Fungus on Crepe Myrtle: 5 Common Issues & How To Resolve

Many people appreciate having crepe myrtles in their landscapes for their colorful flowers and timeless appeal. Regrettably, these beautiful trees are prone to fungal infections.

If you’ve noticed something amiss with your crepe myrtle, you might be dealing with a fungal issue, but don’t despair!

With the right knowledge and tools, you can identify and treat these problems, restoring your crepe myrtle to its full glory.

How do you get rid of fungus on crepe myrtles? Getting rid of fungus on crepe myrtles involves a combination of cultural practices, proper sanitation, and the use of appropriate fungicides. It’s crucial to identify the specific type of fungus affecting your tree as different fungi require different treatments.

In the following, you’ll learn which fungal infections are common, environmental conditions that favor fungal infections, signs and impacts of fungal infection, and how to prevent fungus on crepe myrtles.

Key Takeaways

  • Common fungal diseases that affect crepe myrtles include powdery mildew, Cercospora leaf spot, sooty mold, crepe myrtle blight, and root rot
  • High humidity, poor air circulation, and improper watering can favor fungal infections.
  • Early detection is crucial. Look for discolored or spotted leaves, powdery or sooty substances, wilting flowers, or stunted growth.
  • Prevention involves proper watering, fertilizing, pruning, and choosing disease-resistant varieties.

For a detailed guide to common issues that affect crepe myrtles, be sure to check out my article, Crepe Myrtle Diseases and Pests.

Fungus on Crepe Myrtle – Identification & Treatment

Understanding the different types of fungal diseases that can affect crepe myrtles is the first step toward effective treatment.

Powdery Mildew

Powdery mildew is a common fungal disease that manifests as a white or gray powdery substance on the leaves, stems, and flowers of crepe myrtles. It can cause leaf curling, stunted growth, and reduced flowering.


Powdery mildew can often be controlled with regular applications of a suitable fungicide, such as neem oil or a sulfur-based product.

Increasing air circulation around the tree and avoiding overhead watering can also help prevent this disease.

Cercospora Leaf Spot

This disease is characterized by circular or irregular brown spots on the leaves. As the disease progresses, the leaves may yellow and fall off the tree prematurely.


Regular applications of a suitable fungicide can help control Cercospora leaf spot. Removing and disposing of infected leaves can also help prevent the spread of the disease.

Sooty Mold

Sooty mold is a black, powdery fungus that grows on the honeydew excreted by pests like aphids. While it doesn’t directly harm the tree, it can block sunlight and reduce photosynthesis.


Controlling the pests that produce honeydew can help prevent sooty mold. If the mold is already present, it can often be washed off with a strong stream of water or a mild soap solution.

A leaf coated with black sooty mold against a black background.

Crepe Myrtle Blight

Crepe myrtle blight is a fungal disease that causes wilting, browning, and eventual death of branch tips. The affected parts may also be covered with a gray, fuzzy mold.


Prune and dispose of affected parts promptly to prevent the spread of the disease. Regular applications of a suitable fungicide can also help control crepe myrtle blight.

Root Rot

Root rot is a serious disease that can cause wilting, yellowing leaves, and eventual death of the tree. It’s often caused by overwatering or poor drainage.


Improving soil drainage and avoiding overwatering can help prevent root rot.

If the disease is already present, you may need to remove and replace the affected soil and treat the tree with a fungicide specifically designed for root diseases.

Environmental Conditions Favoring Fungal Infections

Certain environmental conditions can make your crepe myrtle more susceptible to fungal diseases. These include high humidity, poor air circulation, and excessive or insufficient watering.

Overcrowded planting, lack of sunlight, and poor soil conditions can also contribute to fungal problems.

Understanding these conditions can help you create an environment that discourages fungal growth and promotes the health of your crepe myrtle.

Signs of Fungal Infection on Crepe Myrtle

Early detection of fungal infections is crucial for effective treatment.

Signs of fungal infection can vary depending on the specific disease but may include:

  • Discolored or spotted leaves
  • Powdery or sooty substances on the tree
  • Wilting flowers
  • Stunted growth
  • General decline in the tree’s health and vigor

Regularly inspect your crepe myrtle for these signs to catch any potential issues early.

Impacts of Fungal Infection on Crepe Myrtle

Fungal infections can have a range of impacts on your crepe myrtle. In addition to the visible symptoms, they can weaken the tree, making it more susceptible to other diseases and pests.

Severe or untreated infections can lead to significant damage or even death of the tree. However, with prompt detection and appropriate treatment, most fungal diseases can be effectively managed.

Preventing Fungus on Crepe Myrtle

Prevention is often the best defense against fungal diseases. This can involve cultural practices, such as proper watering, fertilizing, and pruning, as well as choosing disease-resistant varieties of crepe myrtles.

Regular monitoring, proper sanitation, and the use of fungicides as a preventative measure can also help keep your crepe myrtle healthy and free of fungus.

Best Fungicide for Crepe Myrtle

The best fungicide for your crepe myrtle will depend on the specific disease you’re dealing with.

Some recommended options include:

Always follow the manufacturer’s instructions when applying fungicides.

For even more recommendations and information on fungicides, check out: Best Fungicide for Crepe Myrtle.

Related Questions:

Should Crepe Myrtles Be Pruned?

Yes, crepe myrtles can benefit from regular pruning to maintain their shape, remove dead or diseased wood, and promote vigorous growth and abundant flowering.

However, avoid heavy pruning, also known as “crepe murder,” which can harm the tree.

Why Is My Crepe Myrtle Not Growing?

Several factors can affect the growth of crepe myrtles, including inadequate sunlight, poor soil conditions, improper watering, and diseases or pests.

If your crepe myrtle is not growing as expected, it’s worth investigating these factors.

Closing Thoughts

Fungal diseases can pose a challenge to crepe myrtle owners, but with the right knowledge and tools, you can identify, treat, and prevent these issues.

Remember that a healthy crepe myrtle is the best defense against fungal diseases, so invest time in proper care and maintenance.

Learn more about the pests and diseases Crepe Myrtle are susceptible to in these articles: