I've only tried sprouting sweet potatoes that I bought at the grocery store -- sometimes it takes a while, but eventually they really take off with the sprouts.
Caroline, I can't wait to hear how your project goes... are you planning to grow them in tubs this year? I tried them inside a hoop house one summer and got a LOT of vines but only very small tubers. Sometimes I think I should just accept the fact that I live in the north
