Around here, crepe myrtles will bloom from June until it's not hot. There will be a constant flow of confetti-like petals littering our driveway. Some people don't like that and consider it a mess. Not me. Boo Hoo. I have pretty pink petals blowing around my yard. Seed pod will form and can be snipped or left for the birds. The leaves will turn orange-red between Thanksgiving and Christmas.
Crepe myrtles like full sun and well drained soil. Done. If fact, once they are established irrigation should be done only when needed. I've never had problems with mildew; but honeydew is an issue. Aphids or other pests enjoy munching on the vegetation then process the plant material and produce honeydew. That fine mist you experience while strolling beneath crepe myrtles is not a refreshing shower. Nope. It's insect pee/poop. I don't worry about it and alternate my route. Some apply systemic pesticides to resolve the problem. I think I would rather have the honeydew than the poison.
Dallas Arboretum Crepe Myrtles (These are my favorites!)
Pruning crepe myrtles is supposed to be done sparingly. Whoops. Farmer MacGregor didn't read that part and has really giving this multi trunk tree and severe clipping in the past few years. We are now in the process of trying to remedy the damage. If the tree ever gets unhealthy, we'll just remove and replace. But I'm hoping for the best. Perhaps I can contemplate a front yard design incorporating a tunnel of lavender crepe myrtles, but I can't see Farmer MacGregor going for it.