proportion of hermie (hermaphrodite) plants in the mix.

2. Gibberellic acid

Gibberellins are a family of phytohormones. Their active compound is called gibberellic acid. Gibberellins are called G or GA and followed by a number from 1 to 110, GA3 being the best known. Long used for growing plants, including cannabis, gibberellin was first identified in 1926 by phytopathologist Eiichi Kurosawa. The chemical structure of gibberellic acid was determined in 1955.

Present in its natural state in plants, it is cultivated in the laboratory in the form of a mushroom and marketed in the form of a GA3 spray. In the cannabis sector, it has several uses. It promotes germination, lifting the dormancy of some old seeds or those that have difficulty germinating. Some use it to obtain larger female flowers, provided that they do not exceed certain dosages. But GA3 is mainly used to reverse female plants. The spray is deposited on cotton which is applied directly to the female flowers of the selected plant, at the beginning or in the middle of flowering. Become a hermaphrodite plant, it will be able to pollinate a group of clones which will then produce only feminized seeds.

Gibberellic acid has long been used to obtain feminized seeds, but most professional seed banks now use silver nitrate, which is considered more effective.

3. Silver nitrate

Silver nitrate is an inorganic compound which has different uses, especially in the health field thanks to its antiseptic properties. It is used for the production of feminized seeds most of the time in combination with sodium thiosulfate to form the STS (Silver Thiosulfate).

4. STS

STS is a mixture of silver nitrate and sodium thiosulfate. This product is mostly used for the production of feminized cannabis seeds. It is possible to buy it ready-made or to prepare it yourself.

5. Colloidal silver

Colloidal silver also allows the reversion of female cannabis plants. It is easily found in online stores and it is possible to prepare it yourself. All you need is colloidal silver with a 9V battery, 2 alligator clips and two silver coins – and a YouTube tutorial to tell you what to do!

Making feminized seeds (step by step)

Once you have colloidal silver or the substance of your choice, the method of preparing the plants is pretty straightforward.

  1. Spray the bud areas of your chosen female plant each day during the initial month of the flowering stage.
  2. As soon as you switch to a 12/12 light schedule, select the bud sites of your selected female plant, and give them a good soaking each day with the colloidal silver, STS or gibberellic acid.
  3. As the treated flowers start to develop, you will notice them forming into male pollen sacs. The bud sites that you don’t treat will develop normally into female flowers but don’t be tempted to harvest them unless you are completely confident that they haven’t been exposed to the colloidal silver during the feminization process as this can be toxic to smoke.
  4. The male pollen sacs can be harvested when they become swollen and begin to open up -like a ripe seed pod. Don’t harvest until you are sure they are ready and keep up the spraying routine or you could risk ending up with empty sac! You can collect the pollen sacs by picking the seed heads and leaving them to dry for a week. At that point, they can be placed in a Ziploc bag and shaken to safely gather all the pollen. The pollen can then be used to fertilise another female plant; ideally, one that is two to three weeks into the flowering phase. You will need a soft-haired paintbrush to apply the pollen carefully to the chosen female plant. Just gently dab the pollen directly onto the bud sites. You are mimicking the actions of a bee or another pollinating insect!
  5. Six weeks later you will be ready to harvest your very own feminized seeds. You can either germinate them straight away or store them in a cool, dry and dark place for up to two years – or possibly even longer although we doubt that you will be able to wait that long! Be a professional grower and label them with details of the strain and the date.

Final thoughts

Some growers are reluctant to try and grow feminized seeds, saying that it doesn’t feel right and is interfering with nature. However, it is a process that occurs naturally – lobelias, for example, only flowers with hermaphrodite and female plants. Male plants encourage genetic diversity – and the leaves of male plants can be used to make excellent hashish so feminization is not a road that is essential to explore. However, there is no strong scientific reason not to only use feminized seeds – at least for a couple of generations. Just make sure you do it the right way so as not to end up with lots of hermaphrodite plants.

Don’t want to take that risk? Buy feminized marijuana seeds at Weedseedsexpress!

Curious how to make feminized seeds? Making feminized seeds is a difficult process but it can be done! How? Check it out!

How to Feminize Seeds

The cannabis industry has evolved more in the last 15 years than it has in the last century. Society has also evolved, allowing cannabis and the idea of weed to slowly make its way into pop culture, with more and more strains available as well as accessories for smoking or consuming cannabis. Nowadays, pretty much anyone can grow cannabis in their own house with all of the necessary equipment to make their own strains. Years ago only a select few had access to such equipment. Today we’re going to show you how to feminize seeds. You won’t need many items to do so, and the ones you do need are easy enough to get.

Like most living creatures, cannabis plants need a male and a female specimen to reproduce; the male pollinates the female plant which causes seeds to grow. The resulting seeds have genes from both the mother and father plants, so it has a 50% possibility of being female or male. This is why you need to find a way to get your seeds by using just female plants, completely getting rid of male genes, which only leaves the possibility for female seeds.

How to Feminize Seeds | Tutorial

Many growers know that if you stress out cannabis plants, they can easily become hermaphoridtes (a plant with both male and female sex organs) which end up creating male flowers that create pollen which then “impregnates” the plant and others around it. The issue with stress-caused hermaphrodite plants is that most of the resulting seeds tend to be hermaphrodites too, so it’s not the best method to use and it also stresses your plants out quite a lot.

