PROBLEMS CAUSED BY STRESS:
Aphids and powdery mildew are the two most common problems we have in Oklahoma where Crapemyrtles are concerned. Though neither is too serious, both can cause your Crapemyrtle to have an unsightly appearance. If you go a bit south to Texas, you will also find that scale can be an issue. I hope that it does not cross the river.
The aphids and the powdery mildew are more an irritation than a serious problem. Both aphids and powdery mildew are generally brought about because of stress.
Powdery mildew, a fungus that attacks and distort the leaves is caused by a lack of circulation. A lack of proper circulation can be caused by poor pruning techniques as well as the location in which you have planted the Crapemyrtle. This poorly selected location may not allow the leaves to dry out. A couple of treatments of Plant Wash sprayed on the leaves will quickly get things back into check.
Prior to purchasing the Crapemyrtle, read the nursery tag attached to it carefully and look for varieties that are resistant to powdery mildew like ‘Acoma’ (white flowers), ‘Hopi’ (light pink), ‘Comanche’ (dark pink), ‘Zuni’ (lavender) and ‘Tonto’ (red) in the taller varieties. Compact Crapemyrtles, 3 to 6 feet tall, such as ‘Hope’ (white), ‘Ozark Spring’ (lavender) and ‘Victor’ (red) are also resistant to powdery mildew. Unfortunately, the compact Crapemyrtles are not resistant to powdery mildew.
The sticky drippings you often find on your Crapemyrtle is the waste or “honeydew” of small insects called aphids.
These pesky little creatures can be temporarily eliminated with a strong blast of water straight from the garden hose. They will however, come back unless the stress in the tree that brought them to the tree in the first place is not removed.
Proper Planting Reduces Stress Which Will Hold Insects & Disease At Bay:
One of the reasons Crapemyrtle is so well suited to Oklahoma lawn and gardens is that it can be a low-maintenance plant. The best way to ensure this is to choose the cultivar that best suits your landscape needs before planting. Choosing the proper height of plant, its proximity to water and the amount of sunshine available will all help determine the Crapemyrtles impact on your lawns/beds appearance.
1. Pick The Proper Size Of Crapemyrtle
There are many cultivars of Crapemyrtle to chose from, not only different colors but different plant sizes. The dwarfs range from 2-3 feet up to 6 feet tall while the semi-dwarf tend to be 7 to 15 feet. It is the great range in sizes that make it easy to choose the right size plant for a particular space. Severe pruning and topping is not the preferred method to ensure that a plant will fit into the desired space. The preferred method is to buy the right plant to begin with by looking at its size when mature.
2. Dig An “Ugly” Hole And Leave The Root Flare Exposed
When digging your hole, be sure that it is an “ugly” hole with jagged sides. Since one of the most common causes of stress in trees is being planted to deeply, make sure the tree is planted with the root flare exposed and visible above the ground as shown in the photo below.
Do not to plant your Crapemrytle like the ones in the 2 pictures below.
3. Do Not Backfill Your Ugly Hole
Nothing should go into the planting hole except the soil that you dug out of the hole. Putting amendments or backfill soil in creates a “bowl” effect in our Oklahoma clay. This situation makes it difficult to avoid having too much or too little water around the plant’s roots. Amendments should go on the surface of the soil around the tree, but not up the trunk of the tree.
4. Proper Watering and Sunlight
Stress in your Crapemyrtle can be caused by too much or too little water. To prevent this, note whether the planting spot you have chosen is convenient to water. If it is not, then watering turns into a chore and the plant will suffer. If on the other hand, the Crapemyrtle has been planted in a bed with plants that need moist soil the Crapemyrtle will become stressed.
Crapemyrtles like full sun light and plenty of it. Proper sunlight will produce not only a healthy appearance but it will also reduce the chances of powdery mildew and aphids.
5. What Chemicals And Lawn Fertilizers Might Do
Stress can also be brought about by broadcasting excess fertilizer up to the Crapemyrtle as you fertilize your yard. Even broadcasting a weed and seed on your lawn can have a negative impact on your Crapemyrtle.
Soil compaction and soil contamination caused by herbicides and other toxic chemicals will also cause undue stress and make the Crapemyrtle susceptible to insects and disease.
Don’t forget to feed and water the birds!
The “Original” Red Dirt Gardener