I pick mine until they stop blooming which usually allows for at least 3-4 weeks of a good harvest. My garden is arranged so that I can pull out the bush beans to allow my melon vines to expand into their vacated area.

Plant new seeds nearby the original plants. When the older plants start to wear out cut them off at soil level so the younger plants can take over. Cutting rather than pulling also keeps their nitrogen rich roots in the soil.

Rodney

Let them keep growing until they stop producing. If you see blossoms, you'll get more beans.

I will usually get an initial small harvest at about 6-7 weeks from seeding followed by 2 large harvests over the next 10 or 12 days. After that the plants start to decline, blooming slows down, and the quality and quantity goes down but I'll still get a few more pounds a week for a couple more weeks. I try to time my pole beans so they start producing about the time my spring bush beans are done. Then in late July I'll plant more bush beans for a late September harvest.

This is exactly what I needed to know, thank you so much everyone!