The hardest part about saving seed from pea plants is to refrain from eating every last pea. But if you can bring yourself to leave some of those beautiful pods on the vines, you can reap a different kind of harvest: the harvest of next year’s garden.

The start of the seed-saving process happens before planting, when you are ordering seeds and designing your spring garden. You’ll need to start with heirloom pea seeds. These are seeds that will reproduce true to type and are free of any patents or restrictions. You can find heirloom pea seeds from places like Seed Savers Exchange and Baker Creek. If you want to save seeds from a small garden, it’s easiest if you grow only one variety of pea, though it is possible to grow more than one kind with some care.

Peas are self-pollinated and not very eager to cross pollinate with other pea plants, but if you’re growing more than one variety of peas, it’s best to put some distance between each variety to prevent cross pollination. Some sources suggest that as little as ten feet of space between varieties is enough to prevent crossing, while others suggest a minimum of 50 feet or even hundreds of feet. You can use your own judgement based on the size of your garden and how important it is to you to prevent cross pollination. If you’re growing multiple varieties of peas with a smaller isolation distance, you can further reduce the risk of cross pollination by planting lots of other early flowering plants in the garden to keep the bees busy and away from your pea flowers, or by placing screens or covers over your plants to exclude bees and prevent cross-pollination.

Snow peas, garden peas, and sugar snap peas are all the same species (Pisum sativum), and it is possible for them to cross pollinate with each other. If that happens, you might grow a whole new type of pea that’s not really a garden pea, nor really a snow pea, nor really a sugar snap. You might like the result, or you might not. Even if you’re only growing snow peas, if you’re growing three varieties of snow pea, they could cross pollinate with each other to create a new variety that may or may not be a favorite. If you’re a very relaxed and experimental gardener, there’s nothing wrong with saving mystery pea seeds, growing them, and trying the result! But once you find a favorite pea variety that you really want to preserve, you’ll need to separate it from any other Pisum sativum to ensure that the seeds you save will be true to type. Peas will not cross pollinate with beans (Phaseolus vulgaris), limas (Phaseolus lunatus), black eyed peas (Vigna unguiculata), chickpeas (Cicer arietinum), or anything else that isn’t a Pisum sativum.

Once you have your seeds and your garden design, the next step is planting. I like to plant my peas on St. Patrick’s day here in central Indiana. I dress all in green and lure my husband into the garden and we plant them ceremonially as a part of our holiday festivities. I use a no-till gardening method and prepare my soil in the fall, so I don’t have to wait for the ground to dry out enough to support heavy machinery. In my best years, I build trellises for the pea plants out of bamboo stakes and jute twine. This spring I never quite got around to building the trellises. The plants didn’t grow as tall as they might have with good support, but I still got a decent crop. Peas are a wonderful crop for the organic garden, because they build soil fertility and are relatively free of pests and diseases. Since my goal was to expand my pea plot significantly in next year’s garden, I ate only a small percentage of the pods and left most on the vine to ripen into viable seeds. Next year I’ll have many more plants, so I’ll be able to eat more peas while still saving the same number of seeds. It’s best to save a few pods from as many healthy plants as possible to maximize genetic diversity, rather than to save all the pods from a few plants.

The seeds in the pods are fully ripe when the pods are brown, dry, and brittle. In my garden, the whole plant is usually brown and dry by this time. If your pods are almost dry but you’ve got a hail storm or a hurricane on the way, you can probably pull the whole plants up by the roots and hang them upside-down in a protected location to wait for them to finish ripening and dry fully. If you aren’t facing terrible weather, it’s best to leave them in the ground until fully ripe and dry.

When it’s time, shell the peas out of their totally dry pods and leave them in a cool, dry, shady location for another few weeks to make sure they are all the way dry before storing them. Make sure you store them with a good label including all the relevant information about the seeds. After they are totally dry, they will keep longest in a sealed container in the fridge. If you plan to grow them within the next year or two, it’s fine to store them at room temperature in a cool, dark, dry location.

For further reading, check your library for the book “Seed to Seed” by Suzanne Ashworth, and this article by Seed Savers Exchange. You can also read more about my multi-purpose seed-saving garden in my post A Multipurpose Garden.