Sweet potatoes are grown in every state and well-prepared soil of every type produces the best results. Lots of loose soil in a well-prepared ridge gives the potatoes a place to grow. Rows should be about 36 inches apart and fertilizer can be added as the rows are made. A suggested fertilizer is 8-20-30 ( where 8 is the nitrogen). Gardens in the North can warm up the soil with black plastic prior to receiving plants, as sweet potatoes like soil temperatures of 70 degrees and higher. Remember that sweet potato plants are not frost hardy and a cold wind with temperatures even in the high 30’s or low 40’s can harm them. They will need to be protected if your weather turns cold.