How feminised cannabis seeds are produced

Posted on 3. June 2019

Most people who have bought cannabis seeds, or researched the subject, know that there are both regular and feminised versions.

Regular cannabis seeds germinate into both male and female plants, while feminised seeds germinate exclusively as females (about 99.5%).

The feminised seeds are almost always considerably more expensive than the regular ones. The reason is that it takes extra time to develop these and there is always a high demand for feminised versions of good cannabis strains. But how are feminised cannabis seeds actually made?

There are two main ways to make feminised cannabis seeds.

What they have in common is that a female cannabis plant must be “tricked” into developing male flowers, and then pollinating a female plant (or itself). Thus, when a female plant pollinates another female plant, the genetics are 100% female and its offspring (seeds) become female seeds.

That’s a bit about the theory behind it.

As mentioned above, there are two ways to trick a female plant into developing male flowers/pollen sacs:
– Rodelization – a.k.a. overripening of the top shoots.
– Colloidal silver method

The first method, rodelization, is the more natural way to make feminized seeds, while the colloidal silver method is more reliable and stable, and the one used by professional seed producers.

Rodelization – overripening of the top shoots.

This technique consists of letting the cannabis plant’s top shoots overripen. The plant makes top shoots to attract pollen, but when this fails, it eventually becomes desperate and opts for a last resort – self-pollination. The cannabis bush develops small banana-like growths on the top shoots (which contain pollen) and thereby passes into a hermaphrodite stage. It is also sometimes seen in clones of old mother plants or plants that have been exposed to stressful conditions during the growth and/or flowering period.

The self-pollinated hermaphrodites will develop a modest amount of seeds, all of which will be feminised as their genetics are 100% female.

– Completely natural
– Super simple

– Somewhat unreliable
– Usually does not produce nearly as many seeds as the colloidal silver method.
– Slow and time-consuming

Colloidal silver method

For some reason, female cannabis plants develop feminised seeds if colloidal silver water is sprayed on them regularly at the start of the flowering phase. As with the over-ripening method, it will develop male flowers, and make pollen sacs with 100% female pollen. This pollen can then be used to pollinate other female plants.

This is the method used by seed producers, as it is easy, quick and economical. In contrast to the rodelization/over maturation method, genetics from plants that are particularly prone to develop hermaphroditism are avoided. The genetics are thus completely unaffected and the result is more stable feminised seeds, understood in the sense that they do not easily become hermaphrodites due to stress. This method also produces much more pollen compared to rodelization.

– Stable and reliable
– Large production of seeds

– Requires that you buy colloidal silver or make it yourself.
– You should not use the cannabis plant for anything other than seeds, as ingesting it can be harmful to your health.

Procedure using the colloidal silver method

You need:

– Colloidal silver water (available in some health food stores and online – or you can make it yourself)
– A nebulizer bottle

The female plant is sprayed thoroughly with colloidal silver water from a spray bottle. This is done from day 1 when the 12/12 light cycle starts. The solution must be sufficiently concentrated; at least 30 ppm silver.

The plant is then sprayed daily until it starts to develop pollen sacs. It usually takes about 10-14 days, but some varieties can take up to 21 days.

Once the pollen sacs are formed, they need time to swell and mature. When they are just about to open, they are ready. This is clearly seen by the fact that they start to crack and open. Before they open completely and pollen sprinkles all over, they are carefully removed. Store them in a cool, dry place for about a week, where they are allowed to dry.

The pollen sacs can then be shaken or cut open to release the pollen. The released pollen can be transferred to e.g. a piece of paper and blown over the top shoots. Then the plant will start producing lots of lovely feminised cannabis seeds.


There are two main ways to produce feminised cannabis seeds:

– Rodelization which is a natural over maturation of the plant after which it becomes hermaphroditic and self pollinates resulting in seed production.

– The colloidal silver method, in which colloidal silver water is continuously sprayed at the beginning of the flowering phase, after which the cannabis bite in the affected areas inexplicably switches to seed production.

– The latter is the way all professional seed producers make their feminised cannabis seeds as the method is more stable, high-yielding and efficient.


As mentioned, you shouldn’t consume cannabis buds that have been sprayed with silver water, but some clever growers do this by spraying only the bottom few branches. Thus, the rest of the plant remains untouched, and can therefore subsequently be consumed without risk. Of course, you have to pay attention to where you have sprayed and stay on the safe side by only taking top shoots far from the sprayed branches.