My Red Bud tree is looking ill. The bark has loosen on its trunk. The leaves...
Unfortunately, there is probably nothing you can do.
University of Illinois lists these potential issues:
"Pests and Problems
- Anthracnose [Trees and Shrubs] (Many genus and species involved)
- Botryosphaeria Dieback/Canker (Botryosphaeria dothidea)
- Gray Mold [Trees and Shrubs] (Botrytis cinerea and other species)
- Verticillium Wilt [Shrubs and Trees] (Verticillium albo-atrum and V. dahliae)
- Wood Rots and Decays (Many genus and species involved)
- Leafrollers (Tortricidae)
- Potato Leafhopper [Woody Ornamentals] (Empoasca fabae)
- Twomarked Treehopper (Enchenopa binotata)
Additional pests and problems that may affect this plant:
Stem cankers and Verticillium wilt."