Crape myrtles are flowering shrubs or trees, and depending on the variety and climate, they bloom in the late spring, summer or early fall. Deadheading may encourage crape myrtles to bloom a second time later in the growing season. However, do not deadhead crape myrtles too late in the season because the new growth will not have time to harden off before winter and your plant could suffer winter damage.
Wait for an entire cluster of crape myrtle blooms to fade in color.
Clip off the stem just underneath the cluster of spent blooms with a pair of sharp, clean hand clippers.
Continue to deadhead the spent cluster of blooms until midsummer. Do not deadhead crape myrtles any later than midsummer.
Plant crape myrtles in a location that receives full sun. They need full sun exposure to bloom well. Don't plant crape myrtles in the vicinity of taller trees that can block the sun.
Water the crape myrtle abundantly when first planted, to help it establish its root system. During the hot summer months water often so it does not whither.
Apply a 5-10-5 fertilizer designed for flowering trees. Do not overfertilize, as this can lead to production of more leaves and less blooms.
During the middle of the summer, clip any fading blooms on your crape myrtle. Prune the tree in the spring to maintain its shape. During the year, suckers may grow at the base of the tree. Cut these whenever they sprout unless you want your crape myrtle to become a shrub. In the winter, prune the stem tips only.
Remove the limbs of your crepe myrtle that are broken, dead or diseased.
Remove suckers. Suckers are new growth called shoots that grow from the root system.
Remove side branches that are growing beyond the size that you desire for your crepe myrtle.
Remove all branches that are crossing or rubbing together.
Remember to cut back to the larger branches of the bush. Make sure your tools are sharp and in good working order so that the cuts are smooth. Avoid tearing the bark to prevent damage to the bush.
The Cercospora lythracearum fungus causes cercospora leaf spot, while the Erysiphe lagerstroemia fungus causes powdery mildew infections in crape myrtles. Crape myrtle aphids also indirectly cause a disease called sooty mold.
If your tree is infected with cercospora leaf spot, it will have irregular brown spots on the leaves that gradually grow until the leaf turns yellow and falls from the tree. Identify powdery mildew by the cottony white patches that form on leaves and shoots; the leaves may turn brown, curl or prematurely fall. Some diseases are also caused by insects. If you see small yellowish-green insects on your tree or see a sticky residue or black fungus on the leaves, crape myrtle aphids are probably feeding on plant sap and exuding a sticky-sweet liquid that acts as a growing medium for sooty mold.
Treat cercospora leaf spot and powdery mildew infections with timed applications of fungicides. Kill the insects to treat sooty mold by spraying the tree with a steady stream of water to dislodge the bugs or spraying the bugs with an insecticide. When the insects are gone, wash the mold from the plant with a mild solution of water and dish soap.
Choose a site that will receive full sun.
Use a shovel to dig a hole that is two times bigger than the size of the crape myrtle’s root ball. Set the soil aside.
Center the plant by placing the root ball in the middle of the hole. Cover the plant using the soil that was removed. Tamp down the soil with a shovel.
Water the plant thoroughly, allowing the soil to settle around the plant’s roots.
Add a layer of mulch, 3 to 5 inches thick, around the base of the plant to help conserve moisture and to guard against extreme temperatures. Pine bark, shredded leaves or pine straw are all effective and acceptable types of mulch to use.
Continue to thoroughly water the plant weekly (as long as it is not raining) for the first two months following planting.