I live in Missouri. We have awful summers! Very hot and humid, especially July and August. I just don't want to wait too long or plant too early and end up with nothing (potato wise).It may depend on your area you may be able to plant them after the last frost if your summers are very cool but here we plant them with the peas about 8 weeks before the last frost. You do have to protect potatoes from frost if they’re above ground when a frost comes though.