Harvest snap beans (bush or pole) when the pods are firm and crisp and the seeds inside are small and undeveloped. To avoid pulling branches off the plant, hold the stem with one hand and the pod with the other, and pull the pod. Pick every few days, taking all the pods that are ready even if you can't use them'pods left to mature signal plants to stop producing new beans. To avoid spreading disease, never pick when the plants are wet.
Harvest filet beans, which are slender baby beans, before the pods reach 1/4-inch in diameter; pick at least every other day.
For shell beans, pick when the seeds are full-sized and plump, but the pods are still soft and have not yet started to dry. Shell seeds from the pods by hand.
For dry beans, leave the pods on the plant until they're papery dry and the plant has begun to die; then pull it up and allow pods to finish drying in a sheltered spot'spread out on screens or hang up to dry. If the weather is wet, it's better to pick the pods as they dry to prevent them from getting mouldy. If plants haven't started to die back before frost threatens, pull them up early'most immature pods will mature. Let the pods dry thoroughly before shelling by hand or threshing. To thresh, spread the pods on a tarpaulin or in a large box, and knead or massage them. The beans settle to the bottom and the pods rise to the top.
Spread threshed beans on screens or plates, and leave them until they can't be dented with a fingernail. Store dry beans in large, glass jars placed in a cool, dark place.
Bean weevils are a problem in some parts of the country - this varies from year to year. Larvae feed on developing beans, and adults emerge from dry beans, leaving small holes. If you see small holes in dry beans, put the beans in a glass jar and place it in the freezer for several days to kill the immature (harmless yet unappealing) weevils.
It's easy to save seeds from bean varieties that you enjoy and that do well in your garden. If you grow a number of varieties, you can save money on next year's seed order. Beans are self-pollinating, which means the flowers pollinate themselves. This makes crosses between different varieties less likely—though still possible'so it's best to plant varieties at least six feet (180 centimetres) apart. Leave the pods on the plant until papery dry, and harvest and store as described for dry beans.