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.