You should save only seeds from plants that are open pollinators. Sometimes open pollinators are referred to as Heirloom varieties. Check the catalog or seed package the original seeds came from and it will be marked as “open pollinated”. If you have a hybrid variety, it will not produce seeds that are true to its parent. Many common vegetables are open pollinators and are easy to save. These include beans, peas, tomatoes, lettuce and herbs.
The methods for seed saving are as follows:
Tomato Seeds: Select a ripe fruit and slice the tomato in half horizontally. Squeeze the pulp, seed and membrane over a container. Mix with water and allow to ferment 2-5 days at room temperature. Stir the mixture a few times each day. Mold may start to form on top, but the seeds will settle to the bottom of the container. At the end of the fermentation process, carefully wash the seeds from the pulp and let them dry on a paper plate for several days until entirely dry. Store in a glass jar or envelope in a cool dry place.
Beans and Peas: Do not pick pods, but allow to air dry until pods become dry and brittle brown on the plant. Pick the pods and allow to dry for 2 more weeks. Shell the seeds and store in a paper bag in a cool dry place.
Herb Seeds: There are many kinds of herbs, but generally they are treated the same. Let the plant go to seed. Allow the seeds to almost completely dry on the plant. Some seed heads such as dill will completely fall apart if allow to completely dry on the plant, so watch carefully and harvest as soon as they seem dry enough, but before they fall from the plant. Harvest by snipping off several inches below the seed head. You can encase the seed head in a paper sack before snipping the stem. Hang the herb upside down with the seed head encased in that paper sack. Tie a string or rubber band around the stems and paper bag. Hang the herb upside down and allow to completely dry. This may take a few weeks. Check a couple times a week and when completely dry, remove the seeds from the seed heads if they have not already fallen off. These seeds can be used immediately for seasoning or stored in a cool dry place.
Lettuce seeds: Allow lettuce to go to seed. Cut the seed stalks from the plant when fluffy in appearance. It will be before all the seeds are dried. You will lose all the seed if you allow the seeds to completely dry on the plant. Dry the seed stalk as described for herbs above or dry by placing the stalks on a piece of white paper. When the seed stalk is completely dry, shake the seed stalk over the paper and collect the seeds. Store in a glass jar or envelope in a cool, dry place until ready to plant.
Be sure to mark all your seeds carefully. Mark the variety and the date you harvested the seed. If seeds are stored properly they will remain viable for several years.
If you choose, you can also purchase seeds from a seed company that are packaged and sealed for long term storage. These prepared #10 cans contain open pollinators of peas, radish, onion, spinach, cabbage, swiss chard, beets, carrots, lettuce, beans, corn, cucumber, zucchini, pepper, winter squash, and tomato. Contact Mountain Valley Seed in Salt Lake City for this option.