We plant our potatoes around St. Patrick's Day, and are in zone 8b in central Texas. Instead of "hilling" potatoes we dig a trench about 6" deep and plant the cut potatoes. We cover as soon as the greenery appears, and a trench saves a lot of work.
I've always planted on Valentines day with harvest around Memorial day. I had to hold off due to our late winter freeze but, they are all planted now. Just guessing but, I would think in NC you would be on a later schedule.
Dig a 6" deep row. I plant 1" potato cuttings with 1 eye 3 weeks before last frost in bottom the deep row. I cover cuttings with 1" of soil. If plants grow up before last frost and there is a chance of frost it is very easy to cover the 6" deep ditch with a board or cardboard or tarp. Remove cover next morning before sun comes up. Last frost at my house is usually April 20.
If potato plants get frost bite no problem potatoes are 1 of few plants that will grow back. Do not give potatoes nitrogen fertilizer or you get very large plants and tiny potatoes. Feed your plants lots of phosphorus & potassium & water. If plants get taller than 2 feet cut them shorter you will get larger potatoes.