Crepe myrtle bark peeling

paperbark maple, Acer griseum

Scientific Name

Acer is Latin for “sharp” and may also be from the Celtic ac, which means “hard” in reference to the wood; griseum means “gray” which refers to the underside of the leaf.

Common Name

Paperbark maple is named for its paper-like, peeling bark. Other names include Chinese paperbark maple.

NATIVE RANGE AND HABITAT

Paperbark maple is native to central China. Trees grow in moist, sheltered sites. It was introduced into cultivation by Veitch in 1901.

CONSERVATION INFORMATION

Not native to Kentucky.

DESCRIPTION

Growth Habit and Form

Paperbark maple is a small, deciduous tree with a neat, compact shape. Trees typically grow 20 to 30 feet in height with a spread equal to height. The trunk is short and the canopy oval or rounded.

Leaves

The blunt, toothed leaves are opposite and trifoliate (comprised of three leaflets). Leaflets are dark green above with paler hairy undersides. Paperbark maple displays excellent fall color. Leaves turn an array of bright red and orange colors in the fall.

Flowers

Flowers are green, small and inconspicuous; they bloom in spring.

Fruit

Fruit is a pair of winged seeds called samaras. Each samara is less than 2 in. long. The fruits ripen in the fall and are scattered by wind.

Bark

The bark is brown to reddish brown and peels away to reveal new rich, cinnamon colored bark. Exquisite bark character develops early as second year wood usually exfoliates. The bark of this tree is one of the most decorative barks of any maple tree.

Wild and Cultivated Varieties

Unlike many other species of maple, the paperbark maple has no wild or cultivated varieties.

HORTICULTURE

Landscape Use

Paperbark maple is one of the most beautiful and recognizable of all the maples. It is an outstanding ornamental tree. Trees make a wonderful specimen.

Hardiness Zone

Hardy in USDA Zones 5 to 7.

Growth Rate

Growth rate is slow, 6 to 12 inches per year over a 10 to 15 year period.

Cultivation and Propagation Information

Trees do best in moist, well-drained soils, both acid and alkaline. Trees perform well in clay soils. Paperbark maple grows best in full sun although tolerates partial shade. Balled and burlapped and container grown trees can be transplanted in spring. Paperbark maple may be propagated by seed, but the rate of seed viability is usually very low.

Diseases and Insects

None serious

Wildlife Considerations

Maple trees provide homes, shelter and food for wildlife.

Maintenance Practices

Minimal attention given appropriate cultural conditions.

TRADITIONAL AND MODERN USES

Paperbark tree is a native of China but has become an ornamental favorite in North America and Europe.

Crepe Myrtle Town House – Knowledgebase Question

White Tower Crape Myrtle does have cinnamon colored blotches on its trunk, but the flowers are somewhat disappointing. However there are several new hybrids with bark that is really something special in the winter landscape.
This hybridization primarily is between Lagerstroemia indica, the old-fashioned crape myrtle of our ancestors, and Lagerstroemia fauriei. Both are native to China, Southeast Asia and Japan.
Most of the crape myrtles with this eye-catching, exfoliating, mottled bark came out of the U.S. Department of Agriculture’s breeding program that began in 1962. Researchers were crossing plants looking for better blooms and disease resistance. These varieties are named after Native American Indian tribes.
Some of my favorites from the standpoint of bark are Apalachee, Biloxi, Comanche, Miami, Natchez, Osage and Wichita.
Apalachee is a small variety, reaching 12 feet in height and producing 9-inch-long panicles of lavender blossoms that are gorgeous. The Apalachee’s bark may best be described as cinnamon to chestnut-brown.
Biloxi is a pale pink, flowered selection prized by many home landscapers. It is a tall variety reaching 20 feet in height. The exfoliating bark reveals a dark brown color underneath.
Comanche produces coral pink flowers and reaches close to 12 feet in height. I grew this one in Mount Olive and loved its long bloom season. The exfoliating bark on this one is not as dark but still a pretty sandalwood color.
Miami is a taller variety reaching 16 feet by year 12. It produces dark pink blossoms and dark chestnut-brown inner bark.
Natchez is a 21-foot-tall white blooming selection and a Mississippi Medallion award winner. The deep cinnamon brown bark develops around the fifth year.
Osage is a light pink selection than can be grown as a large shrub or small tree reaching 12 feet in height. As the bark sheds, it reveals a mottled chestnut-brown look.
Wichita is a picturesque light magenta variety reaching 16 feet in height. This bark is truly exceptional with a dark brown to mahogany color.
There is another attribute many overlook. These varieties are also known to have some of the best leaf coloration in the fall as the green gives way to burgundy, orange, red and yellow.
Visit Monrovia’s website for even more choices. Just look for selections named for Native American Indian tribes and you’re sure to find one you like.

