How to Plant, Grow and Care for Crape Myrtles

Crape Myrtles (or Crepe Myrtles) have become the most popular ornamental trees in the Southern United States. Their large, colorful clusters of long-lasting blooms line many a street here in my hometown of Tallahassee, Florida.

In addition to their spectacular floral display in the summertime, they are also known for having unique and beautiful peeling bark. The bark on many varieties is known to shed mid-summer, revealing a bright cinnamon orange mingled with the faded, silver grey of the previous year’s bark.

Asia and Australia are the native home of these pretty, flowering trees. In India, they are used as food for moths that produce silk. From Asia, they made their way to England initially, before being brought to South Carolina in 1786.

Legend has it they were sent to the private gardens of two Founding Fathers by the French explorer and botanist, Andre Michaux. Michaux planted the trees in his yard in Charleston, and they quickly became a staple in the city.

These trees make wonderful focal points in the landscape, as well as beautiful hedges, and attractive container plants. A Crape Myrtle screen is a stunning spectacle in the middle of summer. These plants also provide a lot of food for pollinators in the summertime when few flowering trees are in bloom.

Classification

Crape Myrtles are mainly deciduous shrubs and trees. They come in a wide variety of colors including white, red, pink, lavender, and purple. There are about 50 species of these plants, that range in size from less than 10’ tall for dwarf varieties, to over 40’ tall for some larger species.

Among the 50 species, only a few are commonly grown in gardens. Not to worry though, there is a great deal of variation among them in terms of size and flower color. Some of the more common and popular species include:

L. Indica

Lagerstroemia Indica is also called the Common Crape Myrtle, as it is the most popular species in the United States. This winner of the Royal Horticultural Society’s Award of Garden Merit is known for its excellent cold tolerance and a wide variety of flower colors.

It is root tolerant to zone 5, but when kept in this zone it will act as a perennial, dying back to the ground in winter, so it does not grow to its full height. In zones 6-9 this species can reach heights of 20’ tall, and a similar spread. They are fast-growing and very heat and drought-tolerant.

L. Fauriei

This larger species is native to Japan and is commonly referred to as the Japanese Crape Myrtle. It has excellent cold tolerance and has been hybridized many times over with L. indica to increase the cold hardiness of the latter. Fauriei tends to be the tallest species, growing to 25’ and taller.

These trees have stunning bark in shades of maroon, grey and brown, and in the fall their foliage turns brilliant red and orange. Its flowers are white and plentiful and bloom from early summer through early fall.

L. Limii

This small to medium-sized species is not typically planted on its own, but rather, it is used extensively in hybridization. It has very desirable bark coloration with a lovely burgundy color revealed when the older bark peels away.

It is also used for its attractive flower colors, which range from pink to dark red.

L. Subcostata

Subcostata is also rarely planted for ornamental purposes, although it is an attractive tree. It does not flower as prolifically as the others.

Its blooms are pale pink to white, appearing in clusters of just 5-6 flowers as opposed to the large clusters of the more popular species. It has attractive bark, stands rather upright, and has a nice wide canopy.

Planting

Many people purchase their Crape Myrtles in the summer so that they can see the true color of the blooms. However, the best time to plant is in the late fall to early spring, when the trees are dormant. If planted in the summer, your tree will likely need extra watering to help it survive the heat.

When choosing a planting location, it is important to take the mature size of the tree into consideration. Larger species will need a bit of space to spread, while dwarf flowering varieties may only grow to be medium-sized shrubs. Choose a spot that gets plenty of sun and has proper drainage, as this will help avoid root rot.

How to Grow

Newly planted Crape Myrtles will need to be watered deeply, every day for the first week and then 3x per week for the following six weeks. If planting in summer, in a warm climate, expect to continue watering until the weather cools and the tree goes dormant.

Light

Crape Myrtles like a lot of sunlight. They will thrive in 6 or more hours of direct sun daily. Trees planted in the filtered sun will still produce some blooms, but if they are planted in the shade, they will not flower as prolifically, if at all.

These plants are heat lovers, and once established they can tolerate quite a lot of sun, even hot afternoon sun. A few hours of shade daily will not do any harm, but 6+ hours of bright sun, daily, is ideal.

Water

Once mature, a Crape Myrtle is rather drought-tolerant. In fact, once these trees are established, you are unlikely to need to water them except in times of extreme drought.

They need at least one inch of water per week, on average, if they aren’t getting this in rain, it is a good idea to water them deeply once per week in times of little rain. They like soil that is moist, but not soggy or swampy.

Your soil will play a role in how much supplemental water your Crape Myrtle needs, and trees planted in sandier soils may need to be watered more often.

Sand drains very quickly and tends to heat up more than other soil types. The combination of these things means that a those planted in sandy soil may need more water than one planted in clay or loamy soil.

Likewise, the age also determines how much water it will need. The soil around a newly planted tree should not be allowed to dry out completely. For 3-6 months depending on the time of year it was planted, a Crape Myrtle will typically need some supplemental water unless it is getting several inches of rain weekly.

