Care & Pruning of

Crape Myrtle

 

Star-Tip 1002

Gardening Tips for successful and beautiful Landscapes and Gardens

 

Remember. When all is said and done; It is up to you as the owner of the crape myrtle, whether you want a shrub or tree, to prune it in the way that you prefer.

 

The 1st thing you should know about Crape Myrtles is that they are different from most other trees and many other shrubs in that they bloom on what's called "New Wood or New Growth"(most tree's flowers come from the growth they made the previous year).

Therefore, anything that you can do to make the crape myrtle  grow once it leafs out in the spring will result in more flowers this coming year. Crape Myrtles thrive on water and fertilizer and  if you fertilize once a week or every 2 weeks you will have more flowers for a longer time than you know what to do with. Low nitrogen and high phosphorous

 

 

One of the most prolific and beautiful bloomers, Crape Myrtle flowers on new growth of the season, so you can prune plants any time during the late winter or early spring before growth begins without loss of flower buds.

 

Avoid pruning in early fall before the first frost, because pruning forces new growth and keeps the plant from going dormant. Severe freezes can kill the plant if it is not fully dormant.

 

Your Crape Myrtle can be a Stand-out in your neighborhood!

 

Pruning results in an abundance of new shoots that form flowers. It also reduces the amount of vegetative growth and funnels the energy of the plant into new growth and flowers. Pruning, however, is not essential for flowering. Some spectacular floral displays can be seen on old, unpruned crape myrtles along roadsides. Flower clusters are usually smaller on unpruned crape myrtles, but the number of flower clusters is often greater.

On cultivars that bloom before mid July, pruning to remove spent flower blossoms after they fade, is useful. It will stimulate new growth, and so produce another blossoming in late summer. A second bloom is sometimes difficult to force on cultivars that bloom after mid-July.

The type and amount of pruning that should be done each year depends entirely on desired shape and size. On large old crape myrtles, heavy pruning may not be advisable, since the tree form is the desirable feature. Crape myrtles in tree form make wonderful accent plants or specimen trees.

 

To develop a multi trunk tree shape:

Select three to five well spaced trunks growing from ground level to become the main trunks. Remove side branches from these shoots about halfway up their height. As the plant continues to grow taller, more of these lower side branches can be removed each year so that the canopy begins 3 to 4 feet above ground level.

Before

After

You should also remove suckers (new spouts that grow from the base) periodically in order to maintain the desired tree shape. Some gardeners apply a synthetic plant growth regulator, called NAA (naphthalene acetic acid), to suckers after pruning to prevent them from resprouting.

 

To develop a bush:

Some gardeners prefer growing crape myrtle as a compact shrub instead of a tree. To get these results, prune the stems back to approximately 12 to 18 inches above ground level each year. Severe pruning will not kill or injure a healthy plant. Prune before growth begins in the spring. The result will be an abundance of new flowering shoots.

 

To develop a shrub:

If an intermediate size of shrub is desired, prune moderately by removing the twiggy growth smaller than pencil size. This annual pruning will stimulate more vigorous growth in the spring.

If you want intermediate size shrubs, cut out only small branches less than pencil size.

Prune back to within 12 to 18 inches of the ground each year if you want very low plants.

 

When pruning, remember that new growth will emerge 3 to 4 inches below where the limb is cut. Avoid cutting back large limbs and leaving stubs, because an abundance of new growth will emerge near the cut, looking like pom-poms on stalks. Not only is this unnatural in appearance, but this thick, dense growth will be more susceptible to aphids.

 

Diseases

Several diseases occur on crape myrtle including powdery mildew, leaf spot, root rot and sooty mold. Powdery mildew is the most widespread and serious disease. Powdery mildew typically develops in late spring and fall and is associated with warm day and cool night temperatures and high humidity. Leaves and flowers are heavily coated with a white powdery mold that is damaging to new growth. Infected flower buds may not open, and severely infected leaves and buds often drop early.

Another very damaging disease is a leaf spot caused by the fungus Cercospora lythracearum. Spots develop in summer during wet, humid weather. Large, dark brown spots develop on lower leaves and progress upward through the plant. Infected leaves turn yellow around the spots and drop prematurely. Sometimes even one spot will cause a leaf to drop on susceptible cultivars and can cause significant defoliation prior to frost.

 

Sooty mold is an unsightly superficial, dark brown or black coating on leaves and stems that can be removed by rubbing. It is the result of a fungus growing on honeydew excretions made by insects such as aphids, which are the most serious insect pest on crape myrtle. Sooty mold usually causes little direct damage, but it can cut vigor by reducing photosynthesis in the leaves.

 

Powdery mildew and leaf spot and sooty mold can be controlled by applying fungicides when the diseases are first noticed. GreenLights Neem Oil is generally a very effective organic fungicide. Contact the plant specialists at Star Nursery, or the Cooperative Exchange Master Gardeners for other recommendations.

 

Root rots can be prevented by growing plants in well-drained soil, and avoiding the practice of frequent watering.

 

Irrigation & Care You may have noticed many Crape Myrtle with burned tips on their leaves during the heat of the summer. This is usually caused by a small root system. Crape Myrtle becomes a large shrub, and as such needs a large root system to support it during the heat. As your plant matures, simply add more emitters away from the trunk, and make sure that you water slowly and deeply. Shallow frequent watering does not develop the kind of roots that this plant needs. Fertilization is also important to get that crop of flowers you want. Don't forget to fertilize frequently.

 

 

 

 

 

 

 

 

Copy Provided courtesy of Star Nursery


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