Seed Saving Fundamentals

Seed Types and Plant Families

There are a few fundamentals to know when saving seeds. Once you are familiar with these concepts you can easily and successfully save just about any seeds you want.

Types of Seeds

Open-pollinated or heirloom varieties

Seeds that have been grown for so many generations that their physical and genetic qualities are relatively stable. Open-pollinated can refer to self-pollinating plants (tomatoes and beans), or cross-pollinating plants (cabbages and beets). Open-pollinated is usually used to describe plants that are not hybrids. This seed will be "true to type" if saved. In simple terms, you will reap what you sow. Because we want to be sure that people are getting seeds that will produce "true to type," the Seed Library is only sharing and accepting donations of open-pollinated seeds.

Hybrid seeds

If a packet has hybrid, F1, or VF written on it, seeds from those plants will not produce plants like the parent plant. They may produce something somewhat or very different, or they may produce nothing at all. Hybrid (or F1) refers to plant (or animal) varieties that are achieved by the crossing of two distinct inbred lines. Seed saved from hybrids will not grow "true-to-type." Hybrids are used extensively in industrial farming because they are uniform and yield all at the same time, which is often good for commercial needs, but not for the purposes of the Seed Library. We only want seeds properly saved from open-pollinated or heirloom plants.

Plant Families

If you learn the family, genus and species of vegetables, you will also learn their basic seed saving needs and risks.

Families define the basic form of the flower parts of plants. All plants with the same flower (and reproductive) structure are in the same family.

Genera (singular: Genus) define more closely related plants. Crosses between genera are rare but can occur.

Species define specific botanically recognized plants with similar fruit, flowers, and leaves. Plants within one species will readily cross with each other.

Cultivars are cultivated varieties that can cross with each other but will not cross with varieties of other species. When we save seeds we usually want to maintain a cultivar or breed a new one.


Family: Cucurbitaceae Genus: Cucurbita Species: Cucurbita pepo Cultivars: Acorn squash, Warted gourd

How to Save Seeds - Seed Processing

To save seed there are only three simple processes to know. Once you have an understanding of each of the processes, you can save almost any seed.

Dry seed processing

Refers to seed that dries down on the plant and needs to be kept dry until it is sown. The steps involved are harvesting (usually cutting the seed stalk off of the plant), threshing (separating the seed from the stalk and chaff) and winnowing (removing the seed from the chaff using a breeze). Dry seed processing is used for grains, lettuce, brassicas, onions, beets, carrots, celery, cilantro, and chicories, among others.

Wet seed processing

The process by which the seed of many garden fruits are saved. This includes melons, peppers, eggplant, tomatillo, and squash seed. Wet seed processing involves removing the seed from the fruit, rinsing clean of debris, and then drying. A jar of water can be used to separate seed from debris -- seeds sink and debris usually floats. Drying the seed quickly and completely after wet processing is very important.

Fermentation seed processing

Similar to wet seed processing, but the seeds and their juices (as in tomato and sometimes melons and cucumbers) are mixed with a little water and allowed to ferment for a day or few. The fermentation process breaks down germination inhibitors such as the gel-sack that surrounds tomato seeds. When a layer of mold has formed on top of the water and the seeds sink, the fermentation is complete. You simply need to add more water, swish it around, then decant the mold and pulp. You may need to repeat this process several times, as the good seeds sink to the bottom and the scum floats off the top. After all of the pulp, bad seeds, and mold is removed, drain the water from the seeds and set them out on a plate, screen, or paper towel to dry. Once the seeds are thoroughly dry, place them in a moisture-proof container, label and store them for the future.