A good test to see whether the bracts have swollen is to take a pair of tweezers, grab one bract, and open it up. If there is a seed inside, you have a pollinated plant.
Pollination requires the presence of males or intersex (hermaphrodite) plants, which are females that will also produce pollen. The first thing you want to do to keep the risk of pollination low is to remove as many males or “hermies” as as you can. Especially during the first three weeks of flowering, it’s important to frequently check for possible male specimens in your garden.
The typical cannabis grower normally doesn’t have a reason to keep males, and will want to get rid of them as soon as they are spotted. Cannabis breeders, on the other hand, may want to keep males along with their crop of female plants. In such cases, the breeder will normally separate the sexes to avoid any accidental pollination. They may grow females in one tent and males in another. When grown outdoors, such as in a garden, the males are often kept in the most remote corner of their growing area, as far from the females as possible. Even then, because of the wind carrying around the pollen, there is always some risk of accidental pollination.
Spotting male cannabis plants and pollinated females early can save you from investing further time and effort into an entire growing season that will be for naught. Most of the time, the best course of action is to get rid of the males along with your pollinated ladies and just start a new grow.
Obviously, no one wants to smoke seedy weed. When you grow cannabis and learn how to identify male plants and signs of pollination, you can remove these plants to save your remaining females. Likewise, recognising a pollinated female early allows you to start again before it’s too late, rather than finishing a grow that will only result in a poor-quality harvest.
To determine the sex of your cannabis plants, you will have to wait until the pre-flowering stage when plants begin to put their energy into reproduction. Female cannabis plants show their gender signs later than males. At the location where they will soon grow their buds (the nodes between the stalk and the stem), females will show wispy white hairs.
Among the early signs that your female has been pollinated is that her bracts become larger. Bracts are small, leaf-like structures that protect the female’s reproductive parts. These are the sites from which the flowering buds appear. Do not confuse the bracts with calyxes.
There is a good reason why most growers keep male plants away from their ladies: Pollination from males causes the females to develop seeds. As a result, females focus their energy on seed production, rather than on growing you some fine-quality bud. This seedy and unfortunate final product can be avoided by implementing a few basic techniques.
Another indication of pollination can be the colour of her pistil hairs. When a female has been pollinated, the previously white hairs will soon shrivel and become darker.
Learn about the process of pollination and why you should avoid pollination of your female plants at all costs.
One way to harvest your pollen is to gently and carefully remove all the pollen sacs. Let them dry for a week, and then put them in a resealable bag. If you shake the bag the pollen should easily spill out. You may need to cut a few open yourself.
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When your chosen mother is 2-3 weeks into the flowering stage, take a paintbrush and ‘paint’ your feminized pollen on the developing bud sites you want to pollinate. Bud sites are located wherever you can see leaves meet a stem. By 2-3 weeks in the flowering stage, all the bud sites should have tons of wispy white hairs. These are where you want to put your pollen (in the wild, these white hairs are what capture pollen out of the wind).
Pollen spilling onto a nearby leaf
6 Weeks to Harvest Seeds
Only the buds that come in contact with pollen will grow seeds. You can choose to pollinate all of your buds or just a few on the plant.
Example of young cannabis buds that are ready to be pollinated
It usually takes about 6 weeks for your marijuana seeds to fully develop. Some plants are literally dying right as the seeds become ready, so try to keep your plant alive until the seeds start dropping. The seeds can be used right away, or stored in a cool, dry place for a few years (stored in the back of your fridge is great). Don’t forget to label them with the date!
When pollen sacs are cracking and opening up, you’re ready to harvest your pollen!
1.) Collect pollen when sacs crack 2.) Pollinate female 2-3 weeks into flowering stage 3.) Collect seeds ~6 weeks later. Read the article for pics and more info!