Sweet potatoes are rather curious veggies - not as cold hardy as Irish potatoes but they can take more cold than tropical yams. Plant them from slips or starts after the last frost and to hold in soil heat and keep down weeds consider using a black plastic mulch on top of the soil. Don't give them too much nitrogen fertilizer or you will get lots of leaves. less roots to harvest. Dig and store in the fall when the vines turn yellow but before a hard frost. They hate wet soil. Growing on a mound is best. I see some great pies in your future. Keep growing, Marianne Binetti