I have several crepe myrtles that will bud out but never fully bloom. My soil is pretty much clay and I live 25 miles north of Louisville, KY. They bud in Aug. when I see them, but in Louisville they're in full bloom in late June. What can I do?
How to Get Crepe Myrtles to Bloom
Certified GKH Gardening Expert
How is the drainage around the trees? Are they in standing water quite a bit?
I suspect that the blooms are not opening due to stress on the tree. As you have clay soil, this can make for waterlogged ground, which would stress the trees.
If this is the case, try to improve drainage around the trees and do not provide additional water to the trees.
If this is not the case, try treating the trees with a pesticide and fungicide. The trees may be stressed due to an ongoing pest or fungus infestation and treating them for this will help reduce the stress that is preventing them from blooming.
Another possibility is that you have varieties that are not suited for your area.