Garden Tips: Leftover Seeds Best Discarded

Before deciding what new seeds to purchase, check the remains of last season. It may be that some of the left-over seeds are usable but, in many cases, it may be wise to discard them. Seed cost is a small portion of the total gardening expense and effort and we shouldn't waste our time by planting weak or dead seeds. The vigor and viability of seeds left from last season depends partly on how they have been stored. Left-over seeds should be kept in a closed container in a cool, dry place.

Suitable containers are large mouthed canning jars with lids, or large coffee cans with tight plastic lids. If no other cool place is available, these air-tight containers with the packets of seed in them should be stored in the refrigerator. With proper storage, many vegetable seeds will survive more than one year in good condition. A few that have reduced germination is one to two years include onion, parsley, parsnip, and sweet corn.

When seeds have not been properly stored, or if they are older than three seasons, seriously consider discarding them. Germination will usually be reduced. Sometimes we can make up for reduced germination by planting more thickly, but if seeds are weaker than expected, or growing conditions are not ideal after planting, we may have few plants develop and two or more weeks of gardening time is lost. If only a few seeds are left in a packet, discard them. However, this may be difficult to do if a large quantity of seeds remain.

A simple home test may be used to test germination of such seeds. Count out a definite number of each kind of seed and scatter them on a damp paper towel or blotter paper. Keep each kind or variety separated and marked. Slip each damp towel with the seeds on top into a separate plastic bag and tie it shut. Put it in a warm place (about 75 degrees). Check at least every two days to see if seeds germinate and how quickly. Do not use less than 20 seeds or more than 100. If less than 80 percent of the seeds germinate well, discard the remaining seeds.

Note how rapidly the seeds germinate. While 80 percent may sound like good germination, old seeds are sometimes weaker, and therefore slower to germinate. Although these may start growth in the plastic bag, under less favorable conditions outdoors, they may be too weak to ever appear above the soil. When you select new varieties for the garden, look for varieties that offer special qualities such as disease resistance. Disease resistance is being bred into more vegetables, and when it is available it may mean less need for spraying.

Disease resistance may include only some of the possible diseases, but anything is a help. A resistant variety is not totally immune, but is much less likely to be attacked unless growing conditions become unfavorable and weaken the plant in other ways. In selecting seeds, hybrid seeds are often more expensive than non-hybrids. However the extra vigor and quality of hybrids makes up for more than the added cost of the seeds. Always try a few new varieties to compare with old favorites. A garden should never be totally old or totally new, but a combination of dependability and a search for something better.

Accessible Gardening: Tips & Techniques by Joan Woy.