Crape myrtles are one of our most popular blooming shrubs in North Texas! The “original” Indica crape myrtles are native to China and the first records of it being brought to the United States date back to the late 1700’s. These crape myrtles were pretty, usually left unpruned in any way, but were very prone to powdery mildew. In 1956, a second major variety of crape myrtle, the faurei, was introduced here from Japan – these almost pure white types had wonderful exfoliating bark and excellent disease resistance. The hybrids bred from careful crossing of these two types at the National Arboretum, university research programs, and good old fashioned entrepreneurs (commercial growers) around the country since then make up some of our most popular named varieties today, with an enormous color palette of whites, pinks, lavenders, and reds and heights from as small as 2 feet to as large as 30 feet in upright, rounded, and weeping habits. Add to this the fact that most crape myrtles bloom for around three months a year, and it’s safe to say that as long as you have a nice, sunny area, there’s probably a crape myrtle that can grow to fit your landscape needs!
Keep these considerations in mind when choosing your ideal crape myrtles:
• Your bloom color preference
• How tall and wide you want it to be at maturity
• What shape you want it to have
• All other things equal, which choice has better disease resistance
The color of the crape myrtle is what most folks look for first! There’s a wonderful selection of just about every kind of white, lavender, pink, purple, red, and variation on these colors. Some types are even bi-color (two colors on the same blossom, typically pink and white), though stress may cause them to come out solid pink. Determine the color you’re interested in, then look at the following important factors.
Crape myrtles are roughly grouped into the following major height categories:
• Miniature – usually weeping types, typically 3′ or shorter
• Dwarf – 3-6′ height range, generally upright or rounded
• Intermediate – typically rounded or upright plants, 6-12′ in height
• Tall – often called “standard”, not to be confused with a single trunk, 15’+
Choose your crape myrtles based upon what their mature height will be. Never chop a taller variety you like the looks of to control the height!
The shape of the plant is another consideration. “Upright” or “vase” shaped crape myrtles are taller than they are wide. “Rounded” or “globose” types are as wide at the top as they are tall, and you should plan for this accordingly. “Spreading” types are wider than they are tall. “Weeping” types are generally miniature, and are left alone to develop their natural form. Most crapes used in residential landscapes are upright or rounded.
The last consideration is the natural disease resistance. With proper planting and care you can avoid most powdery mildew issues before they start; but very rainy weather or cloud cover for extended periods can encourage mildew growth. Some types of crape myrtles are simply more resistant to this disease, and if you’ve two choices that will fill your height, shape, and color requirements, you should use the type with the best disease resistance.
Where you place your new crape myrtle makes a huge difference to the overall health, vigor, and beauty of your mature plant! Follow these tips for the best success:
• Plant in full sun (at least seven hours of direct sun). Crape myrtles will live in less light, but they’re never as vigorous or full, and they’re more prone to leaf diseases than the exact same plant put in a very sunny area.
• Select a site where your crape myrtle will have several feet of spacing all around it. Don’t plant next to walls, fences, large shrubs, etc. Good spacing will provide excellent air circulation which will reduce mildew issues. It’s fine to plant some smaller perennials or shrubs underneath tree-form crape myrtles as long as there is sufficient airflow. Proper spacing will also give your crape myrtle room to grow to its full mature height and width.
• Crape myrtles look beautiful around pools, but they do lose spent blooms.
• When planting multiple crape myrtles, mass planting the same color makes a much larger impact. Still maintain the recommended distance apart for the plants’ mature size.
Planting a crape myrtle is not any different than planting any other common tree or shrub in North Texas. In a prepared bed, plant it so that the soil line of the top of the root ball in the container is slightly above grade. In a pocket planting situation, dig a hole roughly twice the diameter of the root ball, amend the existing native soil with a mixture of compost and expanded shale, and plant the root ball slightly above grade.