In order to turn a female plant male without stressing it out, all you need is some Silver Thiosulfate, also known as STS. If you apply STS to female plants it will modify their ethylene levels, which is the hormone in charge of determining the sex of certain plants. This causes female plants to change sex and turn into males without the disadvantage of male genes.

Silver Thiosulfate

Making your own STS only takes about 15 to 20 minutes and you’ll need two ingredients: Sodium Thiosulfate and Silver Nitrate, both of which can easily be found in any pharmacy and on our webstore. Sodium Thiosulfate is a neutral chemical salt that’s used to reduce side-effects in some cancer treatments and can easily be bought without a prescription.

You can acquire silver nitrate on our webstore, although some people prefer to extract it from other products that contain it, such as Argenpal, a product used to get rid of warts – each one of these little contains a very small amount of Silver Nitrate, so it’s probably better just to buy it directly without the need to spend more money or spend forever trying to extract the Silver Nitrate from the product itself. We stock Panreac Silver Nitrate, which may be a bit more expensive but you’re guaranteed the best quality, and it saves quite a lot of time.

How to Feminize Seeds | Making STS


You’ll need protective material such as gloves, safety glasses and a face mask; STS can be quite toxic when inhaled and it can leave large burns on the skin. Make sure you don’t use any metallic objects when making STS – everything should be plastic, as metal can alter the composition and reduce efficiency.


Do not use metal instruments or tools in this process. The first thing you’ll need to do is grab a plastic cup and pour in 20ml of distilled water. Next, depending on your chosen method, get either 7 Argenpal sticks or 0.35g silver nitrate. If working with Argenplal, dilute the tips delicately in the water (the tip is where the silver nitrate is). Grab another plastic cup and add 30ml distilled water and 1.3g of sodium thiosulfate, mixing it slowly until it’s fully dissolved. Then, mix the contents of both glasses and mix slowly again – make sure to use a plastic spoon, no metal.

The result is 50ml of pure Silver Thiosulfate, much too potent to use on your plants, so you’ll need to water it down a bit. Add your Silver Thiosulfate to 400ml of distilled water, so you’ll have around 450ml of STS. Make sure to shake quite a lot until it’s completely mixed. It’s still much too concentrated to apply straight onto your plants; take 100ml of the mixture you just made and add it to 400ml mor of distilled water. You now have 500ml of a usable STS mixture that’s ready to be used on your plants.


For maximum efficiency you’ll need to use it the same day you make it. If stored in a dark, cool space it can last up to 15 days but each day it’ll be a bit less potent. If you have it for over a week and haven’t used it we recommend making another batch if you want the best possible results.

How to Feminize Seeds | How to use STS

STS is used by spraying it on your plants leaves, making sure that it’s entirely covered and dripping. We recommend taking the plant away from your growing area before beginning the process, or the mixture might end up getting on your other plants too. You’ll need to begin applying it 4 or 5 days after flipping the lights, right before your lights go off. This allows you to spray the plant without worrying about the light burning your plants. After 10 days, you need to respray your plants, using the same process, covering the plant in the mixture and letting it soak in in the dark.

The sprayed plant will begin growing male flowers with pollen with can then be used to pollinate whichever plant you want, causing seeds to appear that have absolutely no male genes in them. You can use the pollinated plant in order to make extracts from its resin; the amount of seeds it’ll produce will render it pretty much useless in as far as smokeable flowers. The plant that you’ve applied the STS to will need to be thrown away, as it’s much too toxic to do anything with and if you consume any of it, even its resin, you could run in to some health issues.

When should you polinate your plants?

In order to efficiently pollinate select plants, we recommend having two completely separate grow rooms or areas to work in. One should be for the plants that you’re planning on switching to male in order to obtain female polen; the other should be specifically for the plants that you plan on pollinating once you’ve reverted the other ones.

When using the pollen that you’ve collected from your reverted plants, you need to make sure that the plant that you plan on using it on is fully ready for it; this can depend on the strain you’re growing. The right time to begin applying feminized pollen is actually right when your plants begin to flow real flowers.

You generally want to use the pollen as fresh as possible on a plant that is fully ready to take it on, or else it simply might not work – it’s kind of like people, in that sense. Certain things need to be just right. To harvest large amounts of high quality seeds, you’re probably better off doing a few tests in order to find out when the right moment is. You can do this by testing it out on the same strain before going big.

How to Feminize Seeds | Make your own strains

When making your own seeds you can combine your favorite strains, resulting in a plant that you’ve created yourself that is 100% feminized. When you combine two strains, you’ll get various phenotypes with varying qualities and structures. It’s important that you use regular seeds to do this, as feminized ones are much too weak and might have issues such as stress and end up becoming hermaphrodites.

In order to stabilize the genes in your resulting plants, you’ll need to select the phenotypes you like the most, meaning that you’ll need to grow quite a lot of the seeds that you get from your feminized plant. Then, take a clone from each plant and set them to flower in order to study their characteristics. Once you’re done, you’ll need to pick two mother plants, revert them and cross them with each other to get a more balanced version. This process is repeated as many times as necessary in order to create a balanced strain that has the characteristics you’re looking for.

Feminizing cannabis seeds is quite the process. You need to be able to keep perfect track and control of the timing when it comes to flowering and pollen yield if you want the best possible results. Take your time, do a few controlled tests and then you can start making large amounts of your own seeds.

Learn how to feminize seeds at home. Use silver thiosulphate to make your very own cannabis hybrids with your favorite strains for the best results.