Powdery Mildew: What it is and how to get rid of it!
I’ve received numerous questions lately asking, “What is that powdery substance on my plants, and what can I do about it?” You may find it on Crape Myrtles, Indian hawthorns, roses, and many other landscape plants. That white or gray coating may be a fungal disease called Powdery Mildew.
Recognizing Powdery Mildew
Powdery mildew is one of the easier plant diseases to recognize. It usually appears as white or gray powdery patches on the leaves, stems, and sometimes buds of infected plants.
There are many different fungi that cause powdery mildew, but the symptoms they produce can look very similar.
What Causes It?
Powdery mildew fungi produce spores that can spread from plant to plant by wind. Conditions that include high humidity, moderate temperatures, poor air circulation, and crowded plantings can encourage the disease to develop.
Unlike many other fungal diseases, powdery mildew does not require constantly wet leaves to become a problem.
What Does Powdery Mildew Do?
Although unattractive, powdery mildew usually isn’t fatal to an otherwise healthy plant. However, a severe infection can stress the plant and interfere with healthy growth.
Infected leaves may become distorted, yellow or brown, and eventually drop prematurely. If flower buds are heavily infected, they may also fail to develop or open properly.
The Good News
Many of the fungi that cause powdery mildew are host-specific, meaning they infect particular plants or groups of closely related plants. The powdery mildew affecting one type of plant may not necessarily be the same species affecting another plant in your landscape.
Treating Powdery Mildew
If powdery mildew becomes a recurring or serious problem, a fungicide labeled for powdery mildew on your particular plant can be used as part of your treatment plan. Fungicides generally work best when applied preventatively or during the early stages of infection rather than after a plant is heavily affected.
Always read and follow the product label carefully to make sure the fungicide is appropriate for both the plant and disease you’re treating, and follow all application and reapplication instructions.
Help Prevent Powdery Mildew
• Choose resistant varieties when possible. Some plant varieties have better resistance to powdery mildew than others.
• Keep your landscape clean. Remove fallen leaves and old plant debris rather than allowing it to accumulate in your beds.
• Remove heavily infected plant material. Pruning affected leaves or stems can help reduce the amount of infected material on the plant. Clean your pruning tools afterward.
• Give your plants room to breathe. Proper spacing and pruning can improve air circulation around foliage and help create conditions that are less favorable for disease.
• Keep plants healthy. Proper sunlight, watering, drainage, and overall plant care can help plants better withstand disease problems.
Not sure whether that white coating on your plant is powdery mildew? Stop by The Home & Garden Center or bring us a few clear photos, and we’ll help you figure out what’s going on and find the right treatment for your plant!