For example, every winter, potentially beautiful crapemyrtle trees are pruned wrongly, and reduced to nothing but ugly stubs.
Whacking back crapemyrtles to 4 feet high each year is not only an ugly practice, it is also not sensible horticulture. I don’t like it, see no reason for it and would never recommend it.
Crapemyrtles do tend to grow numerous suckers from their bases and, therefore, do require some pruning every year. But only minimal pruning.
Early training will help eliminate any extensive pruning later on.
Extensively pruning or cutting back crapemyrtles each year only causes them to vigorously grow back what was removed.
The only pruning that should be done each year is to remove suckers and to maintain the tree’s attractive shape by removing deadwood and seed pods.
Heavy pruning in the winter will not force crapemyrtles to bloom more. The only way to stimulate more summer flowering and promote a smaller second flush of blooms is to tip-prune — called deadheading— the old blossoms at the ends of the branches as they fade in late summer.
A crapemyrtle that is not blooming well may be getting too much shade and should be moved to another area to get more direct sunlight. Moving it into more sunlight will also help control powdery mildew.
The right way to prune
1. If you think a crapemyrtle needs to be pruned, do it only during the middle to late winter once the leaves have fallen and the tree is completely dormant. A rule of thumb for pruning crapemyrtles: Don’t cut to see over it; cut to see through it. Remember that crapemyrtles are small trees and are supposed to get 15-30 feet tall. You can give your crapemyrtle a more attractive and formal appearance by shaping the tree over time, removing the lower limbs and having only three to five main trunks.
2. Before beginning pruning, imagine the final size and form you would like your crapemyrtle to have. Begin pruning by starting at the base of the plant and cutting away all suckers that may have developed. Then move up the tree, removing all small spindly twigs from the main trunks. Removing these small twigs will allow the smooth showy bark to be seen and encourage air circulation among the trunks, which helps prevent diseases.
3. If the tree is young and hasn’t been pruned before, select no more than three to five of the straighter, thicker stems to become the tree’s main trunks. The selected trunks need to be evenly spaced, not touching or rubbing each other, and should fan outward in a vase shape. If some limbs are too large for loppers or pruning shears, a pruning saw will be required.
4. Next, move on up the trunk and remove any large branches below 3 feet high. The general idea is to cut limbs back to the crotch or lateral branch at the branch collar (the raised or swollen area at the base of the branch where it joins the trunk). It forms a protective barrier against disease and insects and promotes healing of the wound that results from pruning.
5. There are really no rules for pruning the branches of crapemyrtles above 3 feet. At this point, only take out branches that are necessary. The crapemyrtle may not need any limbs removed or any additional pruning. It’s a matter of personal opinion. Less is better, but any branches closer than 6 to 8 inches or numerous small twigs might need to be pruned.
6. Lastly, prune out the brown seed heads on the tips of the branches that formed after the crapemyrtle flowered. This helps give the crapemyrtle a cleaner, formal look.
Sometimes it’s good to prune
Renewal pruning or cutting a plant back to the ground is sometimes a good idea. If a crapemyrtle is unhealthy, or has been severely damaged or pruned badly, renewal pruning will allow the plant to start all over.
A crapemyrtle that has been renewal pruned will grow back rapidly in about two to three years.
Once the crapemyrtle has grown back, the plant can then be trained and properly pruned to look even better.
Do all renewal pruning in March.
Crapemyrtle varieties come in all shapes, colors and sizes. Pruning large ones into small ones should not be done. If you want a small, manageable crapemyrtle that looks like a shrub, buy a smaller variety.
Whacking off and scarring up large crapemyrtles each year serves no purpose. It’s “crape murder.”
Shane Harris is an extension agent for the Alabama Cooperative Extension System.