As the gardening season winds down and you pick the season’s last vegetables, let some plants go to seed and harvest them for planting next year.
“Saving seeds can be really fun and is a great way to learn about plants,” says Weston Miller, a horticulturist with Oregon State University Extension Service. “If you choose the right types of vegetables, you can keep them going year after year without buying them again.”
The key to seed saving is selecting open-pollinated or heirloom plants, which produce offspring with the same traits.
Hybrids are bred from two different varieties for characteristics, such as disease resistance or higher yield, and won’t come “true to type” in the next generation. Check seed packets or catalog information so you know which type you are buying.
The easiest crops for seed saving are annual plants that self-pollinate, including lettuce, beans, peas, peppers, eggplants and tomatoes.
Collect seeds from the healthiest plants and allow them to dry. Harvest lettuce seed when the seed coat turns hard and dark. Peas and beans are ready for harvest when the pods dry on the plants. Pepper seeds are ready when the fruit is fully mature and starts to wrinkle.
Seeds from annual herbs such as cilantro (coriander), arugula and calendula are easy to save. In fact, these annual plants often self-seed. If you let the seeds mature on the plants and fall to the ground, new plants will start next year.
Tomatoes are a smidgen more complicated. Allow the fruit to fully ripen. Scoop the seeds, along with the gel that surrounds them, and place in a jar of water. Allow this mixture to ferment for up to five days until the seeds sink to the bottom. Then dry the seeds on a paper towel.
Many broccoli family crops—broccoli, Brussels sprouts, cauliflower, cabbage, collards, kale and mustard greens—are part of the same species and are pollinated by insects. Though it is relatively easy to save seeds from these biennial crops, they tend to cross-pollinate easily and you might end up with new—and sometimes tasty—traits.
It is more difficult to save seed from other crops, particularly in a garden setting. For example, beets and Swiss chard are wind-pollinated and cross with each other. These plants require at least 3,200 feet of isolation to prevent cross-pollination. Similarly, corn is pollinated by wind, making it difficult to isolate without special screening.
Carrots are insect-pollinated and cross with Queen Anne’s lace, a common weed. Summer and winter squash flowers are also insect-pollinated and require isolation to maintain true varieties. The fruit grown from cross-pollinated squash seeds often tastes bitter, according to Weston.
Store seeds in tightly sealed glass containers in a cool and dark location. Make sure you label seeds with the seed type and date. A small packet of silica desiccant or powdered milk in the jar can help remove moisture and keep the seeds dry. The refrigerator or freezer is also a good place for storing seeds you collect and seeds you buy. Put small seeds in envelopes and label them. Place the envelopes in sealable freezer bags.