Nutty Groundnut — Apios americana 'Nutty' Largest Tuber Variety-Massive Potato Sized Originally bred in Louisiana this selection is tops in tuber size. Nuts average 3 to 5 inches in diameter and have a very smooth light skin. Vines can grow up to 50 ft. or more in a single season so trellising would be of benefit. Completely hardy and productive in southern Michigan. Excellent potato flavor. Great fried in ghee.