Have you pruned your crepemyrtles yet? No, I didn’t ask: have you cut them into broomsticks or hat racks? Have you pruned them? Did you maintain a vase-shaped form with arching, outward-growing branches? If you cut the trunks back to an arbitrary height, then you committed “crepemurder.” The large open-faced wounds that result from this mutilation do not “heal” or callus over rapidly. They provide entry points for fungal organisms that can infect and kill limbs and trunks. The butchered crepemyrtle doesn’t die immediately; a few parts die over a period of time–a limb here and a trunk there. Eventually, the hatracked crepemyrtle looks so miserable that it begs to be pruned at soil level.
If you perpetrated crepemurder in the past, atone for your actions now. The first step to properly pruning a crepemyrtle involves removing any broken, dead, and diseased limbs.
The next step is to stop, step back, and look. Imagine a vase-shaped tree with arching branches that flow outwards. Visualize those long, sun-drenched limbs bearing 6- to 12-inch long clusters of flowers in the summer.
Now begin pruning. With a sharp pair of loppers or pruning shears, start at the bottom and work up. Remove any suckers sprouting from the base of your crepemyrtle. Also, thin out any side branches from the lower third of the trunk to expose the attractive bark. Thinning refers to the removal of entire shoots or limbs back to their branch points–the point of attachment of a branch to the trunk or limb.
Now work your way to the top. Thin-out any inward-growing branches. With the center of your crepemyrtle opened up to sunlight, focus your attention on rebuilding the structural framework of your tree. If you headed-back or topped your crepemyrtle last spring, you destroyed its structure. Bunches of spindly shoots emerged from nooks and crannies around and below the cuts. Keep a few of the thick, well-attached outward-growing shoots and remove the rest. As you selectively thin-out the top, visualize the space occupied by the remaining structural limbs. Imagine a fountain-like canopy with limbs that rise upwards and arch outwards. Finally, head-back or tip-prune any wayward or unbranched limbs to make them fuller-looking.
Now your pruned crepemyrtle should appear treelike instead of like a collection of sawed-off broom handles. But wait–you’re not done yet. When it starts leafing out, come back a few times in the spring and early summer to fine-tune its framework. Pinch out any green shoots growing in the wrong direction and thin out any shoots you had missed earlier. By midsummer your crepemyrtle should come close to looking like the image you had in mind in midwinter.
Pruning crapemyrtles the right way this winter takes a little bit of skill and a whole lot of patience. But the rewards this summer will be priceless.