Unripe muscadines: 
Muscadines in a bowl (the greenish ones are the scuppernong variety of muscadine) 
Concord grapes (these often do better in northern climes and might work out great for your area): 
Concords are the type of grapes used in making grape jelly and grape candies and etc. The "grape" flavor comes from concord grapes. They are so yummy.