For a cool environment, store seeds in either the refrigerator or freezer. Seeds need a consistent temperature without fluctuation to remain dormant long-term.
Long-term storage requirements for seeds and pollen are similar. Both require cool, dark, dry, and oxygen-deprived environments for optimal preservation.
Moisture is a death sentence for pollen viability. Because of this, many breeders opt to mix flour into their pollen at a ratio of 4:1 (flour to pollen) when storing it long-term. This additional step will help keep pollen dry for a longer period of time.
The best way to harvest pollen for storage is to remove an entire male flower cluster and place it in a sealed storage container for several days. After the cluster has dried, place it over a micron screen with parchment or wax paper underneath, and give it a light shake. This will allow the pollen to separate from any remaining plant matter and fall through the screen and onto the wax paper.
To collect seeds, it’s important to wait until they are fully mature and ready for harvest. Cannabis with seeds takes longer to mature than cannabis that only produces flower.
Separate or sift seeds over the screen to remove any unwanted plant matter from the seeds themselves. Brush off the seeds—they should be completely free of any remaining plant material such as leaves, stem, or trichomes, as these elements put seeds at a higher risk for contamination and spoilage during long-term storage.
You can expect cannabis seeds that have been sealed and properly stored to last for several years, and in many cases, longer. Seeds may be dormant, but they are still alive. Over enough time, they will lose their viability.
Many people forget this, but it’s true—your cannabis seeds are living organisms. Before they germinate, however, they are in a state of rest (much like some animals when they hibernate). And like all living things, seeds can die. When storing your seeds, you’ll want to give them the optimal conditions to ensure they hold through until you’re ready to germinate and plant them.
For long-term storage, it’s best to keep your seeds in a sealed container inside the fridge. Remember that opening the door of your fridge can actually cause some pretty dramatic temperature shifts. If you happen to have a second fridge that gets used less often than the one in your kitchen, use that one to store your seeds.
YOUR SEEDS ARE ALIVE
Older seeds often have an extra tough outer shell. Gently scratching this shell with some sandpaper can help moisture and warmth enter your seed at the time of germination. Try gently scarring your old cannabis seeds just before soaking to help them sprout.
Cannabis seeds have three main enemies:
Yes, cannabis seeds can be stored in the freezer. The lower the temperature, the slower they decline. However, it’s usually not necessary to freeze your seeds. Meet the conditions we outlined above, and you should be able to preserve your seeds for up to five years and still get a high germination rate.