Repeated colloidal silver treatments cause repression of the plant’s ethylene, which is the stuff that creates male flowers. Instead, the treated female plant will grow pollen sacks full of FEMALE pollen (XX rather than XY). Then breeders use the female pollen to pollinate female flowers, resulting in the development of all-female seeds.
Like most things in nature, female cannabis plants have a biological drive to reproduce. After the deed has been done, she will sit back and relax. While a pollinated female cannabis plant WILL still develop decent size buds, they are usually lower quality and contain less THC and other desirable cannabinoids. Not to mention, they’ll be full of seeds. When left un-pollinated, a female cannabis plant’s flowers (buds) will continue to swell, develop more trichomes and become increasingly resinous. She is trying to get as sticky and large as possible to catch pollen in the wind. That sweet sinsemilla – aka unfertilized, seed-free cannabis.
Why Sex Cannabis Plants? The Role of Male and Female Plants
Another way to create feminized cannabis seeds is called rodelization. It is a more natural but unreliable method, and less frequently used by breeders. Near the end of a growing season, an un-pollinated female cannabis plant will sometimes produce pollen sacks in a desperate attempt to pollinate herself. That pollen can be used to try to create feminized seeds, but because ethylene hasn’t been repressed, may also result in male seeds.
In order to correctly sex cannabis plants, you’ll need to become familiar with their anatomy in general. Both males and females produce pre-flowers and flowers in the junctions between stems or branches. The very first pre-flowers show up in the crook between the main plant stalk and a fan leaf stem (petiole), usually near the top of the plant. The good news is, the males usually begin to develop and show sooner than females. I guess the idea is that the dudes want to have their pollen ready and waiting for when the ladies join the party?
Until we can tell the sex for sure, we continue to treat the plants equally. We start our seeds in small 4-inch nursery pots. About two weeks after germination, we pot the seedlings up into an approximately two-gallon (trade size) “sexing pot” like these BPA-free nursery pots. This enables everyone to continue to grow in a happy and healthy manner for several more weeks*. Then, once we can surely tell the difference between the male and female cannabis plants, only the ladies move into their forever home – 15 to 25 gallon grow bags full of recycled organic living soil. To learn more about our soil recipe and how we maintain it, see this article.
The traditional way to germinate a seed is to bury it one-quarter inch deep in moist soil and watch it closely for a sprout. A freshly germinated seed has a very fragile root that is easily damaged when the seed is transplanted. This method allows the seed to germinate without root interference.
The float test is a more scientific approach to determining the quality of a seed. The test involves filling a drinking glass with spring or distilled water and placing the seeds inside of it. Allow the seeds to soak for one to two hours before determining quality.
While it is best to identify male marijuana plants by their pollen sacs as soon as possible to avoid accidental pollination, there is another way to determine a plant’s sex. If male and female seeds are planted at the same time, the male plants will grow faster and taller than the female plants. Additionally, male plants have longer stems with fewer leaves, making them look spindly compared to female plants.
Germinate the Seed
Good quality marijuana seeds have a waxy coating around the shell. This is easy to see if the seed is held up to the light because the shell will have a slight sheen.
Another common way to germinate marijuana seeds is by wetting a folded paper towel or cotton pad and placing the seeds inside of it. It is important not to get the paper towel or cotton pad too wet or it could drown the seeds. Growers should check the seeds after a few days to see which have taken root.
When growing marijuana, it is important to identify male plants as early as possible. Just one male plant can pollinate an entire field, so it is critical that male plants are removed before they develop pollen sacs. There are certain signs that a young marijuana plant is male, including the following:
There are several visual indicators that can give a person an idea about the quality of a marijuana seed. Some details are easy to spot while others take a higher level of scrutiny.