I think this practice of crape murder got started because they bloom on new wood. The idea was that the more they are pruned back each winter, the more growth will occur, meaning more blooms. But crape myrtles bloom just fine without doing that. One of the most spectacular blooming crape myrtles every summer is the state champion tree on Telfair Street and it hasn’t probably ever been pruned, except for cutting off lower branches. If someone feels that they have to be pruned to a lower size, they can be cut to give them a more natural appearance.
Why, other than appearance, is crape murder, or topping, such a bad thing? First of all, it results in a “witch’s broom” appearance and a tree that is no longer in proportion. Topping causes profuse growth at the site of the pruning, basal sprouting, and increases susceptibility to disease and insects. It encourages growth that is too dense to allow air movement and light to reach the inner branches. As I mentioned before, it causes large knobs to appear where plants have been trimmed repeatedly and the topped tree has an unsightly appearance until new growth appears.
Although topping may result in larger blooms, those flowers will grow on thinner, weaker branches. Every summer I get phone calls or emails from people asking me why the branches on their crape myrtles are breaking. This happens a lot when we have afternoon showers for several days in a row. These spindly branches just cannot support the weight of all that foliage and blooms.
Unfortunately, topping may also shorten the life of your plants.
About the only pruning you should be doing is removing suckers that may sprout from the base of the plant. The older varieties are worse about doing this than the newer varieties with Indian names. When you plant a small crape myrtle that will grow into a large tree, you can gradually raise the lowest branches each year until they are as high as you want them.
If you need to “rehabilitate” a murdered crape myrtle, this is what you do:
The first method is to decide how many main trunks you want to keep. Most people like multistemed plants, so you might keep anywhere from two to five of the strongest ones. Go ahead and prune them back pretty much like they have always been except this time, cut just below those gnarly knobs. They will basically look like they have in previous winters except the knobs are gone. This spring, you will get a heavy flush of sprouts just below your pruning cut. After you let all of the sprouts grow a few inches, pinch them all off except one. It’s probably better if you keep a sprout that is on the outside of the trunk to help the plant spread out more.
The one sprout you keep will become your new trunk or leader. As the summer goes along, you will continue to get new sprouts below your pruning cut. Just keep them pinched off.
You will be amazed at how well these new leaders blend with the old trunks after one season. You will be on your way to having a natural looking small tree.
One reason I hear as to why they are butchered back each is “They are too close to my house to let them grow.” If this is the case, you can still prune them back to give them a more natural appearance. Cut back the plant to within one to two inches of the ground. After two to three weeks of growth in the spring, select two to five (again, however many trunks you want) of the most vigorous shoots on each trunk and remove all others. Remove any new shoots that emerge later. Assuming they need cutting back every year to keep them in bounds just cut them back to one or two inches from the ground each year. If you can let them grow a little larger, prune the limbs back to where they join another branch and not at the same place each year. This will prevent them from developing those knobs.
If you have a case where the crape myrtles are planted too close to the house and must be pruned back each year, you might consider replacing them. We now have crape myrtles that will get the ultimate size we want, so that drastic pruning is not needed. Crape myrtles vary now from dwarf (3 to 5 feet), to midsize (5 to 10 feet) to small trees (10 to 20 feet). They also will come in any color you would want.
Let’s break the crape murder habit and get our plants to look like what they were meant to be – a beautiful, natural looking plant.
REACH SID MULLIS, THE DIRECTOR OF THE UNIVERSITY OF GEORGIA EXTENSION SERVICE OFFICE FOR RICHMOND COUNTY, AT (706) 821-2349 OR SMULLIS@UGA.EDU.