Pruning to Promote Plant Health

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In urban and suburban settings, pruning is an important part of maintaining tree and shrub health, creating strong tree structures, and promoting an aesthetically pleasing display. Properly pruned trees provide shade and beauty to the buildings they frame and light and sun to companion plants around them.

In large trees, dead branches at the top of the crown provide important nesting sites for bluebirds, shutterstock_273414491.owl in tree owls, and native woodpeckers. So, when pruning large trees, it's important to have an arborist evaluate the branches and only remove the ones that might fall and injure people or damage property. In small trees, removing dead branches and selectively pruning living branches improves a tree's shape, increases the flow of air and light through the crown, and makes it less vulnerable to disease and the impacts of severe weather. This Arbor Day Foundation video further describes the reasons why trees should be pruned.

When to Prune

Pruning Approaches

Crown thinning and crown raising are two pruning approaches that are typically used to grow trees into maturity with natural structure, good health, and an appealing appearance. Employed particularly for hardwoods, crown thinning helps maintain the tree's form by removing branches to allow more light and air to flow through the crown. Crown raising removes branches from the underside of the canopy to help ensure the safety of people, pets, vehicles, buildings, and lines of sight. The Rules of Pruning and the ABCs of Pruning videos describe pruning techniques.

Pruning Practices that Harm Trees

Topping and tipping ("heading") are two pruning practices that are detrimental to tree health, force an unnatural form to the tree, and therefore should be avoided. Topping happens when horizontal cuts are made to upright branches across the tree's crown. Tipping, on the other hand, happens when vertical cuts sever lateral branches, reducing the crown's width. In both cases, the tree is unnaturally cropped, leaving it vulnerable to growing spindly, weakly-attached, and unattractive branches. These practices weaken the tree, and over time, make it more susceptible to disease and the impacts of weather. Note the pruning section in the North Carolina Urban Forest Council's Tree Owner's Manual for additional information.

Stop the Chop and Shape the Crepe

Crepe Myrtles, Lagerstroemia, with flowers in pink, purple, lavender, white or red, frequently grace southern urban landscapes. They were extensively planted due to their vibrantly colored flowers that blossom in the summer, and because they can tolerate both heat and drought.

Well pruned Crepe Myrtles, like the purple one pictured, have robust flower blossoms that last all summer. Unfortunately, Crepe Myrtles are often improperly or severely pruned in the winter under the false assumption that topping helps the tree and encourages it to produce more blooms. Actually, the opposite is true. Topping harms the tree over time, causing fewer flowers that last a shorter duration. The Tree Topping Story in the North Carolina Urban Forest Council's Tree Owner's Manual addresses and debunks these fundamental myths about topping Crepe Myrtles.

Cary's Shape the Crepe campaign draws attention to the widespread, unnecessary, and harmful "topping" practice (pictured below) -- often called "Crepe Murder" or "hat racking"-- and provides guidance on proper pruning to keep them healthy and producing beautiful blooms.

Topping leads to an unnatural and unattractive broomstick form and weak limbs pictured below:

Instead of topping, follow these best practices to help Shape the Crepe and watch it thrive!

Remove:

up to all but five main stems,
branches that are crossed or rubbing another branch,
branches that are growing toward the center,
suckers, and
dead, diseased, or damaged limbs.

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How to Prune a Crepe Myrtle: A Step-by-step Guide

This video from Leaf & Limb shows the proper technique for pruning a crepe myrtle to increase its health and appearance while controlling growth and reducing hazards.