I had gophers do that to my green beans. They tunnelled underground and tried to pull the plants under. All the plants broke off at soil level and died. That year I only got one mess of beans for dinner. Very disappointing. I think the answer is raised garden beds lined with some type of barrier that will allow for water circulation but keep the critters out. I guess it's trial and error to find out which plants, such as potatoes, zucchini, or beans, the critters like and then plant them in the raised beds.