The late growing season is a good time to collect seeds from vegetables and flowers. Seed saving allows gardeners to preserve heirloom varieties or their favorite plants from year to year. Below are the basics of harvesting, preparing, and storing seeds from your garden.
Best Plants to Save Seed From | When & How to Harvest Seed | Cleaning & Preparation | Storage | More Information
Easy Plants to Save Seed From
Look for Open-Pollinated Types
The easiest seeds to save are from open-pollinated plants, as their seedlings usually resemble the parent plants, provided they don't cross-pollinate with other varieties. In contrast, F1 hybrids are produced by crossing two specific varieties. Seeds saved and planted from the fruit of these hybrids won't produce progeny that resemble the parent plant and often yield inferior fruit or flowers.
Look for Self-Pollinated Types
Self-pollinated plants are easier to save seeds from since they don't need external vectors like wind or insects and are more likely to produce seeds resembling the parent. For open-pollinated plants requiring cross-pollination, you can get true-to-type seeds by growing only one variety per season, isolating them by distance, using containment tents made of netting, or growing them at different times of the year.
Easy Plants To Start With
The easiest plants to save seed from are annuals that are open-pollinated and self-pollinated. Beans, lettuce, peas, tomatoes, and peppers are great vegetables for beginning seed savers. Flowers great for seed saving include marigold, zinnia, morning glory, cleome, nasturtium, poppy, snapdragon, and sunflower.
When and How to Harvest Seeds
The timing of seed harvest varies by species. Collect seeds after full maturity; they mature at different rates, just like they flower and fruit at different times. Throughout the growing season, collect individual pods or fruit as they mature. For seeds in dry husks or pods, leave them on the plant to dry. If conditions get too wet or cold, harvest entire plants and hang them to mature.
Harvest seeds from the best-performing plants, focusing on color, taste, form, growth habit, and disease resistance to ensure future generations perform well and produce desirable plants, flowers, and fruits.
Cleaning & Preparing Seeds After Harvest
Cleaning methods for seeds will vary from species to species depending on whether the seeds are in dry or fleshy fruit.
Dry Fruit
Dry fruit seeds, like those in lettuce, radish, grains, beans, peas, and cole crops, are usually dry-processed. Mature seeds can be separated from chaff by threshing, smashing, shelling, or screening to physically separate the seed from the flower head, husk, or pod. Screening with colanders or sieves by passing the smaller seeds through a mesh will separate the seeds from the chaff. Winnowing separates heavier seeds from lightweight chaff by using a fan to blow away the chaff. Seeds are often screened or winnowed multiple times to remove as much chaff as possible.
Fleshy Fruit
Seeds in fleshy fruits, like tomatoes, peppers, squash, and melons, are typically wet-processed. Cut open the fruit, remove the seeds, place them in a bowl with water, and agitate to separate the pulp. Floating debris, pulp, and nonviable seeds can be decanted from the top. Repeat until the water is relatively clear. Soak some species, like squash, to loosen the pulp or ferment others, like tomatoes, to break down the gelatinous covering. Rinse seeds using running water and a colander or screen, then dry quickly with good airflow. Spread seeds over screens, coffee filters, sheet pans, or plywood to dry, but avoid using paper or cardboard. Avoid drying in high temperatures (over 95°F) and direct sunlight. Once fully clean and dry, store the seeds.
Storing Seeds
To ensure seeds remain viable and germinate well, keep them dry and cool. Store seeds in sealed glass jars to keep out moisture and pests (like mice or insects), and place the jars in a cool, dry location like a closet, root cellar, or refrigerator. Test germination rates one month before planting.
After cleaning and processing, dry seeds thoroughly. This is the most important step to successfully storing seeds. Place seeds in labeled envelopes, add an equal amount of silica gel in a separate envelope, and seal both in a glass jar. After one to two weeks, remove the silica gel. Some seeds may dry sufficiently using a fan in a seed drying cabinet. Avoid using a food dehydrator, which usually gets too warm and damages the seeds.