Storing Seeds

Seeds are living things, and need to be properly stored to maintain their viability for as long as possible. If you are like me, seed catalogs are addictive, and it is very easy to get carried away when buying seeds. You might have hundreds of seed packets, and room for approximately 15 to 20 different varieties in your garden. So, how to store the rest of the seeds that you will not be planting this upcoming season?

The most important thing to remember is that you need to protect your seed investment from heat and humidity. More than anything else, too much moisture will hasten the deterioration of your seeds. The ideal moisture level for seed storage is only 10 to 12%, so they need to be stored at a low relative humidity level. Seeds should never be stored in a warm, sunny, or humid environment like a greenhouse, even for a few hours.

The ideal storage medium is a sealed glass jar in the refrigerator. I have stored seeds for 3 or 4 years in the refrigerator in several layers of zip-loc bags, and have had good germination rates. A cool basement might also work well, as long as it is dry. This year, I ordered a lot of seeds (approximately 140 packets), and sealed a large number of them inside wide-mouth Mason jars with my Food Saver vacuum sealer jar attachment. I would not advise vacuum sealing the packets directly, as it could crush the outer seed coating, and ruin the seeds for future planting.

Depending on the seed variety, some seeds have a longer shelf-life than others. These include squash, radishes, turnips, and lettuce. Seeds with a shorter shelf life include onion, spinach, chives, and pumpkins.

If you have had seeds for a long time, you can check their germination rate by placing them between damp paper towels and placing them in plastic bag for a few days (on top of the refrigerator works well, and acts as a gentle “seed-starting” heat mat). If they sprout, they can be planted in the garden, and if they don’t sprout, you haven’t wasted valuable time and space in the garden waiting for them to come up.