Is Pruning Necessary?

• Crape myrtles that are never pruned at all still develop a pleasing shape and produce lots and lots of flowers. According to the Virginia Cooperative Extension, a crape myrtle that is never pruned will produce more flowers -- though smaller -- than one that is regularly pruned and will have a longer bloom season. Prune minimally for overall health and shape.
  
  

Start Young

• Start pruning crape myrtles when they are very young so they develop an open center that allows air and light penetration to the middle of the tree. A tree that is pruned to the right shape early in its life will require far less pruning later on.
  
  

What to Prune

• Prune out dead branches and branches that are diseased. Any branches that are growing towards the center of the tree should be removed, as should any branches that cross or rub against other branches. Crape myrtles put out suckers along the base of the plant and those can be removed anytime -- either when they're very young and can be pulled off or when they're woodier and need to be cut.
  
  

How to Prune and Tools to Use

• Every pruning cut should be made as close to the main branch as possible without cutting into the branch collar -- don't leave stubs. Stubs serve as an entry point for pests and disease. Use clean, sharp tools. Dull tools will leave ragged edges that may become diseased later on and dirty tools can transmit disease when they cut through the bark. If you are removing diseased branches, dip the tools in a 70 percent alcohol solution between each cut. For basic pruning, you'll need hand pruners, loppers and a pole pruner.
  
  

Crape Murder

• "Crape murder" is a phrase that refers to the all-too-common practice of lopping off the top of crape myrtles under the assumption that it is necessary to promote flowering. This practice leaves several stumps in the place of branches. When new growth appears, it resembles spines protruding from the stumps. The flower clusters, when they appear, usually cause the too-thin growth to topple under their weight. This practice also weakens the tree, leading to disease problems.