The Importance of Collecting and Harvesting Cannabis Seeds

There was a time in our not-too-recent history when a sack of weed almost always included seeds. However, as cannabis cultivation evolved, so did the demand for sensimilla, or high-quality, seedless cannabis. Breeders not only began developing their own customized strains, they also started specializing in the cultivation of very special cannabis seeds. These seeds are used in both the breeding process and the wide-spread distribution of the carefully created strain itself.

The process of breeding the perfect strain requires a controlled production of seeds. Breeders must force their favorite plants to produce pollen and then use it to pollinate other favorite strains, thus creating “cross-breeds” of their two selected parents. Note that this process is not haphazard like the seeds one might find in a poorly-controlled outside marijuana grow – cannabis seed cultivation is a precise process that requires controlled, sanitary environments that are thoroughly sealed to prevent outside dander from getting in. 

Males produce pollen sacks which will get carried off into the air to pollinate females.

The plants can “veg” here, or continue their vegetative growth phase if trying to increase their size before seed production begins, but it’s not necessary. Once the plants are large enough, they are put into a flowering light cycle of 12 hours light and 12 hours of complete darkness.

Within a few weeks, the male will produce pollen sacks which will soon burst and get carried off into the air to pollinate the females. The females will now produce seeds which may continue to be used in the breeding process or harvested and sold to the public.

For the purpose of seed production, only around 20 females are recommended per male. However, a single male can realistically pollinate hundreds of females, hence the importance of a tightly sealed environment during the seed production process.

Cannabis is an amazingly resilient plant and doesn’t require male pollination to produce seeds. Evolution has bestowed upon the cannabis plant an amazing ability to self-pollinate when there are no males around to do it for her. Whether stressed or old (for example, a female cannabis plant that is not harvested before her prime), if a female senses an environment that is not conducive to long-term growth, she will produce seeds in hopes that her legacy will continue.

This is how feminized cannabis seeds are produced. Breeders will carefully stress a healthy female plant to “trick” her into thinking her life or safety is in danger.

One common method is to stress the female by applying solutions like colloidal silver or silver nitrate generously onto the leaves when she first enters the flower light cycle. Within 3-4 weeks, male sex organs will appear on the nodes of the female plant. Please note, applying these stress-inducing solutions to plants renders them unsmokable. The particulate cannot be washed off thoroughly because it settles deep into the surface of the plant. This method is for seed production only.

Another method is to simply let a healthy female age. If she grows past maturation, she will produce male “banana” pollen sacks without any male chromosomes. Though she may look like a hermaphroditic plant at this point (one containing the chromosomes of both male and female), the pollen she produces will contain only XX chromosomes and therefore cannot pass the Y (male) chromosome down to its heirs. Pollen collected in this way is then used to pollinate another female which will then produce female-only seeds.

Though many grow ops aim to do away with seeds to grow fine sensimilla instead, sometimes breeders want seeds. Whether to grow their own crops or to sell to a demanding public, cannabis seed cultivators have their goals set on producing healthy, happy seeds in lieu of big, beautiful buds. 

Seed crops are harvested when the seeds are plump and dark, often with a tiger stripe appearance (around six to eight weeks into flowering).

Breeders have begun specializing in the cultivation of cannabis seeds.

After harvesting, the bud is dried and the seeds are collected. Small-scale seed collection is done by simply crumbling the cannabis flower and collecting the seeds that fall out (this video by Johnnys Green Extractions offers a clever way to separate seeds from flower using an old vinyl record cover).

Commercial seed collection usually involves special machines that crush dried flower then pass the trim and seeds into separate bins. After seeds are collected, they’re stored in opaque, air-tight containers to prevent them from rotting or sprouting prematurely.

Though cannabis flower is usually cultivated to be seedless, sometimes the seeds are the whole point. Breeders pay special attention to the pollination, harvest time, and drying process when growing cannabis specifically for the seeds to improve the likelihood of a successful harvest.

How are Feminized Seeds Made?

Feminized seeds are made by inducing a female plant to produce seeds without being pollinated by a male. These resulting seeds will not contain a male Y chromosome, only retaining the two X chromosomes from the female plant, and thus all of the resulting seeds will be female. This process can be done by stressing the plant, altering it with chemicals, or allowing it to grow past its harvesting time.

How Many Plants Can a Male Cannabis Plant Pollinate?

For professional production, it is recommended to pollinate about 20 female plants per male plant, but this is done to ensure tight oversight and quality control. In the wild, a single male plant can pollinate hundreds of female cannabis plants.

Can You Smoke Cannabis That Has Been Treated with Colloidal Silver?

No, colloidal silver is only used on plants raised for seeding purposes, it makes the plants that it is sprayed on unsmokable.

How are Strains Crossbred?

Cannabis breeders create crossbreeds by using the pollen of one strain to pollenate seeds with another strain. The resulting seeds will have genetics from both parents. These new plants are selected by their desirable traits and then stabilized through further breeding, typically using the genetics of their parent strains.

Have you ever harvested cannabis seeds? Share your experiences in the comments below!