When and how to carry out pruning of <em>Lagerstroemia</em> or crepe myrtle?

Why prune crepe myrtle?

Pruning crepe myrtle is not essential, but it offers benefits for appearance, health and maintenance of the bush. It allows giving a particular form, for example by pruning into a standard (to obtain a straight, unramified stem topped by the crown), or by pruning into coppice shoots (to obtain several ramified trunks that arise from the base of the bush). A standard is very elegant, but pruning as coppice shoots has the advantage of offering a more natural, wilder appearance. We recommend the latter, which seems particularly suited to Lagerstroemia, allowing its architecture to be showcased.

If space is limited or if you grow it in a pot, pruning Lagerstroemia will let you retain a slightly more compact habit. Pruning Lagerstroemia also helps to aerate the centre of the bush, letting air and light through. It promotes a beautiful and generous flowering, notably by removing weak and fragile branches that would struggle to carry the flowers. It can also help rejuvenate an ageing bush, renew its branches and restore vigour.

When pruning, we recommend preserving Lagerstroemia’s graceful spreading form (photo Ryan Somma)

When should pruning of lagerstroemia be carried out?

When to prune crape myrtle? Lagerstroemia should be pruned in late winter, between late February and early March, before new leaves appear. Winter is then almost over and temperatures will start to moderate, but the bush has not yet restarted its growth. It can then produce new branches in spring.

Pruning of Lagerstroemia in October or before winter is not recommended, as it would make it more vulnerable to winter cold and could compromise its flowering the following summer.

Crape myrtle (Lagerstroemia) is an outstanding choice for small gardens, offering spectacular autumn foliage in warm hues that extends visual interest long after its summer flowering.

How to prune crepe myrtle correctly?

We recommend pruning crepe myrtle every year. However, most significant prunings occur during first years; they give it its overall shape. These are formative prunings. Later, lighter maintenance prunings can be carried out to keep a balanced habit. In general, lagerstroemia is a vigorous bush that grows quickly; you can prune it quite short. It should have no trouble resuming growth and producing strong new branches.

We recommend making clean cuts with a well-sharpened, disinfected pruning shear to avoid transmitting diseases to the bush and to help wound healing.

How to prune crepe myrtle? Here are the steps:

A Lagerstroemia ready to be pruned

• Start by stepping back and observing general shape of bush. It is important to preserve its natural shape. We recommend pruning from base upwards, working upwards and removing poorly placed branches that spoil a natural, balanced shape. A lagerstroemia cut to coppice shoots should take a nice spreading habit. We recommend keeping between three and five main trunks.

Remove old flower clusters and any dead or damaged branches

• Look at base of bush, and if you see any suckers, remove them by cutting them very short.
• Then work gradually upwards and remove damaged, dead, poorly placed or crossing branches. Eliminate those that seem most fragile and least attractive. Prioritise retaining branches positioned towards outer canopy. However, if branches obstruct passage, take up too much space, or are too close to a building, you may prune them.

With a pruning shear, cut at an angle just above an eye

• Select a few main branches, but remove branching that seems excessive. Do not hesitate to to let light through and give it a lighter, more open silhouette.

Ideally, cut just above a node, if possible angled towards outer canopy. This encourages branch growth outwards rather than towards centre of bush. You can cut branches back by about 10 cm, leaving a few eyes on each.

Same Lagerstroemia before and after pruning

Good to know: although lagerstroemia tolerates severe pruning, this should be done with care in late winter so as not to compromise summer flowering or vigour.

Should you cut off faded flowers of crape myrtle?

It is generally recommended to remove spent flowers from crape myrtle for several benefits to the plant. This practice, called deadheading or removing spent flowers, stimulates production of new flowers by encouraging a second flush of flowering, thereby prolonging the summer display.

By removing spent flowers, you also prevent seed formation, which allows your bush to devote all its energy to growth of branches and development of future flowers rather than to seed production. Moreover, it helps maintain a neater, tidier appearance for your crape myrtle throughout the season. It is therefore a simple action that promotes more abundant flowering and better vigour in the bush.

Did you know?

It is also possible to prune Lagerstroemia to create a bonsai (proof that it can withstand severe pruning)! This produces a beautiful miniature tree with a sinuous trunk.

Warning: pruning that is too severe or carried out too late on Lagerstroemia can lead to unsightly “stubs” and compromise flowering the following year.