Today I checked the garden and saw that I had four spent beds of bean plants. All the beans had been picked, the variety (Maxibel) is not a rebloomer, so bean production is pau. Time to remove the plants and re-sow.
Most gardeners I know do one of three things with old bean plants.....1) throw them into the compost bin, 2) stuff them into a trash bag, 3) throw them into the woods out of sight. #1 I might do, but 2 & 3-- never. Actually I opt for #4.....feed them to the livestock. In this case, it's the rabbits. My rabbits will eat the entire plant that is cut off at ground level.
Ground level, did I say? Yup. I leave the root system of beans and peas in the ground. These plants form nitrogen fixing nodules on their roots. While the science behind nitrogen fixation is incomplete, the general option is that once the plant and roots die, the root nodules decompose thus making that nitrogen available for the next crop.