Add a 2″ layer of your favorite mulch that is organic, can rot, and won’t float. Good choices for this purpose are hardwood mulch, cedar mulch, cypress mulch – these aren’t the only choices, but they are good ones. Water your newly planted crape myrtle heavily at planting, and heavily again for the next two days, then begin your normal maintenance routine. It’s technically possible to overwater a crape myrtle, but it’s not easy!
Crape myrtles need far less pruning than most people provide! Here are the Do’s and Don’ts when it comes to crape myrtle pruning:
• Remove entire limbs or branches cleanly at the ground or the next limb as you wish to improve the form of the crape myrtle. Limbing up your crape myrtle to expose clean trunks is OK.
• Remove any cracked, damaged, tangled up branches or trunks, at the next healthy branch, trunk, or ground level. Leave nicely spread, open trunk structures.
• Chop back your crape myrtles, ever, ever, ever! If anyone claims to be a landscape professional or arborist and they want to do this to your crape myrtle, it’s a good indicator they aren’t professional! This is known in the industry as “Crape Murder” because of the damage it does to the form of your healthy plant. If your crape myrtle is too tall for where it is planted, it’s simply too tall and needs to be moved to a better location next winter, or simply removed, to be replaced with a crape myrtle of the proper mature height and width.
• Tip off seeds to clean the plant up. You may, if you wish, remove spent seeds as long as nothing larger than the diameter of a no.2 pencil is being cut off, but it’s not necessary or even helpful for the blooming of the crape myrtle to do so. Clean off seeds if you just can’t stand them, but otherwise, it’s better to simply leave the seeds alone. The crape myrtle will clean itself off in time.
The maintenance of a new crape myrtle is not difficult, it just requires due diligence! Newly planted crape myrtles like lots of water. If the crape myrtle is planted in the cool season, water it well. If the season is hot (say, you wait until summer to plant your crape myrtle so you can really see the color instead of the tag color), water a newly planted crape myrtle even more! Well established crape myrtles are reasonably drought tolerant but new ones need the waterhose, plenty and often. The sprinkler is not enough.
Feed your crape myrtle root stimulator and our Covington’s Tree & Shrub fertilizer for the best success, and mulch the new plant with a good 2″ or deeper layer of your favorite mulch. Mulch degrades over time and thus you will need to add mulch at least once a year to maintain a nice, thick layer of mulch over the root zone.
NOTE: With sprinkler systems, avoid creating problems you don’t need. The risers on many sprinkler systems can easily spray the foliage of a young crape myrtle, and this is not desirable. Adjust your sprinkler system to water the soil, not the leaves of your plant. When watering with the hose, the roots are the target. Don’t contribute to disease issues that aren’t necessary.
Once in a while, even the best planted, established crape myrtles can have a health issue pop up. The most common issues are the likely ones – below, the answers to most of the problems that might pop up for you.
• White powder on crape myrtle leaves, and those leaves are twisted and cupped, and some leaves are falling off. This is powdery mildew, treatable with ferti-lome Systemic Fungicide, Daconil or Neem oil. Rake fallen leaves away.
• Sticky residue on crape myrtle leaves, and it is raining under my plant. Aphids on your new growth are causing this. Treat with almost any pesticide, as long as you treat every 3-4 days. Aphids are easy to kill, they just breed fast. Ladybugs work great, too because they eat aphids!
• Small white lumps all over crape myrtle trunks and branches and there is a sticky residue too. This is a new type of felt scale. Treat during the winter with dormant oil; during the summer, treat with Bonide or ferti-lome Systemic Insect Drench insecticides and a summer-weight horticultural oil.
• Black mold all over crape myrtle trunks. You have one of the two above problems, aphids or the scale insect, and the honeydew they leave (read, bug manure) is mostly sugar water. Airborne molds grow in it, and a common one around here is a black mold. It’s harmless, just messy. It will weather off in enough time, but you need to treat the correct insect pest causing the problem.
The above issues account for 99% of the possible problems your crape myrtles will have in our area. There are a few others, but they’re rarely serious. Watch for these and you’ll be fine.
We at Covington’s hope this guide helps you to achieve the best success your crape myrtles.