December is the time the seed catalogs arrive in force. Personally, I use only two or three companies – those that have interesting varieties, good prices and reliable germination. We all purchase too many seeds; it’s inevitable. A packet of onion or carrot seeds contain more than enough for a season, so it is important to plan how to take care of leftovers.
Seeds are resilient containers of life. Most will last at least two seasons with a little care. The secret is to not provide a suitable environment for sprouting or spoiling. Stored seeds need to be kept dry, cool, and dark, without temperature fluctuations.
Storing Seeds
According to experts, seeds keep best at 8% moisture, drier than most of our homes. If you want seeds to last more than 2 years, set them out in the shade on a hot dry sunny day and then seal them tight in a jar or plastic bag.
Tip: Save packets of silica gel dessicant found in vitamin and other containers and pop them into the bag with the seeds if you are in a damp climate.
Keeping seeds at a constant temperature below 40°F will extend their viability. Seed banks use deep freezers, but I find that I lose my seed packets under all the food. Also, there can be problems with thawing and refreezing if you only want to use a few seeds. A sealed opaque container at the back of a fridge is ideal if you can spare the space. A cool cellar floor is almost as good.
Tip: Divide seed packets. Keep seeds you intend to plant close at hand. Store the rest in the fridge.
Saving Seeds
Saving your own seeds is becoming more important as seeds companies raise prices and decrease selection. When you purchase a packet of seeds, you have potentially acquired a whole gene pool. Niki Hayden, the coordinator of our local gardening groups suggested that each gardener should save the seeds from just a few varieties each year and build up their stock and expertise over time.
Tip: Beans, tomatoes and lettuce make excellent seed selections for beginners.
Choose self-pollinating heirloom varieties that you enjoy; plant different cultivars at a distance from each other. Hybrids or open pollinated varieties have a greater likelihood for cross-pollination or reversion. That means the plant will not breed true to form and you may find yourself with a strange crossbred or mutated version next season!
Tip: Niki has found that, against accepted wisdom, many older hybrid tomatoes will breed true. Try experimenting with your favorite hybrid.
Look for vigorous, healthy vegetables that taste good and produce well. Mentally set a few plants aside and leave them to go to seed. Dry seeds well and place in a paper bag. Do not put them into plastic or a closed container for a month or two. Use the seeds next season or store according to the advice above.
Beans are the easiest seeds to save and they keep well. Tomatoes need a little more care and attention. Pick very ripe, large, healthy looking tomatoes in late August or early September. Squish the seeds into a cup of water and let them sit for at least 24 hours. This allows the soft sac around the seed that prevents germination to ferment and dissolve. Dry the seeds well on a plate (not a paper towel) until there is no stickiness, and pop into labeled paper envelopes.
Tip: Keep 10 seeds out to test for germination
For lettuce or similar salad greens, let about 5 plants go to seed. The seeds are ready when the small flower heads break apart easily. Set a few seeds aside for a germination test and dry the rest.
Tip: In windy gardens, tie a paper bag around the seed head before the seeds are ripe. Break off the dry head into the bag.
Germination Testing
It is essential to check if seed are viable so you do not waste time planting duds. For both stored and saved seeds, test for germination soon enough that you can buy the varieties that miss. Niki Hayden uses a simple germination trial: place the seeds on a damp paper towel and seal in a ziplock bag. Leave the bag in a warm place for a week and check regularly for sprouting. Different varieties sprout at different rates, so consult a gardening book for expected germination times
Tip: Cut around the sprout on the paper towel and plant in a pot for a very early crop.
Once you get the hang of seed saving, you may find yourself specializing in your favorite varieties. Each season as you save and plant, you modify the gene pool somewhat. Eventually you may find yourself with your own cultivar. That is how our ancestors created the wonderful range of heirloom varieties. There is no reason we cannot follow their examples.