What Causes Sooty Mold
Sooty mold is caused by pest infestations of small sucking insects with piercing mouths, including aphids, whiteflies, mealybugs, and scale. The insects secrete a sweet, sticky substance called honeydew, which coats the leaves and stems, or branches of certain plants. The honeydew coating attracts fungal spores, which adhere to the honeydew. Once a few sooty mold fungal spores are present, the fungus quickly spreads and affects the whole plant, making it appear as if it is covered in grime and soot.
Identification And Symptoms Of Sooty Mold Fungus
Identifying sooty mold fungus is fairly easy. If you notice a dark gray to black sooty coating on the foliage and fruit of a plant, shrub, or tree, chances are, sooty mold fungus is the culprit. If you notice the presence of honeydew on the leaves, branches, and twigs of one of your plants, you may have time to keep the fungus from forming. If you notice the presence of aphids, mealy bugs, or other tiny insects on your plant, you might even be able to prevent the spread of honeydew by treating the plant for pests before they have a chance to coat the leaves with their sugary-sweet substance.
The symptoms of sooty black mold are simple and easy to see. The affected plants become covered in a sooty layer of gray or black grime. The mold is powdery and sticky and the layer is relatively thick. The dark color and the thickness of the fungal growth blocks photosynthesis, which keeps the chlorophyll from functioning properly, which can eventually cause the leaves to wither and die. Though the leaves of affected plants are sometimes casualties of sooty mold fungus, the plants, shrubs, and trees live on long after the fungal growth has come and gone. Soot can be removed, leaves can be regrown, and plants that have been the victims of major infestations can make miraculous recoveries with proper treatment.
How To Control Crapemyrtle Bark Scale
This article covers the topic of controlling Crapemyrtle bark scale.
There is a fairly new, serious threat to one of our favorite trees. Its even more serious than the unsightly and oft mentioned crape murder. As a reminder, crape murder is the extreme pruning of crapemyrtles that results in weakened and deformed trees. If you arent sure how to properly prune your crapemyrtles, check out this post. Okay, jumping off that soapbox, lets talk about the Crapemyrtle Bark Scale. It has been around the Southeast for years but this insect showed its destructive little head in Arkansas in 2014. Are we gonna just take this or are we gonna fight? We say fight!
*Pictures of Crapemyrtle Bark Scale were provided by the University of Arkansas Cooperative Extension Service.
Crapemyrtle Bark Scale is a small insect that appears as a white or gray felt-like encrustation. CMBS might be found anywhere on crapemyrtles, and often appears near pruning sites and branch crotches of more mature wood. Often times, the first sign of CMBS is the black sooty mold on the tree bark. This may be misleading since a more common and easy to control pest, aphids, can also cause sooty mold. Closely examine the affected areas to properly identify the pest. Bring us samples or images if you arent sure.
This tree is heavily infested with CMBS notice the gray and white insects all over and the black sooty mold covering the entire surface of the tree bark.
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How Do You Treat Aphids On Crepe Myrtles
Crapemyrtle aphids feed by inserting slender mouthparts into leaves and sucking out sap that is rich in sugars. As they feed, aphids also inject saliva. This saliva causes pale yellow spots on the leaves. Since aphids consume large quantities of plant sap, they excrete sweet, sticky liquid called honeydew.
Sooty Mold On Crape Myrtle Trees
Crape myrtle trees are large shrubs or trees that are hardy in USDA hardiness zones 6 through 9 and flower in late summer, says the Missouri Botanical Garden. Aphids, scale insects, whiteflies and mealybugs commonly infest the trees and excrete the honeydew that feeds sooty mold fungi. Check for the pests on stems, stem tips, flower buds and the undersides of leaves. Aphids are tiny, soft-bodied insects that live in clusters scales look like small, flat, rounded shells whiteflies are tiny, white flies and mealybugs are small, white, segmented insects covered in a crumbly wax coating.
The sooty mold fungi can also grow on resin or sap that oozes from wounds in the stems or bark. If the black residue is coating only one area of your tree, check for a cut or gash, advises the University of California Integrated Pest Management Program. Sooty mold that has appeared due to a wound should stop growing when the wound heals.
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Black Sooty Mold On Crepe Myrtles Actually No Big Deal
The white insects are crape myrtle bark scale. Like other types of scale insects, they suck sap out of the plants leaves and stems and secrete a sticky honeydew that they exude all over the leaves and bark. A sooty mold fungus grows in it, and that fungus quickly develops a black color. It doesn’t really harm the plant, though.
Q: What is this on my crape myrtle , and what should I use to control both of them?
A: The white insects are crape myrtle bark scale. Theyre a relatively new pest in the United States, first being observed in Richardson in 2004.
Like other types of scale insects, they suck sap out of the plants leaves and stems and secrete a sticky honeydew that they exude all over the leaves and bark. A sooty mold fungus grows in it, and that fungus quickly develops a black color. The same sooty mold appears on old cars and pavement when trees drip sap on them.
