Out in the open, pollen may be viable for one or two weeks under normal conditions. However, when frozen and sealed, it can last up to a year and even longer. Pollen is more unstable than seed and even under the most optimal conditions, it isn’t expected to have as long of a shelf life.
When it comes time to use frozen seeds, remove them from their container and let them sit out on a dry surface for several hours. Letting the seeds reach room temperature will help ensure a successful germination.
It’s important to continually practice germination testing to be sure your stored seeds haven’t lost all viability. To test this, periodically plant a seed and document its ability to germinate.
Seed and Pollen Storage
To tell if a seed is mature, take a look at its shape and color. Premature seeds will be small and light in color, taking on a beige hue. Fully mature cannabis seeds are more full in shape and size and have a much darker brown hue, sometimes accented by black tiger stripes.
A female cannabis plant that has received pollen from a male will produce many seeds over the course of its maturation cycle. Upon senescence, when the female plant is fully mature and ready for harvest, its seeds will be ready for stratification and collection.
Deseeding cannabis can be done by hand or machine. This process typically takes place after the plant has been dried for one to two weeks after harvest. This way, seeds will have reached their maximum maturity and plant material will be brittle enough to break apart with minimal effort.
Fresh seeds should have a germination rate close to a 100%, whereas older seeds will see a significant drop off over time in their ability to germinate.
If you meant when to harvest seeds from cross-pollinated Marijuana plants, then the seed will fall from the flower by itself once it is mature and ready to germinate into another Marijuana plant. Usually, as a best practice to harvest Marijuana seeds, some growers wait for the whole flowering cycle to end just as if they were harvesting the flower.
You can also judge the ripeness of the Marijuana by taking a look at the trichomes; or little hairs/crystals on the flowers and surrounding areas of the Marijuana plant. If they are transparent its still too soon, if they are milky white they are ready and if they turn brown they have become over-ripe. It is also advisable to follow the instructions to harvest Marijuana seeds on the packet since most reputable breeders also have a tried and tested flowering time for optimum ripeness, potency and flavour of a Marijuana strain.
After the whole process of germination, growth and flowering, a lot of growers ask themselves when to harvest Marijuana seeds. Usually, the breeders will include a suggested flowering time for each strain, but as a rule of thumb, Indica marijuana plants harvest in 6-8 weeks while Sativa Marijuana plants take 10-12 weeks.
Look for these signs for when to harvest Marijuana seeds
You might find our FAQ Submission How Do I Harvest My Plant? useful
Pollen is usually collected by expert breeders and used to make cannabis seeds or breed unique strains. It can be manually extracted from flowering male plants and stored for well over a year.
In order to pollinate your plant you’ll want to apply your harvested pollen onto the bud sites (usually located where leaves meet the stem of a plant) using a brush. This will cause the buds to develop seeds which can be collected and grown in the future.
HOW TO COLLECT CANNABIS POLLEN FROM MALE PLANTS?
But it’s important to remember that male cannabis plants are just as important as their female counterparts. Male cannabis plants produce pollen like other male plant varieties which germinate female buds to create seeds.
Cannabis seeds develop in the flowers of the female plants after about 4-6 weeks from pollination. You will see the seeds starting to form in and around the pollinated buds.
Whenever storing your pollen, make sure you minimize the chances of any moisture entering the container or bag. A good way to do this is to store your pollen bag inside 1 or 2 other bags (also known as double or triple bagging).