I planted my blackberries last year and only got a handful of berries. This year they are nearly as tall as I am and loaded with berries. But the strange thing is there are three huge stalks that are very thick that have sprung up from the base of the berry bushes. One on each bush and they have no berries on them just lots of leaves and so much taller perhaps a foot or more than the other vines. What is the deal? Should I cut them off? Do I wind them around my blackberry wires, what to do? Actually, I am realizing I knonw very little about growing these.