How and When Should You Prune a Crape Myrtle in Florida?

Crape murder is the habit of cutting every trunk of a crape myrtle back to the same height each winter. It leaves thick stubs, sometimes called knuckles, with a crown of whip-like sprouts growing out of each one the next spring. The crown is the leafy, branching top of the tree.

It is topping, the same practice we avoid on oaks and every other tree. UF/IFAS calls crape myrtle pruning one of the most controversial parts of caring for the tree, and its pruning guide, written by Gary Knox, Ed Gilman and others, lays out what the research found when topped trees were compared to trees that were pruned lightly or not at all.

• Later and fewer flowers. Topping can delay flowering by up to a month, and the number of flowers goes down as pruning gets more severe. The flower clusters can be a little larger.
• Weak new branches. The long sprouts that grow from cut ends are weakly attached and slender. Some break, and many droop after a rain.
• Decay. Large stubs expose a lot of wood to insects and wood-rotting fungi, and topping leaves dead stubs throughout the tree.
• Less stored energy. Cutting off large stems removes the starch the tree stored, and a smaller canopy makes less food.
• More sprouts to remove. Hard pruning triggers sprouts from the roots, the base and the trunk. Unpruned trees produce the fewest.
• It does not keep the tree small. UF/IFAS found pruned trees often grow back to their original size within a couple of years.

The UF/IFAS Gardening Solutions page adds that topping can shorten the life of the tree. Read the UF/IFAS crapemyrtle pruning publication and the Gardening Solutions pruning page.

Many people top a crape myrtle because the neighbors do.

The other reason is size. A large variety planted under an eave or next to a driveway will keep reaching for the space it was bred to fill. UF/IFAS groups crape myrtles into semi-dwarf types at 6 to 12 feet, medium types at 10 to 20 feet, and large types over 20 feet. Choosing one sized for the spot is what keeps pruning light.

If a crape myrtle has to be cut hard every year to fit, the lever you have is to replace it with a smaller variety. In my opinion, that often costs less over the years than topping it every winter.

UF/IFAS puts structural pruning in the dormant season, while the tree is leafless, typically December through February. Severe pruning, if it has to happen, should come late in that window. Pruning too early can push out new growth that a cold snap can damage.

Hard pruning during the growing season is not recommended. Safety pruning is different: a broken limb, a dead branch, or a low limb over a sidewalk can be taken off any time of year.

Seed pods can stay. UF/IFAS says seed capsules left on in winter do not affect flowering the next season, so removing them is a matter of looks. For timing on the rest of your trees, see when to trim trees in Florida.

A well pruned crape myrtle looks like nobody touched it. You should still see the smooth, peeling trunks and a natural, vase-shaped top. Many crape myrtles in a sunny spot with room to grow need little or no pruning. When they do, the work is targeted:

• Dead, damaged or diseased branches, cut back at the branch collar. The collar is the slightly swollen ring where a branch joins a larger one.
• Crossing or rubbing branches. Where two limbs rub, take out the weaker one.
• Branches growing into the center of the crown, which crowd it and hold moisture.
• Sprouts from the base and roots, sometimes called suckers. UF/IFAS suggests removing them at least once during the growing season so they do not become extra trunks.
• Clearance. Lower limbs over a walk, a driveway, or a roof, cut back to a branch union instead of leaving a stub.
• Tip pruning, if you want it. Light cuts through stems about the diameter of a pencil on the outer canopy. It is optional, and UF/IFAS says many newer varieties do not need it to flower.

Our arborists follow the ANSI A300 pruning standard on crape myrtles the same as on oaks. Our tree pruning service page explains how we make reduction cuts and why we do not top.

Pollarding is an old, planned way of pruning that can look like topping from the street. The difference is where and how often the cuts are made. On a pollard, the cuts go through young branches, about three years old or less, and the sprouts are removed every year back to the same point. Over time a knob, called a pollard head, forms there, and UF/IFAS says it should not be cut off because it holds stored energy with little decay.

Because the cuts stay small, UF/IFAS says they are covered by new wood faster, and pollarding leaves fewer dead stubs and less decay than topping. It is a commitment to the same cuts every winter for the life of the tree. In my opinion, most homeowners are happier with a crape myrtle left in its natural form, but a pollard done well is a legitimate choice.

A topped crape myrtle can usually be brought back. UF/IFAS describes two ways:

1. Train the sprouts. On each stub, keep the two or three strongest sprouts and remove the rest. You may need to repeat this for more than one season.
2. Start over from the ground. While the tree is dormant, cut it back to within 1 to 2 inches of the ground. Once the new shoots grow, keep three to five of the strongest per trunk and remove the rest. UF/IFAS says a natural form may take three to five years.

The second option is a big step. UF/IFAS also notes that pruning large, old crape myrtles can cause more stress and decay and can even kill the plant. Which way to go is a decision you and your arborist should make standing under the tree, looking at how big the old cuts are and whether decay has started in the stubs.