Looking through seed catalogs can be exciting for the avid gardener… and dangerous. Too often I have bought flower or other seeds that I just don’t get around to planting. I also like to buy seeds that I always plant in larger than packet size quantities that can last for two, three and four years or more. Many seeds have good longevity and will germinate for several years, although perhaps at increasingly lower rates. One year I got caught with this habit when almost none of the snow peas sprouted.
So how do you know, before you plant them, if those four-year-old snow pea seeds will sprout?
Seed companies conduct germination tests on freshly harvested seed, a germination test, often referred to as a “germ test.” Some stamp the germination rate (expressed as a percentage) on the seed packet, sometimes even with the date of the germ test.
You can easily conduct your own germ test at home. You might be surprised at how long some seeds remain viable. I’ve had 10-year-old okra seeds pass the germ test with flying colors. However, if I would have tested the above-mentioned snow pea seeds, I would have bought new seed. A germ test also can be helpful if you’re collecting seed.
Things you need: a thick paper towel, blotting paper or coffee filter; plastic bag or other clear or translucent air-tight container, like canning jars; a spray bottle for wetting the paper; and seeds.
Moisten the paper towel with the spray bottle until it’s wet, not dripping, simply moist. Large seeds, like peas and okra, require more moisture; you may want to soak them for a few hours first. Place 10 to 25 seeds on the moist paper towel about one inch from the edge.
Fold the paper so that the other end covers the seeds and press lightly.
Fold or roll the paper to hold the seeds in place and place in the container.
Seal the bag or container. Set in a warm but not hot location out of direct sunlight.
Check the seed packet for germination time. Some germinate in days, others take weeks. If germination generally takes more than a week, don’t seal the container, otherwise things get moldy. Don’t let the paper dry out; use the spray bottle to moisten. Routinely check your seeds by removing them from the container and unfolding the paper. Count how many have germinated (you’ll see the little radicle or seed root) and remove those.
Replace the paper and seeds in the container. Repeat until a reasonable period has passed. If less than two thirds of the seeds germinate, sow them more thickly than usual.
If the seed packet says the seeds need light to germinate, do not fold the moistened paper over them. Place the paper and seeds flat on a plate and cover with clear plastic, or lay flat in the bottom of a clear container with a clear lid. Otherwise the directions are the same.
If those 10-year-old okra seeds sprout well, plant them. If the four-year-old peas don’t sprout, then you know not to waste your time.
Text and pictures by EMG Sandra Siebert
Master Gardeners of Douglas County, KS 