Seed saving is a practice as old as humankind. George Washington supposedly thought it was “disreputable” for farmers to buy seeds every year. If you want to save seeds from one year to the next, you need to grow open-pollinated varieties (not hybrids) and know if a plant is self-pollinating or if wind or insects pollinate it. If it is self-pollinating, seeds are usually easy to save, and the plants the next year will look just like the parent plant. If plants are pollinated by wind or insects, they can be cross-pollinated, which means next year’s plant will be a surprise as it will be a cross between the two parent plants. This is not necessarily a bad thing. We’ve eaten volunteer squash that grew out of our kitchen compost pile (a cold pile), and they have been incredibly tasty and beautiful.
Beans are one of the easiest plants from which to save seeds because they are self-pollinating. A bonus of saving bean seeds is that you can eat the ones you don’t plan to plant next year. For years a successful bean crop eluded me. Because I was worried about picking them too soon, I invariably picked them too late, and they were always tough and stringy. I finally came to the conclusion that I was incapable of growing green beans. Then, one day when I was reading through a seed catalog, I realized that I couldn’t go wrong with beans because when they are too mature to be used as green beans, they have another purpose. Although dry beans, such as pintos and black beans, are inexpensive to buy in the store, they are a nice bonus when growing green beans. You can save seeds from any variety and cook them as dry beans. But not every variety makes a good green bean. Some are tougher and stringier than others. Choose varieties that are supposed to be good for green beans and pick them when they are small and tender.
When to pick?
You really can’t pick a green bean too early, but you can definitely pick them too late. Once you see the seeds bulging through the skin of the pod, they will probably be stringy and tough if eaten as green beans, so leave them on the plant to continue maturing and then harvest them in the fall after they have dried and turned brown. After shelling the beans, decide how many to save for planting the following year, and cook the rest.
You can save the dried beans in canning jars with lids. To be certain the beans are completely dry, spread them out on a cookie sheet in a single layer and leave them in an out-of-the-way spot for a couple of weeks. If you notice mold starting to grow on seeds in a jar, you might be able to save them if you take them out of the jar immediately and put them in a single layer to dry more. Lettuce, peas, peppers, tomatoes, and eggplant are also self-pollinated, so saving seeds is easy with them. Although cross-pollination is not impossible, it can still happen, so if you are planning to save seeds, plant the different varieties in different sections of your garden rather than side by side.
For more information
Beans: the perfect intro to seed saving
Planning the Sustainable Garden: What Will You Grow?
Planning the Sustainable Garden: How Much Will You Grow?