The important thing to remember about bark scale and sooty mold is that they are mainly aesthetic. You can prevent them with a mid-May soil drench of Imidicloprid around the drip line of each crape myrtle. They actually do no permanent damage to the plant. Repeated topping of crape myrtles, such as I see in the photo, is far more harmful.
A freeze-damaged pyracantha seemed to recover and then lost some of the new growth. Neil Sperry recommends waiting until September to see how much additional die back there is and what needs to be done.
How Neem Oil Works
The neem oil disrupts the hormones of the insects preventingthem from molting and growing through their various stages. It also disruptstheir ability to lay eggs, therefore reproducing. I have also read that itmesses with their digestion, so they are sucking less on your plants.
Keep it mind it takes time, but only a few days depending onthe size of the infestation.
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How Do You Treat White Fungus On Crepe Myrtles
powdery mildewcrape myrtle
Diseases. Powdery Mildew: Powdery mildew is one of the most common problems of crape myrtle, and it is caused by the fungus Erysiphe lagerstroemia. Patches of white to grayish powdery growth occur on the surfaces of leaves, flowers and new shoots. Heavily infected flowers may fail to open.
Beside above, how do I get rid of powdery mildew? Combine one tablespoon baking soda and one-half teaspoon of liquid, non-detergent soap with one gallon of water, and spray the mixture liberally on the plants. Mouthwash. The mouthwash you may use on a daily basis for killing the germs in your mouth can also be effective at killing powdery mildew spores.
does powdery mildew kill crape myrtle?
They may even die. Flower buds covered with mildew fail to open. Powdery mildew won’t kill your crepe myrtle. It’ll just make it so ugly that you’ll wish it were dead.
How do you get rid of aphids on crepe myrtles?
Attract beneficials to help provide control. Spray the tree with a molasses solution and then release lady bugs . You also could treat with neem or a horticultural oil. Once the aphids are gone, the sooty mold will gradually disappear.
How To Treat Crepe Myrtle Bark Scale
Crepe myrtle bark scale treatment may require several different techniques, and management of the pest requires persistence.
Scrub the pests away It may sound odd, but scrubbing the tree will remove many of the pests, thus making other treatment more effective. Scrubbing will also improve the appearance of the tree, especially if the scale has attracted black sooty mold. Mix a light solution of liquid dish soap and water, then use a soft brush to scrub the affected areas as far as you can reach. Similarly, you may want to use a pressure washer, which will also remove loose bark that creates a handy hiding place for the pests.
Apply a soil drench Drench the soil between the trees drip line and the trunk, using a systemic insecticide such as Bayer Advanced Garden Tree and Shrub Insect Control, Bonide Annual Tree and Shrub Insect Control, or Greenlight Tree and Shrub Insect Control. This treatment works best between May and July however, it may take several weeks for the substance to make its way throughout the tree. A soil drench will also control aphids, Japanese beetles and other pests.
Spray the tree with a dormant oil Apply dormant oil generously, using enough oil to reach cracks and crevices in the bark. You can use dormant oil between the time the tree loses its leaves in fall and before new foliage emerges in spring. Application of dormant oil can safely be repeated while the tree is still dormant.
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Will Powdery Mildew Go Away
Air flow and ventilation will discourage mildew growth. Prune diseased plants to get rid of infected parts and increase airflow. When combating powdery mildew its best to think of it as treating allergies, something that will never go away, but having fewer symptoms each year by having regular treatments.
Honeydew Sets The Stage For Black Sooty Mold
In the case of the crepe myrtle aphid, that can be in the tree feeding on the leaves, but the excrements can be dropping onto a hibiscus under it.
As the crepe myrtle aphid is species-specific, the colony will not migrate to the hibiscus plant, but the hibiscus will still show the symptoms of an infestation.
Ant trails and the fungal growth of black sooty mold.
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Growers Ally Fungicide Concentrate
Growers Ally is undoubtedly the most eco-friendly item on my list. It is not only OMRI approved for organic use but also a FIFRA 25 exempted product. FIFRA 25 is a federal act & it declares that Growers Ally is safe for people & the environment. However, moving forward-
The chemical components are water, lactose, sodium acetate, sodium benzoate , potassium sorbate , ethyl lactate & Citric acid. Among these, Citric acid is the active ingredient. The remains boost up the action of Citric acid.
Now, Citric acid destroys fungi in several ways. Due to Citric acids low pH, the cell pH of fungi also gets lowered. Thus metabolic functions get suspended & cause death.
Another way is, Citric acid accumulates toxic ions that cause cell membrane disruption & death. And sometimes, fungi lose a lot of energy to balance the pH imbalance caused by the Citric acid & walk to death.
Mode of Action
Citric acid works as a contact fungicide. When it is applied, it comes into contact with the surface dwellers & kills them. Rather than getting absorbed, the chemical builds a shielding wall on the leaf surface that hinders fungus growth & spreading.
But, if the fungus is systemic & causes damages from inside, this item may not prevent it successfully. Thats why Growers Ally is trustworthy for preventive purposes.
The fungicide is a yellowish acidic liquid that aids in growing healthier cannabis and hemp. It is very effective against powdery mildew.
