- Mature Cannabis Seeds
- Factors Affecting Viability
- Storing Seeds Properly
Mature Cannabis Seeds
The seeds that are ready for germination and storage are ripe or mature seeds. Cannabis seeds that are ripe will be dark brown and will be mottled (streaks of black) whereas immature seeds may range from green, yellow, or white in color and will be relatively smaller with a softer hull. It would not make much sense to store immature seeds as they do not ripen once they are harvested off of a cannabis plant.
Factors Affecting Viability
Seed viability is the measurement of seeds that germinate after storage under suitable conditions. The factors that influence storage are temperature, moisture, light, storage structure, and seed characteristics. In general, growers know to keep their seeds stored in a cool, dark, dry place, but I want to explore various methods of cannabis seed storage that is adequate for most growers. Using a proper method of storage can allow for your cannabis seeds to last for many years. The ideal temperature for seed storage is between 6-8°C (42-46°F) in a sealed container with a relative humidity of <9%. When you have placed your seeds in storage, it’s important to not change their environmental conditions as rapid variations in temperature and humidity can diminish the viability of your cannabis seeds.
Storing Seeds Properly
If you plan on only storing your seeds for a few months, then the cannabis seeds will be fine in a grip-seal bag packed in an airtight container. The container can be stored in a cupboard or drawer until you are ready to germinate the seeds. If you are storing your seeds for long-term storage, then you may want to consider a vacuum-sealed bag or at least adding a food-grade desiccant to a grip-seal bag. Dry rice grains can be a temporary substitute if you don’t have any food-grade desiccants available. Desiccants contain silica gel, a non-toxic product that can absorb up to 40% of its weight in water vapor. Refrigeration is the easiest way to lower the temperature to ideal storage conditions, but the issue with refrigeration is that the temperature and humidity can fluctuate over time. Vacuum-sealed bags are great because they store seeds without oxygen which is necessary for aerobic microbes to survive and cause damage to seeds. In commercial settings, nitrogen flush sealing is an even more viable method for long-term storage of not only seeds, but of cannabis flowers as well. Nitrogen flush sealing is common for many food products found on grocery store shelves.