Guide to Saving Seeds: How to Save Seeds in 7 Steps

Seed saving is a simple method of propagation for home gardeners that consists of collecting the seeds that plants produce and saving them to sow the following year. Saving your own seeds is less expensive than purchasing new seed packets or grown transplants from the store, and saving good seeds can help develop plants with optimal traits to thrive in your own garden’s specific climate.

To guarantee that your seeds will produce the same plant variety the following growing season, only save seeds from open-pollinated and heirloom varieties. While all heirloom seeds come from open-pollinated varieties, not all open-pollinated plants are heirloom plants.

• Open-pollinated seeds: Open-pollinated seeds come from plants that are fertilized by natural methods like pollinator insects, birds, rain, and wind. When two plants of the same variety are cross-pollinated by one of these methods, the resultant seed grows into a plant that is similar to the parent plants, with only slight variations. These variations lead to genetic diversity, which allows the seeds to gradually adapt to the local climate.
• Heirloom seeds: Heirloom seed varieties originate from open-pollinated plants and have a history of passing down desired traits from parent plant to child plant. These valuable characteristics are developed through years of cultivation and may include hardiness, flavor, productivity, pest and disease resistance, and climate adaptability. To be considered an heirloom variety, the seeds typically must originate from plant varieties that are at least 50 years old. Heirloom seeds will always produce offspring true to their parent plant so you can save your seeds to grow next year. You can purchase heirloom seeds at your local garden center or nursery, or you can find heirloom seeds that are fit for your specific region through local seed exchange groups.

Hybrid seeds grow plants that are a mix of two different plant varieties. Plant breeders produce hybrid seeds by cross-pollinating two plant varieties in order to create a hybrid with positive traits from each variety—a process known as hybrid vigor. Saving hybrid seeds is not ideal since many offspring of hybrid varieties will not resemble the parent plant.

While first-generation hybrid plant seeds (also known as F1 hybrids) will produce higher yields of plants with the desired mix of traits, it's a different story if you save seeds from that new batch of plants to grow the following season. These second-generation hybrid varieties (known as F2 hybrids) will only produce a small percentage of plants that are identical to the F1 hybrids.

The process for saving seeds varies slightly depending on the plant species, but there are general steps to follow for saving seeds:

1. 1. Determine when your plant will produce seed. Seed savers looking for plants that will set seed quickly should choose annual plants, such as tomatoes, peppers, lettuce, eggplant, beans, and peas. Annual plants have a one-year life cycle and all set seed in a single growing season. Biennial plants, like carrots, kale, beets, and onions won't produce seeds until their second growing season. Most perennial plants won’t produce seeds until their second growing season, but there are some varieties of perennial flowers that bloom during their first year.
2. 2. Isolate plants to prevent accidental cross-pollination. When saving seeds from open-pollinated plants, keep your plants isolated from other varieties of the same type of plant. If cross-pollination occurs between your open-pollinated plant and a different variety within the same species, it will produce seeds with different characteristics and may lose its beneficial traits. For many plants, you can accomplish this by planting different varieties far apart from each other. Bush beans, tomatoes, peppers, lettuce, and peas are all self-pollinating plants that have little chance of cross-pollination.
3. 3. Make sure the seeds are mature before harvesting. It's essential that your seeds are mature before harvesting or they will likely have a very low germination rate. For dry seeds like peas, beans, lettuce, and grains, simply harvest once the seeds are hard and dry. For peas and beans, you'll know when they're ready if they rattle in the seed pod when shaken. For most wet seeds—like seeds in tomatoes, squash, peppers, zucchini, and eggplant—you should wait until the crops are overripe before you save the seeds. With wet seeds, you may want to assign some fruits for eating that you plan to harvest when ripe, and leave others in your garden longer so the seeds can fully mature.
4. 4. Completely dry your seeds. Whether you're collecting dry seeds from pods or wet seeds out of a crop's fruity flesh, you'll need to make sure the seeds are completely dry after harvesting. For beans and peas, open up their pods, spread them out to dry in a single layer on a paper towel, and keep them in a well-ventilated area out of direct sunlight for a few weeks. To test when they're fully dry, hit a seed with a hammer—if it cracks open it's ready; if it smooshes, allow the seeds to dry longer. For many other types of seeds, place the seeds in a paper bag or paper envelope to provide aeration, and wait a few weeks until they are completely dry.
5. 5. Ferment tomato seeds in glass jars. To yield more viable seeds, tomato seeds benefit from fermentation before drying. Fermenting your tomato seeds will break down compounds on the seed that hinder germination when planted. To ferment your tomato seeds, choose fruits from your healthiest plants, cut them in half, and squeeze out the seeds and pulp into a glass jar. Add a couple of inches of water to the mixture of pulp and seeds and cover the jar with cheesecloth or a coffee filter. Place the jar out of the sun for about three to five days until a layer of mold forms on the surface. Remove the mold and rinse the seeds off in a strainer. Let the seeds air-dry for about five days before storing.
6. 6. Store seeds in a dark, cool, dry place. Keep your seeds in an airtight container like a mason jar, film canister, or pill bottle. Storing your containers in a dark, cool, dry place without changes in humidity is key for the seeds lasting. You can even store seeds in a freezer. Some seeds can last years when stored properly, while others may spoil faster, so look up the seed storage recommendations for your specific plant species to ensure they don't expire before you plant them. Label your container with the type of plant, variety, and date that you harvested the seeds.
7. 7. Before planting, bring seeds to room temperature. If you stored your seeds in the freezer or an exceptionally cold place, make sure you allow your seed container to warm to room temperature before you open it. This will stop condensation from forming on your seeds.

Grow your own garden with Ron Finley, the self-described "Gangster Gardener." Get the MasterClass Annual Membership and learn how to cultivate fresh herbs and vegetables, keep your house plants alive, and use compost to make your community—and the world—a better place.