French Filets should be harvest when they are very slender 1/8 to 1/4 inch in diameter. Do not allow them to get much bigger or they can be tough or stringy.
Snap Beans are ready when they are firm, smooth and crisp while the seeds are still small. If you bend a bean in half it will break with a "snap" sound. If you harvest too late the pods can be tough and stringy.
Shelling Beans Harvest green shelling beans (such as lima beans) when the pods are big and large. The pods will be still green. Dry shelling beans can stay on the plant until the pods are very dry, the beans should rattle around in the pod.