Soil

Crape Myrtles prefer slightly acidic to acidic soil with good drainage. They are tolerant of many different soil compositions including sandy soil and clay-heavy soil. They thrive best in average, loamy garden soil, but as long as the drainage is good and they get enough moisture, they are really quite versatile.

To raise the acidity of your soil, you can add organic matter in the way of fallen leaves, pine needles, or pine bark mulch. Soil acidifiers are also commercially available and work very well. The pH should ideally be between 5.0-6.5.

Climate and Temperature

Crape Myrtles are hardy in zones 7-10, although there are a few varieties that will survive the cold temperatures in zone 6. In general, they are cold tolerant down to a range of 0°-10°F, which is typical of zone 7.

There are ways to grow these pretty trees in zone 6 and even in zone 5 in a container if you can be vigilant.

If you want to plant in zone 6, providing it with some shelter will help it to get through the winter. While it will need to be in full sun for the heat, giving the plant some shelter from freezing winds is a necessity.

Covering during particularly cold weather is also a great idea. A nice thick layer of mulch makes for good root insulation in colder climates as well.

Another option for zones 6 and north is to grow Crape Myrtles as a perennial. This works best with dwarf varieties, as they will die back to the ground in the winter and then regrow in the spring.

You will not ever have a full-sized tree this way though. Some of the smaller varieties can also be grown in containers and brought indoors for the coldest months.

Fertilizer

Crape Myrtles like a lot of fertilizer, they will use up just about everything you give them. As soon as the leaves begin to show up in spring, start fertilizing. A balanced fertilizer such as an 8-8-8 or a 10-10-10 will work great for these plants. A slow-release formula is even better.

Throughout the spring and summer, lightly fertilizing every 2-3 weeks will help boost new growth. Just don’t go overboard, or you will end up with lots of new growth but fewer flowers. This is particularly important for mature, established trees.

The larger the tree, the more fertilizer it will take in. Stop fertilizing when the flowers fall, as new growth can be damaged by freezing weather.

Pruning

Now I can’t speak for any other places, but where I come from, pruning is a topic of great controversy. There are a few different schools of thought on how much is too much to cut off, and what is not enough.

It really all depends upon what appearance you want to have, and how much of the tree’s integrity you are willing to sacrifice to achieve that look.

I won’t pretend to judge anyone who commits Crape Murder, I’ll just say this; Hat Racking, as my mother calls it, does damage the structural integrity and therefore, the strength of the tree.

If you’re unfamiliar with this practice I am alluding to, there is a pruning method whereby the top of the Crape Myrtle is chopped off entirely, the resulting appearance is something like a bundle of kindling or a witch’s broom.

If you’re not familiar with this practice, it probably sounds hideous and senseless. The reality is, this method actually creates a stunning effect in the summer. The result of Crape Murder is a tree that resembles a palm of sorts.

The new growth resembles a fountain of new, uniform branches, each with a cluster of flowers at the end. It’s quite beautiful. While it is obviously not without its merits, as I mentioned, this method of pruning damages the tree’s structural integrity in the long term.

The best way to prune is to wait until there is no chance of a frost and trim in the early spring before foliage appears.

Only trim what is necessary to shape the tree. Contrary to popular belief, pruning is not necessary for the production of flowers. Deadheading is also, not necessary. The greatest factor in flower production is the amount of sun the tree receives.

Maintenance

To keep your Crape Myrtle in tip-top shape, make sure to fertilize regularly during spring and summer, and a layer of pine bark mulch before the winter will help insulate the roots, hold in moisture during drier months, and lower the pH of the soil.

Pests & Diseases

Crape Myrtles are surprisingly resistant to disease, but there are a few insects to worry about. The prevalence of the Myrtle Bark Scale has greatly increased in recent years and is the greatest threat to these plants.

Caterpillars

Crape Myrtles are larval food for more than one type of insect. The only one to worry about is the stinging pus caterpillar. These are the larvae of the Southern flannel moth. It looks like a tiny toupee working its way across leaves. These guys will mind their own business as long as you do as well.

These guys are very toxic if touched, so if you see them, avoid them. It has venomous barbs along its back, so even brushing up against one can result in a serious reaction. I’m typically not an advocate of insecticides, but if I saw these guys show up in my yard, I might give it some consideration.

Crape Myrtle Aphids

The crape myrtle aphid is the only aphid that feeds on myrtles, and it shows up during the summer to suck the sap from new growth. They leave behind a sticky mess that causes sooty mold to grow, so aside from the damage that they cause to leaves by way of draining the nutrients, their excrement is a second issue.

These small yellow-green insects like to congregate on the underside of leaves. The younger the leaves, the better, as the flesh is thinner and easier to pierce.

If the infestation is minor, spraying them with a hose or pinching off the affected stems should be sufficient. Aphids have lots of natural predators, so they don’t tend to be enough of an issue to kill an established tree. Insecticidal soaps work as well.

Crapemyrtle Bark Scale

These insects are a relatively new issue outside of Asia, but they are gaining a foothold here quickly. Scale are tiny insects that pierce the flesh of new growth and feed on sap, just like aphids. Like, aphids they also leave behind a sweet, sticky excrement called honeydew that encourages the growth of mold.

