KEY problem is climate, specifically winter lows. But, with climate change, I’m now routinely fruiting some of the cold-hardiest muscadines in NW Arkansas. I don’t spray a thing. They are very vigorous, so be prepared to prune, as pruning is necessary to keep plants healthy and bearing.
Muscadine pollination is unique: plants are either self-fertile or female. Self-fertile varieties can be planted by themselves and still have fruit. Female varieties must have a self-fertile variety within 50 ft.