We were talking about sunchokes at a seed saving event today at the farm. Apparently they get woody during the summer when they are actively growing, and that is why they are harvested in fall or spring, after the plant has put the sugars into storage in the tubers.
Like Carolyn said, the patches are forever.
There's no way that there won't be a small tuber to escape harvest and grow again. Very easy, so if you like them Mensplace, I think it only takes a year to get something to eat. I'm with the others who concluded that a little goes a long way... not something I would ever eat a lot of. I do have a patch, though.
