Q.single trunk crepe myrtle tree
2nd year planted. Tree is 12 ft tall, lots of small branches. Something eating leaf tips and no blooms. Fertilized lightly to increase acidity. Can I prune branches so fewer will get bigger for next year? Expensive tree.
Here is information on pruning these trees: https://www.gardeningknowhow.com/ornamental/trees/crepe-myrtle/best-crepe-myrtle-pruning-time-when-to-prune-crepe-myrtle.htm
If you have a blooming issue, then this article should help: https://www.gardeningknowhow.com/ornamental/trees/crepe-myrtle/crepe-myrtle-not-blooming.htm
As for possible pests, it could be scale or aphids. Treat with a pesticide. I like neem oil as it is safe for people and pets and also treats the fungus that commonly accompanies these pests. Here is more info: https://www.gardeningknowhow.com/problems/pests/neem-oil-uses.htm