- Mark your best plants while they are blooming and save those seeds. The best plants produce the best seeds.
- Seeds must ripen fully on the plant before you harvest them. (Bean and pea pods, for example, turn brown and dry.)
- Keep a few seeds back, in the spring-time, so you have a standard against which you can compare your fall seeds. Compare colour, size, and especially plumpness.
- Look for insect damage – sometimes just pinpoint holes in the seed where critters have burrowed in – and discard affected seeds.
- Choose seeds from many plants to maintain the natural diversity of their traits. For example, if your beans have a natural variation in colour, save some seeds of each colour to preserve the assortment.
- If you want to breed a new strain, collect seeds from the plants you like best.