If the rose is the undisputed queen of the garden, then crapemyrtles are her knights in shining armor, for when summer temperature rise, and the queen goes into seclusion, that’s when crapemyrtles really begin to shine.
“When sustained daytime temperatures are about 85 degrees F or above, and other species are losing their luster, crapemyrtles begin to produce flower buds for their summer show-off period,” said Carl Whitcomb, PhD. and President of Lacebark, Inc., “Once flowering is triggered to begin, on many cultivars, it continues for 100 to 120 days or more.”
Crapemyrtle, Lagerstroemia indica, is a large flowering shrub or small tree native to China, but it is well adapted to Oklahoma and the southern half of the United States. Through hybridization and selection, crapemyrtle developers expanded the genus to include mid-size and dwarf crapemyrtles for smaller gardens.
“It is such a tough and adaptable plant with the capacity to survive almost any conditions except where the temperature gets below about -5 degrees F., ” said Dr. Whitcomb.
According to Dr. Whitcomb, the common name for L. indica should be written as the compound word, crapemyrtle, and not as crape myrtle, because the plants are not related to the myrtle family. He should know. Dr. Whitcomb, who works and resides in Oklahoma, developed many of the new crapemyrtle varieties in the garden marketplace, including some of the most popular like Tightwad Red® and Dynamite®. L. indica is the plant most often grown in the southern part of the United State and is hardy to USDA Zone 7. L. fauriei, the other form, is hardy as far north as USDA Zone 6.
Not only do crapemyrtles have a long bloom period, they have few pests, and the newer cultivars are very resistant to powdery mildew, a disease that plagued older varieties. As a precaution, plants should always be placed in full sun with good air circulation. Fungicides are rarely needed. I have never sprayed my crapemyrtles for disease. In the late spring and early summer, crapemyrtles can be attacked by the crapemyrtle aphid, Tinocallis kahawaluokalani. Aphid colonies congregate on the underside of leaves. They suck sap out of the leaves and young stems excreting a substance called honeydew. Sooty mold can grow on the honeydew giving new plant growth a dark cast. Ladybugs, also known as ladybird beetles, beneficial wasps and other aphid predators help control these pests. Pesticides are more detrimental to beneficial insects than the aphids so they shouldn’t be used. If a large aphid colony attacks plants, a blast from the hose in the morning should eliminate most aphids and give leaves a chance to dry.
Since crapemyrtles bloom on new wood, Dr. Whitcomb suggests that the old idea of pruning heavily each year should be abandoned.
“Where the severe pruning of crapemyrtles began and why is unknown. the hype has been that you get more flowers. That has not been proven to be true in my research and similar research at the University of Florida.
“Pruning is always stunting because a plant runs on energy and leaves are the manufacturing sites of that energy,” he said, “Anything you do that reduces the number of leaves is stunting compared to a plant that has not been pruned.”
Instead, he suggest planting the right plant for the right place. If you want a dwarf red crapemyrtle, plant one like Tightwad Red® that grows to four feet tall or less. For a taller variety, plant Dynamite® or Red Rocket® that grow to fifteen fee or more. It’s fine to clip oof old flowers and seed capsules, but Dr. Whitcomb is working on creating sterile plants that increase flower producton and reduce the need for pruning.
The Quest for Red
When Dr. Whitcomb left Oklahoma State University in 1985, he selected approximately forty species of plants he believed had promise, but also need improvement. His quest for red flowering crapemyrtles was motivated by a scientific paper he read which concluded that red flowers were highly unlikely due to the lack of proper pigments in crapemyrtle and althea flowers Dr. Whitcomb’s first parent crapemyrtle, from wich all of his plants are descended has medium pink flowers. After generations of selecting and saving seeds from some of the darker pinks he began to see more and more reds. Not only did Dr. Whitcomb select for red flowering plants, he also selected for powdery mildew resistance. He has achieved both and now has several red flowering crapemyrtles, including Dynamite®, Red Rocket®, Siren Red® and the dwarf Tightwad Red®. Each plant has its own distinctive red hue and growth habit.
“The gene pool in L. indica is huge and has lots of variations yet to be revealed. I am pursuing a number of variations, and each year I find fascinating new genetic expression,” said Dr. Whitcomb. He is particularly excited about one of his newest plants, Rhapsody in Pink® that has red-wine foliage and light pink blooms.
“Most crapemyrtle cultivars provide a roller coaster of blooms. The flower show typically begins in late June or early July, then a lull while the seeds mature, then another bloom period and so on,” he said, “With Rhapsody in Pink®, this new sterile cultivar produces a panicle of blooms, then another and another.”
Bustani Plant Farm, Stillwater, Oklahoma;
Bob’s Scott’s Nursery, 10116 West Wilshire Boulevard Yukon, OK 73099;
Sooner Plant Farm, located in Northeastern Oklahoma; and
TLC Nursery, 105 West Memorial Road, Oklahoma City, OK
This article was published in July 2009–I think. It was reprinted with permission from Oklahoma Gardener magazine. In the last few years, many other worthy crapemyrtles have hit the marketplace including miniature and weeping forms. This article highlights my interview with Dr. Whitcomb who is a great resource for our state.
What an enjoyable read! Here in central CT, zone 6b, I’ve been successfully growing both ‘Dynamite’ and ‘Cherry Dazzle’ for at least five years. They grow as multi stemmed shrubs and occasionally die back to the ground in the winter. During the winter of 2010-2011, ‘Dynamite’ was almost taken out by voles but apparently they left just enough root for it to survive because it’s back and getting ready to bloom.
