Crepe Myrtle Diseases

The best flowering tree in the world is the crepe myrtle. It is a native tree of China and Korea and some parts of Australia. The crepe myrtle trees are available in different colors and it has an attractive bark. You can grow crepe myrtle trees for ground cover, as a shrub or like a tree. It is a deciduous tree that grows long-lasting flowers. The flower colors range from white, red, lavender and pink. Crepe myrtle trees bloom in early summer to fall. The bark tends to peel off and give the trunk beautiful shades of gray and brown. In fall the leaf color changes from green to yellow, orange and red. The older varieties of this tree were susceptible to many diseases. Some of the crepe myrtle diseases are discussed in the following paragraphs. But, before we learn about the crepe myrtle diseases, let's have a look at how to grow crepe myrtles.

How to Grow Crepe Myrtles
Crepe myrtles are known as the 'lilac of the south'. These trees are very easy to grow in zone 5 and above. You need to choose a location of well-drained soil that basks under full sun. Let us learn in detail how to grow crepe myrtles. Make sure you plant the tree in a location that receives full sun as shady locations can lead to many common crepe myrtle problems like mildew. The planting hole that you dig in the soil should be of the same depth as the container or nursery holding the sapling. Very gently and carefully remove the sapling from the container and place in the planting hole. The roots should be spread out in the hole. Then fill back the planting hole with soil and add water.

You can even add 2 cups of organic fertilizer to the base of the tree slightly above the root zone. Cover the base with mulch about 3 inch thick. This will help retaining the moisture in soil. You should be pruning crepe myrtle trees in such a way that they grow at least more than 2 trunks. Remove the spent flowers once or twice during growing season. Do not shear the tree from the top as it will make it vulnerable to common crepe myrtle problems like insect damage.

Common Crepe Myrtle Problems
Many first time crepe myrtle growers tend to plant the tree deep into the soil. This leads to lack of oxygen for the root ball. You should make sure the root ball is almost in level with the soil. This will help it get oxygen from the atmosphere and grow well. Some of the common crepe myrtle problems arise when crepe myrtle pruning is carried out heavily. A tree with heavy pruning tends to focus all its energy and nutrients on the new leaves and branches. The tree is left with no energy that helps it expand and bloom more flowers.

Apart from lack of oxygen, a crepe myrtle tree cannot survive a long dry period. You need to provide it with enough moisture during dry season or drought. Therefore, it is important you mulch around the tree to retain moisture around the soil.

What are Common Crape Myrtle Diseases
Before one brings home a crepe myrtle, it is important to know about what are the common crape myrtle diseases. This will help you take better crepe myrtle care. Some of the common crape myrtle diseases are as follows:

Aphids
The common garden pests that infect crepe myrtle are aphids. They are very common on flowering plants and fruiting trees. Aphids are dull yellow in color that suck out plant sap from tender leaves. After consuming the sugar rich sap, they excrete yellow liquid called honeydew. The leaves that are attacked by these tiny pests develop yellow spots mostly on the undersides. These leaves tend to dry out and wilt. Sometimes certain aphid species cause galls (swelling of plant tissues) on crepe myrtle that is round or spindle-shaped. These galls are full of aphids in different stages of their life. When the crepe myrtle tree has a heavy infestation of aphids, it causes a lot honeydew to accumulate on the tree. This attracts other pests, insects, ants, wasps, mold fungi and flies. Thus, it is very important that you take immediate steps for controlling aphids. You need to use a forceful water bath or a pesticide spray to get rid of aphids. Apart from this, you can use lady bugs and lace wings to control these aphids. These insects eat up the aphids and help control their growth.

Sooty Mold
Sooty mold indicates the presence of insect infestation. This is a charcoal black fungus that covers the surface of leaves, fruits, twigs and branches of crepe myrtle trees. This fungus does not cause any pathogenic problems on the crepe myrtle tree. It gets its nourishment by feeding on the insect honeydew. When these sooty molds grow thick, they cover the entire leaves. Thus, the tree is unable to carry out photosynthesis. Insects that grow on the plant include whiteflies, scale insects, aphids, etc. and produce this honeydew. You need to use insecticide to get rid of insects as well as sooty mold. Also a forceful water bath containing a dishwasher soap mixture will help get rid of the sooty mold.

Cercospora Leaf Spot
Yellow to orange spots on the upper side and whitish gray spots on the underside of crepe myrtle leaves indicate cercospora leaf spots. The yellow spots appear due to the toxins produced by the fungus and the gray white spots underneath the leaf are the fungal spores. This infection is caused by a fungus cercospora beticola. This is a fungal infection that occurs in moist weather. It can cause complete defoliation of the tree and affect growth of younger trees. You need to plant your crepe myrtle tees in areas that receive good air supply. You can use a fungicide to get rid of infestation.

Powdery Mildew
One of the most common crepe myrtle diseases is powdery mildew. It causes white or grayish powdery coat on the leaves. Initially, the infection begins as sporadic, circular, powdery white spots. As the infection spreads, these tiny spots become larger. Soon they form a continuous matt of powdery mildew. This fungal infection does not allow new leaves and flowers to open. It may also lead to a stunted tree growth. If you find few twigs, leaves or branches affected by powdery mildew, prune them immediately. Heavily infected trees needs fungicide for powdery mildew treatment.

Japanese Beetle
The Japanese beetles are another pesky pests that will eat up your crepe myrtle trees. These inch long beetles love to feed on the foliage and flowers of the crepe myrtle tree. You need to get rid of both the larvae as well as the beetles, to save your tree. You can use insecticides and insect traps for controlling Japanese beetles.

These were some of the common crepe myrtle diseases. Generally, crepe myrtles are free from problems. You need to take good care to avoid the common crepe myrtle problems. Hope the above information on what are crepe myrtle diseases has been helpful to you.