The stiff purple discoloration that hit our courtyard dogwood has now spread to my J. hydrangea and v. creeper. They are very stiff and then fall off. Last year the tree defoliated and then didn't bloom in the spring. Someone suggested heat stress. I'm from the north so I'm unfamiliar with the symptoms. It's no hotter than usual -- 85-95. If it is heat stress, any suggestions other than shading them?
FYI: The underside of the leaf is a lighter green without the purple-brown.
Thanks! http://forums.gardenweb.com/forums/pests/msg0720315222899.jpg