Storing Seeds

You can find good, cheap containers for storing seeds around your house, including old prescription bottles, glass jars with screw-on lids, and plastic film canisters. These containers all protect from outside moisture and pests. If you have some very small packets of seeds, label and store them within a larger container.

Seeds must be kept dry and cool, otherwise they rot or sprout. Humidity of less than 60 percent, and temperatures between 32°F and 41°F are ideal. Add a packet of desiccant powder (such as silica gel) or powdered milk, to combat high humidity. The gel absorbs best. Under good conditions, many types of seed will remain viable for years. The longer you store seeds, the less viable and vigorous they will be. The following table lists some common seeds and their storage life expectancies. Commercially packed seed may store longer than home-grown.

HOW TO COLLECT VEGETABLE SEEDS

Asparagus. Only female plants produce the berries which contain seeds. Harvest when berries turn red.

Beans & Peas. Leave the pods on the plant until dry.

Broccoli. Let buds flower and develop until pods form. Collect after the pods have dried on the plant.

Cabbage. This biennial sends up seed stalk which develops pods. Pick after pods have turned yellow.

Carrot. Seeds on this biennial ripen about 60 days after flowering. Carrots cross with the weed Queen Anne's Lace, so don't allow it nearby.
Cauliflower. Pick after pods turn brown.

Corn. Different varieties cross-pollinate. Keep them separated by at least 100 feet or cover ears with a paper bag before the silks emerge. Hand-pollinate by covering tassels with a paper bag to collect pollen, and then by sprinkling pollen over silks. Allow the ears to ripen on the plant. Husk corn, and hang it until kernels are dry.

Cucumbers. Different cultivars cross-pollinate, so isolate them. Pick after cucumbers turn yellow. Scrape out seed pulp and wash seeds.

Dill. Let seeds dry on plant.

Eggplant. Pick when fruit turns dull and wrinkly. Separate seeds from flesh.

Lettuce. Wait for the last plants to bolt, then let flower. Harvest when fluffy, white seeds form.

Melons. Harvest fruit when ripe, scrape out seeds, rinse, and dry.

Okra. Allow pods to ripen on plant.

Onion. Harvest flowering tops as soon as black seeds are visible. Dry for a few weeks, then gently rub off the seeds.

Peppers. Wait until the fruit has reached the appropriate color for its variety; most turn red. Cut off the top of the pepper and shake or scoop out seeds.

Potatoes. Seeds do develop, but planting from seed potatoes is easiest. Dig up future seed potatoes and let dry in the sun to improve storage. Never do this with eating spuds, because they turn green and bitter.

Pumpkins & Squash. Allow fruit to ripen fully and scrape out seeds.

Radishes. Let flower and harvest when seed pods are dry.

Spinach. Let seeds ripen on plants.

Sunflowers. Allow them to dry on the stalk. You may need to cover sunflowers to protect from birds.

Tomatoes. Pick overripe fruit; squeeze pulp and seeds into a jar. Allow to ferment at room temperature for three or four days. Stir daily and pour off any liquid and floating seeds. Keep only the seeds that sink; rinse and dry them.

Turnips. Dig up this biennial, and overwinter 1-year-old plants in a root cellar. Replant in spring for seed production. Harvest seed pods when dry.

Collecting Seeds

Once you have seeds, the next step is to gather and prepare them for storage. For most plants, it is critical to wait until the seeds are ripe before you harvest them. Failure to do so results in seeds with a low germination rate and poor vigor. Some exceptions are snap beans, lettuce, radishes, spinach, and tomatoes, which germinate fairly well when a little underripe. Although the seeds must be ripe, it also is important to make sure they are not yet rotten or expelled by the plant when harvesting. A dry, sunny day is perfect for gathering seeds or seed fruit.

The method of harvest depends on the type of plant. Many annual flowers, lettuce, and onions release their seeds as soon as they mature. Tie a small paper bag over the developing seed head to catch them as they fall. Wait until fleshy fruits, such as melons, tomatoes, rose hips, shrub berries, or tree fruit, are a little overripe to pick. Scrape the seeds from the flesh of the fruit, soak to remove any residue, and allow to dry completely. Some plants produce capsules or seed pods; snap them off, break open, and shake the seeds out over white paper.

The moisture content of stored seeds is critical to their viability. (Viability determines whether or not it will sprout.) Seeds must be kept as dry as possible. Spread clean seeds out on newspapers in a dry place for at least one week. Hang an incandescent lightbulb overhead to raise the temperature slightly and dry the surrounding air. Temperatures much over 100°F as well as any other factors causing the seeds to dry too quickly will damage them. Some seeds will dry just fine on the plant; poppy seeds and peas are good examples. An alternate method is to wrap the seeds in paper, and place in a jar with an equal weight of silica gel. Small seeds will dry in about ten days, while larger ones can take up to sixteen days. Test for dryness by bending the seeds. Those that snap back are not ready for storage, but those that break are ready.