A heavy infestation of scales will deplete the tree of nutrients and can cause the dieback of branches. Scales form a waxy coating that protects them from most pesticides, during the summer.

The best time to treat is early fall after their waxy coat has dissolved and they have newly hatched larvae. In the Spring, before the new scales have formed their covering is another suitable time to treat with horticultural oils and insecticidal soaps.

Japanese Beetles

Japanese beetles can be damaging to both the roots and foliage. The larvae live in the ground and munch on new roots, and the adults make quick work of leaves, leaving only the veins behind.

They can be taken care of using neem oil usually. In extreme cases, chemical pesticides may be necessary. Always treat in the late afternoon so that pollinators do not come in direct contact with freshly sprayed chemicals.

Sooty Mold

Sooty mold is the resulting issue caused by the honeydew excreted by certain insects. This dark moldy substance interferes with photosynthesis, which leads to overall poor health for the plant.

It’s a pretty big hassle when this mold is all over the plant, so catching it, and eliminating the issue early is imperative. It must be wiped away by hand, which is time-consuming, to say the least.

Powdery Mildew

Powdery mildew is a fungal disease that can affect Crape Myrtles. This white fungus grows on the top of the leaves. It will cause the growth of your tree to be stunted and can interfere with the development and blooming of flowers.

The spores are carried in the wind, so it is very difficult to prevent, but planting in the full sun seems to help prevent the spread of this disease. Pruning overcrowded areas can also help by increasing air circulation in the interior of the tree.

Popular Varieties

There are a number of popular varieties you can plant, depending on your local climate. Let’s take a look at some of the most commonly planted varieties readily available to most gardeners.

Apalachee

	botanical name Lagerstroemia Indica x Fauriei ‘Apalachee’
	sun requirements Full Sun
	height 10’-20’ tall
	hardiness zones 7-10

This medium-sized Crape Myrtle has the signature peeling bark of many Myrtles. The bark peels in midsummer to reveal a striking, cinnamon color.

The tree produces large panicles of lavender flowers that are lightly fragrant and last through summer and into the fall months. The lavender is a lovely contrast against dark green foliage. This variety turns orange and deep red in the fall before going dormant.

Cheyenne

	botanical name Lagerstroemia ‘Cheyenne’
	sun requirements Full Sun
	height 10’-25’ tall
	hardiness zones 6-10

Cheyenne is another mid-sized variety and this one has great cold tolerance. The foliage emerges in spring with a burgundy tinge and turns back to this shade in the fall before going dormant.

In between, Cheyenne produces large panicles of crimson flowers with ruffled edges. This pretty plant provides 3 seasons of beauty.

Natchez

	botanical name Lagerstroemia ‘Cheyenne’
	sun requirements Full Sun
	height 20’+ tall
	hardiness zones 7-10

This is a larger variety of Crape Myrtle tree with snowy white clusters of blooms. The overall appearance of a white flowering Crape Myrtle is lacy and gorgeous in summer.

Natchez has bark that peels mid-summer for a cinnamon orange pop turning to silver just in time for the foliage to turn bright copper in the fall.

Osage

	botanical name Lagerstroemia x fauriei ‘Osage’
	sun requirements Full Sun
	height 10’-20’ tall

This fast-growing Myrtle produces an amazing amount of bubblegum pink blooms throughout the summer. The signature peeling bark on this tree is a maze of cinnamon and burnt sienna making the tree a beautiful addition to the garden even when it is dormant.

It is a mid-sized variety and puts on a beautiful show of crimson and burgundy before winter.

Pink Velour

	sun requirements Full Sun
	height 10’-20’ tall
	hardiness zones 7-10

Pink Velour is the quintessential Crape Myrtle, a tree with large, pink flowers. It is very drought tolerant and resistant to disease, in addition to its lush, green foliage and large panicles of bright pink flowers. This Myrtle attracts a lot of attention, and not just from human observers.

The pollinators will go crazy for this pretty plant. The leaves range from wine red to purplish green, adding even more interest and intrigue to this variety.

Powhatan 

	botanical name Lagerstroemia indica ‘Powhatan’
	sun requirements Full Sun
	height 10’-20’ tall
	hardiness zones 7-10

Powhatan is a mid-sized Crape Myrtle with lovely lavender-pink panicles of flowers that cover the tree in summer. This variety is fast growing, reaching its final height of about 20’ in a handful of years and living for about 20 years total.

The foliage appears as orange in the spring and turns copper in the fall, making this a plant with three seasons of interest.

Tuscarora

	botanical name Lagerstroemia indica x faurlei ‘Tuscarora’
	sun requirements Full Sun
	height 20’+ tall
	hardiness zones 6-9

This larger Crape Myrtle produces a profusion of coral-colored flowers in summer. It has good cold tolerance and wonderful, colorful bark.

This is a particularly hardy variety that will thrive in most conditions and can be pruned into a large shrub, or a tall, elegant tree. It is disease resistant and truly has all of the best qualities of a Crape Myrtle.