More On Crepe Myrtles
The crepe myrtles are among the most satisfactory of plants for the South: showy summer flowers, attractive bark, and brilliant fall color make them year-round garden performers. Long, cool autumns yield the best leaf display sudden frosts following warm, humid fall weather often freeze leaves while they’re still green, ruining the show.
Most crepe myrtles in gardens are selections of L. indica or hybrids of that species with L. fauriei. The latter species has attracted much notice for its hardiness and exceptionally showy bark. Queen’s crepe myrtle, L. speciosa, grows only in the Tropical South.
All crepe myrtles bloom on new wood and should be pruned in winter or early spring. On large shrubs and trees, remove basal suckers, twiggy growth, crossing branches, and branches growing toward the center of the plant. Also gradually remove side branches up to a height of 4-5 feet this exposes the handsome bark of the trunks. During the growing season, clip off spent flowers to promote a second, lighter bloom. Also prune dwarf forms periodically throughout the growing season, removing spent blossoms and thinning out small, twiggy growth.
Crepe myrtles are not usually browsed by deer.
Trained as a tree, it develops an attractive trunk and branch pattern. Smooth gray or light brown bark peels off to reveal smooth, pinkish inner bark winter trunk and branches seem polished.
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What Causes Black Sooty Mold On Crepe Myrtles
Insects activity causes black mold on crepe myrtles. Specifically, aphids are the primary cause here in Gainesville, although other insects can cause problems in other regions of the country. Aphids are sap-sucking creatures. As with any creature, they have to process what they eat. Thats the honeydew we mentioned a moment ago.
Black sooty mold spores float in the air and then stick to this honeydew. From there, as with any mold, it grows based on the appropriate conditions such as heat, humidity, and sun/shade levels.
Bonide Infuse Systemic Fungicide
Bonide has been working locally since 1926. Thenceforth, its premium quality products like Infuse Systemic Fungicide & user-friendly deals have made it truly admired & now Bonide has turned into an international brand since 2019.
Propiconazole is one of the most leading chemicals in the triazole fungicide group & this item contains 1.55% of it. DMI fungicide or DeMethylation Inhibiting fungicide is another name of Propiconazole & from this name, it is easy to figure out how it works.
The formation of Ergosterol is an extensive event for fungi cell growth & reproduction. If Ergosterol does not get incorporated into the cell membrane, it can kill the fungi by stopping cellular growth.
But before the formation of Ergosterol, there is an important step called demethylation & Ergosterol formation wont take place without this precursor step.
However, an enzyme called 14- alpha demethylase works as the demethylating agent. And guess what? Our active ingredient Propiconazole inhibits the enzyme from doing its job & thus affects fungal growth & reproduction.
Mode of Action
You already know about it. It is a systemic fungicide. It has both preventive & curative characters to protect your Crepe Myrtle for up to 4 weeks.
So, no matter what type of fungus attacks your crepe Myrtle, systemic or contact, Bonide Infuse can kill both types of pathogen.
Why for Crepe Myrtle
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Can Sooty Mold Kill Plants
Sooty mold covers plant tissue, often coating entire leaves with a dark grey to black soot-like mold. Though sooty mold infections are not typically lethal and appear to be a lot more severe than they are in reality, the mold layer does block the sun from the plants foliage, which decreases the photosynthesis processes within the plant and significantly weakens it. Though sooty mold fungal infections arent typically lethal, they are caused by sucking insects which can kill the plant if left untreated.
Treatment And Control Options For Sooty Mold Fungus
Prevention techniques for avoiding issues with sooty mold are hard to find because when the issue first starts to develop, it is not entirely recognizable. However, there are a couple of ways that gardeners can reduce the likelihood of sooty mold infections in the garden. One way to lower the chances of developing sooty mold problems is to raise healthy garden plants.
Healthy, happy plants are less likely to attract pests that produce honeydew. Keeping your plants properly hydrated and well fed can go a long way towards preventing sooty mold and many other pest and disease problems. If your plants become weakened by insufficient nutrients available in the soil, or by dehydration, they are more vulnerable to attack from pests and parasites.
Treatment & Control
Treating sooty mold fungus is relatively easy, as long as you are willing to follow the steps required to eliminate the cause of the fungus first, then remove the fungus from the plant entirely. Once the pest issue has been treated, the soot-like mold needs to be removed entirely. The removal process can take more than one treatment to get rid of all traces of the mold. Follow this easy step-by-step process that first focuses on ridding your plants of sucking insects which produce honeydew, and then on removing all traces of sooty mold from the plant.
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How To Fight Sooty Mold Fungus
If you have a plant, shrub, or tree that looks like it has spent a little bit too much time next to a fireplace, its leaves and branches covered with a thick layer of black soot like the face of a chimney sweeper after a double shift, theres a good chance that your plant is suffering from a fungal condition known as sooty mold fungus. Though the fungus does little actual harm to the plant it infects, it is certainly unsightly and an unwanted presence in any garden. Thankfully, it is relatively easy to treat and remove.