As we were harvesting vegetables for the Seed to Feed program this week, a couple of volunteers asked a great question concerning seed shelf life and storage. This is a timely topic for many gardeners looking to wrap up warm season vegetable production. We are, after all, about six weeks from the average first frost for this part of Indiana. Depressing, eh? Not for me! I am soooo looking forward to fall weather.
Back to the topic at hand; let us first discuss seed shelf life. There is a lot of information out there in the wide world of webs, but a very general rule of thumb for seeds relates to size and hardness. The larger the seed, the longer the shelf life. Seeds can survive once cut off from the plant based on how much metabolite reserves, such as starches, they have available. The larger the seed, the more storage capacity. Also, a harder seed coat often translates to greater longevity. Hard seed coats protect seeds from desiccation, and they can be less susceptible to pathogen attacks.
Now as to storage, most vegetable and annual seeds are best stored in a cool, dark, dry environment. I keep all my personal seeds at home in a paper bag in my basement, to be honest, without any additional special treatment, and am satisfied with seed viability. I like to switch what I grow a lot, so I may not use the same variety for more than a couple of years in a row any ways.
I hope this has planted a seed of thought of what one must do in the coming months as we look forward to ice crystals arriving to a plot of ground near you.
Josh Steffen, Horticulture and Facilities Manager