Why?
Saving seed year after year creates a population adapted to local growing and climate conditions, which means it probably yields better results for gardeners in the same locality. To help preserve genetic diversity of seed, people can cultivate seed for rare and endangered varieties. Saving seed is a way to take interest in food sources, food variety, local and global connectedness, sustainability, and self-sufficiency. It can be an educational and deeply satisfying process. Joining seed saving networks provides access to seeds that are not commercially available. The Seed Ambassadors Project produced a zine-style guide to seed saving and stewardship that addresses many commonly asked questions.
Which?
Seed from “open pollinated” or “heirloom” varieties can be saved. These plants produce offspring like the parents, as long as they have not crossed with plants of a different variety. Seed from hybrid varieties is not worth saving, since the offspring will differ noticeably from the parents. Hybrid seed packets are usually labeled “hybrid” or “F1.” Some species (such as cucurbits) require isolation and/or hand pollination to prevent crossing with another variety.
How?
Some basic botanical knowledge is helpful to ensure that saved seed will grow to produce true-to-type fruits/vegetables. This includes knowing the species of your garden plants so you can anticipate what might cross-pollinate, understanding how flowers are pollinated for different species (insects, wind, self-fertilization, or a combination), consideration of isolation distance, and growing a population size required for genetic diversity of the variety. This reference chart from Seed Savers Exchange will answer questions about saving seed from commonly grown garden plants. Since some isolation distances and population sizes are not possible for one home gardener to accommodate by themselves, coordinated growing efforts in a collective (like Oshkosh Seed Savers!) has many benefits. Most seeds remain viable for 2-3 years if kept dry and at cool room temperatures. Some, like legumes and tomatoes keep for many years in the freezer.
If you are new to seed saving, start with some easy ones. Some seed is so easy to save that it self-seeds, producing reliably true-to-type seed because it is not known to cross with other garden plants. You may have witnessed annuals reseeding in your garden, which means you could also collect mature and dry seeds to replant in a more controlled way and/or share with others. Examples in our garden include annual flowers such as calendula, cosmos, larkspur, forget-me-not, sunflower, and bachelor button; native prairie perennials such as penstemon, echinacea, rudbeckia, and meadow garlic; annual herbs, such as dill, borage, and shiso; salad greens such as lettuces, mache (corn salad) and arugula.
Saving seed from cold-hardy biennials works well here.
We’d also recommend trying to save seed from beans or peas. Legumes are very easy to save if you only grow one of each species.
Saving from squashes/zucchini requires some specialized skills which we can teach you.