Common Bean, Green Bean

Beans, garden peas, and cowpeas are not only among the easiest plants to grow, saving seed from them is the height of simplicity.
...Read More
In general, legumes should be allowed to dry on the vine. If frost threatens, or if there are other reasons to bring them in before they are dry, the recommended approach is to pull the entire plant, roots and all, and hang it upside down inside. Most of us do not have the room for this, so an alternative method is to just pile the plants in a warm, airy room, right on the floor, until they dry. A dry basement, or even a garage, is ideal for this.

The seeds, themselves, will need additional drying. To do this, remove them from their shells and store in a permeable container open to the air. Woven baskets are good for this. Periodically stir the seeds, to assure they are exposed to the air.

Seeds are fully dry when they shatter, rather than just crush, if you hit one with a hammer.

To thresh, or not to thresh, that is the question. Hybrids and many bush varieties ripen all at once. Because of the sheer volume involved, threshing makes sense for these varieties. Heirlooms, and some bush varieties, tend to come in over a longer period of time. You can thresh these, if you wish. But it's almost as easy to hand open them as they are ready.

Alternatively, you can just save the pods until you have enough to justify threshing. And, by the same token, you can store the pods from bush varieties, and hand-separate them a few at a time.

Vines and pods can be tilled right back into the garden, or added to the compost pile.

Legumes are very susceptible to bean weevils, whose larvae live inside the seeds. Treatment consists of freezing the dried seed for three to five days at zero degrees. Other than this treatment, it is not recommended that legumes be stored in the freezer long term.

Officially, legume seed remains viable for three to five years, depending on species. However, legumes---especially common beans--- can remain viable for incredible lengths of time when stored under cool, dry, dark conditions. Anazasi beans, and New Mexico Cave Beans, are just two instances where seed was stored for centuries, yet still germinated.