Many gardeners have a collection of seed packets that contain seeds that didn’t make it into the garden in years past. Before purchasing more seed, check the stock of any seed still on hand from past seasons. Even when stored properly in a cool, dry location, seed longevity varies by species. Corn, lettuce, onion, impatiens, and pansy seeds, for instance, can be short-lived, losing viability after one or two years. Even though some of the seeds may still germinate, the germination rate declines, decreasing the likelihood of healthy seedling vigor. An easy test can be performed to see if the seed will still germinate.
To test germination, place 10 seeds between two moist paper towels or a folded moist towel, insert them into a plastic bag, and place the bag in a warm, dark location. Check every other day for signs of germination. Most vegetable and annual seeds will germinate within 7 to 10 days. If the germination rate is 70% or less, consider replacing that packet for the upcoming growing season. Keep in mind that some seeds require light to germinate and will need to be placed on top of a moist towel in a plastic bag in a bright location. Consult the packet instructions to determine if any light is required; for example, the packet will sometimes state, “do not cover seeds.”
Starting the season with good quality seeds will ensure the best return for your efforts. If you find yourself with more seed than you need, consider swapping them with friends and neighbors or donating to the local Master Gardener organization, a local school, or community garden.