Do you cut off the flower cluster (dead flowers) after they flowers bloom or leave them on the tree?
Prune Off Dead Cluster of Crepe Myrtle Flowers
Certified GKH Gardening Expert
You can cut them off, if you like. This practice is called deadheading and can help the tree produce more flowers in the same season. Here is an article on deadheading: https://www.gardeningknowhow.com/flower/deadheading-enjoying-nature%E2%80%99s-second-bloom.htm