· Brent Wilson's Answer
· Hi John, In order to give a more accurate opinion, it would be nice to see a picture. However, basically, there are three ways you can go regarding corrective pruning of a crape myrtle that has been cut back too closely to the knuckles for many years.
The first method involves leaving the knuckles there, allowing the tree to reestablish itself, doing no pruning at all except to remove suckers from the base of the tree or branches that emerge along the trunks beneath the canopy.
The second method involves leaving the knuckles there and cutting back branches that have sprouted from the knuckles to about 12 inches or so above the knuckles. This process can be repeated in late winter or early spring for several years and then the tree can be left alone to grow naturally.
The third method involves removal of the knuckles by cutting the main branches just beneath the knuckles, then following proper pruning practices for several years at which time the tree can be left alone to grow naturally.
Which method you choose might depend on several factors including the age and height of the tree. I might use the one of the first two methods for older, larger trees and the third method for smaller trees.
Here's a link to an article providing proper pruning instructions for crape myrtle. http://www.gardenality.com/Articles/344/How-To-Info/Pruning/How-To-Prune-A-Crape-Myrtle/default.html
Keep in mind that after several years of properly pruning a crape myrtle that further pruning is not necessary. Also, any major pruning should be performed in late winter or very early spring, before new growth has begun to emerge.)