Crepe Myrtle Bark Scale is a relatively new nonnative scale that was first detected in the U.S. in 2004. Slowly over the last 13 years it has moved northward and is now a serious threat to Crepe Myrtles in Hampton Roads.

Crepe Myrtle Bark Scale (or CMBS) is relatively easy to identify in heavy infestations, but can be difficult to notice in its early stages on Crepe Myrtles. CMBS has only infested Crepe Myrtles in the U.S. so far, but in other parts of the world it has infested other species of plants that we do plant in our area. This is why it is so important to identify and control this insect now before it begins to spread to other plant species in the future.

Heavily infested crepe myrtles will have large almost completely encrusted sections of the bark or twigs covered in white scale. CMBS produce large quantities of honeydew, a sticky substance that gets on the leaves and branches and trunks of the plant and then will usually encourage the development of sooty mold, which will turn dark brown to black over a short amount of time. Smaller infestations are much more difficult to identify, in the nymph stage they are very small and usually pink, gray or brown. The adults create a white covering making them easier to spot. CMBS will mainly eat off the twigs, branches and trunks. Most infestations begin in the smaller branches and twigs at the top of the tree, making larger specimens harder to initially identify until the bark scale moves lower down the tree. One adult can lay up to 300 eggs, making this scale one of the fastest to spread in short time frame.

Treatment of Crepe Myrtle Bark Scale has to be done in stages and the time of the year will dictate what you should treat with. The late fall to early spring time frame is an easier time to identify whether or not you have a problem, as there are no leaves and blooms to hide the infestations.

Treat in late fall to early spring with a high quality oil spray like Fertilome Horticultural Oil Spray. With 80% mineral oil this product works as a suffocant and will kill the scale and the sooty mold. The mold and the scale both need to be coated in the Horticultural Oil in order to be controlled effectively, so spray the branches, twigs and trunks liberally until dripping. Spray nearby Crepe Myrtles as well, as newly or slightly infested plants may be unnoticeable. Repeat applications every 2-3 weeks or as needed, and always read label and instructions before using any control.

The Crepe Myrtle Bark Scale that dies will discolor and fall off the tree over time. The sooty mold will eventually wash off naturally, but can be washed off gently with soap and water on the main trunks and branches where applicable and noticeable.

Treatments will need to be made in the late spring to early fall time to completely control the Crepe Myrtle Bark Scale. In a future blog we will discuss the importance of treating CMBS with Systemic Insecticides which are much stronger during the growing season to really control the scale, and other effective fungicides to control the sooty mold as well. These products listed below will be discussed in detail then:
•Fertilome Systemic Insect Drench
•Hi Yield Systemic Insect Spray
•Fertilome Broad Spectrum Fungicide
•Fertilome F-Stop Fungicide

Crepe Myrtle Bark Scale is a serious insect issue to one of our beloved trees in Hampton Roads and with proper identification and control methods together we can control this issue. Please stay tuned to our blogs for future information and control methods for the Crepe Myrtle Bark Scale. Please visit any of our year round locations to talk with a Garden Pharmacy employee to help identify and control any issues you may be having in your garden or landscape.

The crape myrtle bark scale, an invasive insect species from Asia, secrete a sugary solution, known as honeydew, that subsequently results in black mold along the branches and tree trunk, Vafaie said. The crape myrtle bark scale has not shown to be fatal for plants.

But the bark scale do affect the aesthetics for the very popular ornamental tree, especially in the Southern U.S., Vafaie said. Observations suggest the crape myrtle bark scale could be responsible for stunted growth in plants as well as reduced flowering.

Two years of data collected by Vafaie and his collaborators show bark scale crawler, or nymph, numbers peak between mid-April and the beginning of May. He suggests two treatment options – contact spray or systemic – for landscapers or residents who have identified signs of crape myrtle bark scale based on data.

