Marijuana seeds have an indefinite lifespan when kept in an appropriate environment, provided their hard shell protects its embryo containing genetic material for new plant development, while providing reserves of essential nutrients until they’re time to sprout.
Seeds are living organisms, just like anything else. Like all living things, seeds require water, humidity and warmth for survival and development into plants. Proper storage can extend a seed’s longevity but ultimately it comes down to environment – in an ideal world they should be stored somewhere dark and cool out of direct sunlight.
Temperature, air quality and humidity levels all play a factor in how long marijuana seeds live, but three primary ones stand out: extreme temperature fluctuations, air quality problems and the amount of oxygen available to trigger fungal growth that ruins them, while too much moisture causes problems for their viability. High humidity also complicates matters as seeds often struggle to retain water during humid periods.
Exposing seeds to light can trigger them to begin their own germination processes even without all the ideal conditions in place for doing so. This may use up their stored nutrients before it’s necessary, and also make the seeds harder for later planting to germinate successfully.
Stored marijuana seeds should always be placed in an airtight container to preserve them for extended periods. Their original ziplock bag may provide adequate protection; however, for optimal storage practices some growers add food-grade desiccant or uncooked rice as additional protection to ensure their seeds don’t absorb too much moisture during storage.
When assessing whether a seed remains viable, the best way to ascertain this is through its attempt at germination. Healthy and mature seeds typically appear dark brown or black in colour with soft yet flexible textures when rubbed between your fingers, featuring either stripes or spots around their shells and appearing soft when touched between fingers. Seeds too green or white do not make good candidates for germination. Furthermore, many breeders utilize micro-abrasion techniques with sandpaper in order to make more conducive conditions for their success in making them more susceptible for successful germination.
Once seeds are sealed in an airtight container, they should be placed in a cool, dark location – usually a refrigerator is best as its temperature remains consistent without drastic fluctuations like those seen in garage or shed storage units, which could kill off seeds quickly. A fridge also helps protect seeds from opening/closing too frequently that may damage them further while increasing risk of moisture buildup.