Mine here in Florida grow fine in full sun as long as they have something to climb. I have noticed that young tender vines get burnt if they are laying on the ground. Once they are up on the pole they seem to be fine with full sun. In the wild (both where they are native and here in Florida) they grow in forested environments. So, when the vines are yoing they are in the shade. As they get older they make it to the tops of the trees and get full sun.