Trees can be treated with a contact insecticide spray as pest numbers peak, followed by another treatment two weeks later, he said. Insecticides with the active ingredient Bifenthrin have proved to work best during the study.

“Separate treatments in two-week intervals are good because you want to target bark scale in their immature stage,” he said. “You hit them during the peak and then two weeks later to catch those that have emerged following the first treatment.”

Vafaie said systemic treatments should be applied much earlier to allow the trees to uptake the insecticide for effectiveness. The best time to apply systemic pesticides is mid-March to the end of March, after leaves begin to bud out and trees are actively taking up nutrients from the ground.

“You want to have a systemic like imidacloprid or dinotefuran that will be taken up into the plant so that by mid-April to the beginning of May it will be present higher in the tree when the bark scale are feeding,” he said. “That way it will target them and kill them.”

Vafaie said the data collection has netted positive results so far and more research on crape myrtle bark scale is expected to follow in order to give ornamental growers, wholesalers and the public improved strategies against them.

“We’re collecting data this year and will in subsequent years to try and better understand how different temperatures during those years affect bark scale numbers,” he said.

Q: My crape myrtles have a fungus on them that is turning them black as well as the plants under the crepe myrtles. I’ve tried to use some Daconil that I have had in my garage, but this black scum doesn’t seem to be going away. I love to read your column and hope you can help me out with this problem.

A: I’m glad you enjoy reading the Horticulture Hotline and hopefully I can help you get your crepe myrtle to be clean and green again.

The black you are seeing on the crepe myrtle is a mold that grows on a sugary substance that aphids (in this case) excrete. Scale, white flies, lace bugs, mealy bugs and other insects excrete this sugary substance called “honey dew.”

Aphids are more of a pest problem to crepe myrtles than other insects. If you have a gardenia, it is probably white flies rather than aphids turning your gardenia black.

This black scum is often called “sooty mold.” The reason your Daconil didn’t work is because Daconil is a fungicide and your problem is an insect’s poop. An aphid has a very short digestive tract. Whatever goes in through the piercing, sucking mouth part, immediately exits the other end.

The plant’s juices that the aphids are feeding on is very sugary and makes a good substrate for the mold to live, therefore to control the mold, you must control the insect.

There are many insecticides on the market that will control aphids. There are organic soaps and oils, and there are contact and systemic control products.

The product I like to use for this problem is Dominion Tree and Shrub. Dominion is drenched at the base of the tree and the plant pulls it up into the foliage and protects the bush or tree from insect damage for up to one year.

Drenching is nice because you don’t have to spray the tree or shrub, avoiding any drift from the chemical onto you or another non-target plant. Dominion is also very friendly to beneficial insects since these insects are not sucking on the tree. The long-term control means less mixing and spraying of chemicals.

If any of your plants have a history of insect problems, now is a good time to apply Dominion for control.

Not only do these piercing, sucking insects take valuable nutrients away from the tree/shrub, but the black mold covers the leaves, blocking the sunlight and preventing the tree from manufacturing its own food.

Crape Myrtles are the most abused tree in the landscape. Since they bloom on new growth, someone “topped” them a while back and noticed the flush of new growth and the prolific blooms.

These heavy blooms are supported by wimpy 18 – 24 sprouts that just developed that growing season. When it rains, the bloom catches water and becomes even heavier. The bloom will hang down and eventually the wimpy new growth supporting the bloom will split off the tree, leaving an open wound for insects and disease.

Instead of “topping” the tree to increase blooms, a good fertility program will accomplish the same thing without ruining the beautiful natural branch structure of the tree. A soil test and program can guide you to the right fertilizer for your tree.

Bill Lamson-Scribner can be reached during the week at Possum’s Landscape and Pest Control Supply. Possum’s has three locations: 481 Longpoint Road in Mount Pleasant (843-971-9601), 3325 Business Circle in North Charleston (843-760-2600) or 606 Dupont Road in Charleston (843-766-1511). Bring your questions to a Possum’s location or visit us at www.possumsupply.com. You can also call in your questions to “The Garden Clinic,” Saturdays from noon to 1 p.m. on 1250 WTMA (The Big Talker). The Horticulture Hotline is available 24/7 at www.possumsupply.com.

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