Crape myrtle shrubs love the hot days of summer, and after the nice rains of June, they are producing a spectacular show across Oklahoma this year. I truly believe they should be our state shrub and some community should plant them extensively and then host a big crape myrtle festival.
Crape myrtles bloom for many weeks starting in late June, often putting on a colorful flower show into early fall. There are dwarf varieties that only grow 2 to 6 feet tall and the more common semi-dwarf varieties that are tall shrubs or even small trees of 7 to 15 feet tall. They are beautifying up the Oklahoma landscape with colorful clusters of light to dark pink, red, lavender, white or variegated flowers.
Most of the newer varieties are mildew resistant and experience few pest or insect problems. Some of the older varieties still have a problem with powdery mildew, which looks like a white powder over the foliage, limits photosynthesis and may require use of a fungicide.
There are hundreds of varieties of crape myrtle, so select one that will bloom the color you want and grow to the size that fits where you are planting it. When space allows, crape myrtle add even more impact when planted in groups of three or in rows or at the corners of a property or building. They are a deciduous shrub and will drop their leaves after the first hard freeze but the bark on the trunks is quite interesting and attractive to add excitement to the winter landscape.
Many breeders and nurserymen around the United States are working to add even more colors and growth styles to the crape myrtle catalog. The best of those breeders is right here in Oklahoma.
Carl Whitcomb, formerly of Oklahoma State University and now with Lacebark Publications, makes tens of thousands of crosses each year and then grows out the seedlings in his quest for the next great crape myrtle. He has already introduced many exciting new varieties to the national market from his breathtaking crape myrtle fields at Stillwater.
You can plant new container-grown crape myrtle even in the summer heat as long as you will be faithful with your watering. It is always a good practice to mulch summer plantings with a thin layer of bark or hull to help reduce watering and to cool the soil.
Crape myrtle is only one of many plants that actually like and thrive in the hot weather as long as they get sufficient water.
Many pests and insects also do well in the heat and are exploding in population. In the last couple of weeks, we have seen lots of bagworms, armies of grasshoppers, spider mites, squash bugs and caterpillar damage. Animal lovers are dealing with fleas and ticks. Visit your local nurseryman or garden center to identify your problems and to select the control that works best for you. You can choose to share your crop or landscape with these invaders, provide physical control by hand picking or trapping the pests, release beneficial insects or use an organic or chemical control.
Weeds also love the extra rain these last few weeks and the summer heat. You need to limit the weeds by hand pulling, mulching to reduce the weed population or selective use of herbicides to limit the weed competition with your desired crops. It is years like this that help gardeners understand why farmers spend and apply way more herbicides or weed killers than insecticides or fungicides.
Rodd Moesel serves on the Oklahoma State University Agriculture Dean’s Advisory Committee. He is a former president of the Oklahoma Greenhouse Association. Email garden and landscape questions to firstname.lastname@example.org.