To prune or not to prune – that is the crape myrtle question
By Ralph E. Mitchell
Crape myrtles are perhaps one of the most popular small flowering trees in our area. The flowers of this tree are summer favorites with colors ranging from white to lavender, and from pink to red. Crape myrtles are low-maintenance plants that often require little pruning. Let’s look at the art and science of properly pruning these well-loved trees.
As a general statement, crape myrtles need next to no pruning and can be left alone. As a matter of fact, if a crape myrtle is planted in a full sun area with room to grow, it will develop a nice rounded canopy with no pruning needed. It is also true that crape myrtles can become so large that pruning is no longer practical. But, sometimes planting locations are not perfect and keeping out-of-bounds plant growth from intruding onto sidewalks or the edges of roads may need attention. It should also be noted that some types of crape myrtles, if left unpruned, can be expected to produce the most flowers. As the degree of pruning increases, the number of flowers tends to decrease. However, the flower clusters in pruned crape myrtles tend to be larger than those from unpruned plants.
The objective of pruning any plant usually involves improving the structure, changing the size of the plant, or removing dead branches. If a crape myrtle does need to be pruned for safety reasons for instance, this can be done at any time of year. Pruning for safety may include removing storm-damaged limbs or limbs that block visibility on a road or walkway. If you need to prune your crape myrtle to improve the structure of the tree, do this during the dormant season. Now while you can actually do light pruning work at any time of year, you are better able to see the structure of the tree in order to remove crossing branches, dead branches, or overly vigorous shoots, when the leaves are off. If you intend to conduct more severe pruning, schedule it late in the dormant period so as not to force new growth that may be damaged by cold temperatures. Tip pruning throughout the growing season can be completed to clean up old flowers and seed capsules. In older types of crape myrtles, this tip pruning can actually stimulate new flowers. This is unnecessary in newer cultivars that bloom repeatedly without any pruning. In general, tip pruning will not interfere with when – and for how long – the crape myrtle flowers.
Pruning crape myrtles often involves a technique called tipping. Tipping is not to be confused with “topping”. Topping, an antiquated drastic method that takes much of the top of the tree off leaving only greatly reduced stubs, is not a recommended technique. Tipping crape myrtles involves pruning just the tips of the one-year old branches which are about the width of a pencil. This gives the tree a nice, neat rounded-over appearance. Tipping takes a good deal of time and can eventually become impractical.
Another unique type of pruning worth mentioning is called pollarding. Pollarding involves the development of swollen knob-like heads at the end of each branch. This pruning technique has a very different look, but allows you to keep the crape myrtle at a given height for the rest of its life. Practiced mostly in Europe, pollarding does require annual maintenance and its appearance may be an acquired taste.
As noted, crape myrtles need little pruning, so think before you cut. For more information on all types of pruning information, please call our Master Gardener volunteers on the Plant Lifeline on Mondays, Wednesdays and Fridays from 1 to 4 pm at 764-4340 for gardening help and insight into their role as an Extension volunteer. Don’t forget to visit our other County Plant Clinics in the area. Please check this link for a complete list of site locations, dates and times – http://blogs.ifas.ufl.edu/charlotteco/files/2018/03/Plant-Clinics-Schedule.pdf. Ralph E. Mitchell is the Director/Horticulture Agent for the Charlotte County Extension Service. He can be reached at 941-764-4344 or firstname.lastname@example.org.
Knox, G. W. & Gilman, E. F. (2015) Crape Myrtle Pruning. The University of Florida Extension Service, IFAS.
Knox, G. W. (2016) Crape Myrtle in Florida. The University of Florida Extension Service, IFAS.