Happy Birthday, BTW and welcome to the SGAFO!
Toni - Signature Gardens
Are y’all having any trouble with the bark scale? It is getting really bad in North Texas. It popped up here about 4, 5 years ago. Twice-stabbed lady bugs will take care of it, but that type of lady beetle is far and few between. It makes those beautiful trunks very unsightly. There are systemic chemical controls, but I have been hesitant to use them at this point, hoping to encourage biological control with the lady beetles. I use Pink Velour on landscape jobs often because it is a nice size for homeowners.
I argue enough with people who spell it “crepe” and not crape. Now I have to learn to spell it as one word.
Donna@Gardens Eye View
A lovely plant I keep reading about that will not like my zone 5 garden…I can still look in awe through your eyes.
I have long envied Southern gardeners for being able to grow these beautiful trees. This was such an interesting and informative post, Dee; I had no idea, though, that crapemyrtles (thanks for the proper spelling!) would bloom for a 100 days or more. Now I really want one! I am on the edge of zone 6 for the L. fauriei, though most winters we do get below -5 degrees at some point. I wonder if I should take a chance?
Dr. Whitcomb was my professor for Plant Identification while I attended Oklahoma State. At that time he was taking Crape Myrtle seed and radiating it and forming new varieties. Always looking for the elusive red crape myrtle. Of course you can’t talk to Dr Witcomb without discussing his root control bags for nursery stock and of course his favorite tree, Lacebark Elm. And what OSU graduate in horticulture or Landscape Architecture doesn’t have his book Know it and Grow it. Ha!
He is one of the most humble yet energetic and passionate horticulturist I have ever had the pleasure to meet and study under. Bravo!
What a super informative post. I’ve been reading about Dr. Whitcomb and his work concerning non seeding varieties. I have ‘Pink Velour’ (in my daughter’s garden) but it is not yet big enough to see if it will self seed. I think that is my biggest complaint about them as I have half a dozen coming up in my garden. It’s so cool to see some of his hybrids in your garden. Love these knights!
Diana/Sharing Nature's Garden
Dee – You have a lovely collection. I have a row of 6 along our driveway and they are towering now – a beautiful white canopy all summer long. I didn’t plant them, and wouldn’t have planted white, but now I love them. Your tightwads are wonderful – I know there are lots of mini varieties and I’d like to try more of them in the garden. We usually have the best luck here in Central Texas with those with Indian names — they seem most adapted and successful in our climate.
Diana, they sound beautiful. I can just imagine all that frothy white. I’ve bought two new crapemyrtles this year. They are miniatures. Can’t wait to see how they perform here.
What an ode to crepemyrtles. Here in Kansas before our no winter, you could expect the plant to be burned to the ground only one time out of four years. But when she is taken down, get out of her way because she’s like a women scorned in response. Loved the cool patterns on the bark back home in Sydney.
Thanks Patrick. I love my crapemyrtles because they offer so much for so little. They are basically fuss free and bloom all summer here. Goodness knows, in our climate, we need something easy and pretty too.~~Dee
Janet, The Queen of Seaford
We bought Dynamite in Virginia and love its red blooms. It bloomed a little later, as well as later foliage leafing out. My new favorite is Delta Jazz. I really like the ones with the burgundy foliage. Good information about this great long blooming beauty.
Janet, Dynamite does bloom a little later. I’d forgotten about that. I would like to grow Delta Jazz. Maybe I’ll pick one up somewhere. Thanks for the suggestion.
Kathy from Cold Climate Gardening
I have only seen crepemyrtles when visiting the South. To me they are very beautiful and I never understood “crepe murder.” Now I understand there was some misinformation involved.
Kathy, that was funny! Thanks for sharing and giving me a laugh the day after Hurricane Isaac hit us! We survived the hurricane with some minor damage to the property. All my plants look terrible but hopefully will straighten out in time. We have a lot of work ahead of us.
Donald, I’m glad the damage wasn’t too terrible. Yes Kathy, “crape murder” was a term coined to discuss overpruning. 🙂
Good info. I’ve seen only a few around here, planted no doubt by transplanted southern gardeners who yearn to grow them. Our winters can kill them off, as I’ve experienced when I tried to grow one. But I’m tempted to try again.
Carol, if the world gets any warmer, die off may not be a problem. Ha!
Lisa at Greenbow
I love crepemyrtles. I have only one. It was given to me by a friend who had a little sprout come up in her flower bed. It is pink. I am hoping her red one will some day throw off a sport someplace and I will then have a red one. 🙂 Interesting about the good DR going after reading that it couldn’t be done. We all like a little challenge.
I’m really glad you have one crapemyrtle, and it’s hardy at your place. When I interviewed Dr. Whitcomb, I loved that part of the story too. He’s done that with many different plants including a lacebark elm his company is named after. The study of plant genetics is so interesting.
I love the Dynamite Crepemyrtle. I have a triangular flowerbed with a Dynamite at each angle. The red flower is a showstopper! Along with the other plants in this flower bed, it is my favorite bed of the yard. I live in South Louisiana and the Dynamite is thriving.
Donald, I love it too. It is very free flowering and seems to have a lot of nectar for small pollinators. It’s also the truest red I’ve ever seen. Thanks for stopping by.