Curb appeal matters. When people drive by your home, you want your lawn to look its best. Unfortunately, lawn diseases like powdery mildew on plants can make your lawn look dull while weakening its condition over time. This common fungal condition doesn’t kill your grass outright, but it impacts its overall vigor. With expert guidance, you can identify, treat and prevent powdery mildew and maintain your turf’s beauty.

What Is Powdery Mildew?

Powdery mildew affects numerous grasses, leaving a distinct white or grayish powder-like coating on leaves, stems and blades. Unlike fungal infections that thrive in overly wet conditions, this lawn disease prefers dry climates with high humidity. The condition weakens your lawn by interfering with photosynthesis — the process plants use to convert sunlight into energy. When you leave powdery mildew untreated, it can slow growth, yellow leaves and make grass susceptible to other diseases and environmental stressors.

How to Identify Powdery Mildew

Knowing the early signs of powdery mildew helps you spot it early and manage the fungal infection:

• White or gray powdery coating: This fungus most often appears as a dust-like covering on grass blades and resembles flour or baby powder.
• Yellowing or browning grass blades: Over time, areas affected by powdery mildew often turn yellow or brown as the disease takes its toll on healthy plants and grass.
• Slow or stunted growth: Powdery mildew on grass slows growth compared to surrounding grass, leaving portions of your lawn stunted and patchy.
• Vulnerable shaded areas: Powdery mildew thrives in shaded locations with poor air circulation, so watch areas under shrubs and trees for signs of the disease.

Homeowners sometimes confuse powdery mildew with other lawn conditions, including drought stress and nutrient deficiencies. Other fungal conditions sometimes resemble this disease, including dollar spot and gray leaf spot. However, unlike these issues, powdery mildew has a distinctive powder-like appearance that easily wipes off plants when touched.

What Causes Powdery Mildew in Grass?

Specific environmental conditions cause powdery mildew to develop. Consider these contributing factors to its growth and spread when you want to know how to treat powdery mildew on your lawn.

• Shaded areas: Grass growing under dense tree cover or next to sun-blocking buildings is more susceptible to powdery mildew.
• Poor airflow: Lawns with thick vegetation or areas of restricted airflow offer the ideal environment for powdery mildew to grow.
• High humidity: Humid conditions with warm daytime temperatures and cool nights cause powdery mildew to thrive.
• Lack of nutrients: Lawns with essential nutrient deficiencies — especially a lack of nitrogen — are prone to developing fungal diseases.
• Dense turf: Thick grass with poor airflow through the turf often attracts fungal spores.

Most Common Plants or Grass Types Impacted

In addition to grasses, powdery mildew attacks many ornamental plants, including zinnias, lilacs and roses, so watch for symptoms. Certain varieties of grasses have higher risks of getting this fungal infection, including:

• Kentucky bluegrass: A favorite ground cover for Midwestern and Northeastern lawns, Kentucky bluegrass is vulnerable to powdery mildew when planted on shady lawns.
• Fescue grasses: Popular in cooler climates and transition zones, fine fescue grasses often develop powdery mildew in shady and overly moist areas.
• Bentgrass: This finely textured grass thrives in cool-season regions, including the Northeast, Midwest and Pacific Northwest, but it’s vulnerable to powdery mildew in conditions with poor air circulation.
• Perennial ryegrass: Commonly sown in Northern states and coastal regions, this grass often falls victim to powdery mildew in cooler settings with higher humidity levels.

How to Get Rid of Powdery Mildew

Once you spot powdery mildew on plants and grass, swift action helps mitigate the spread of this fungal lawn disease. Use these methods to tackle the problem when you need advice on how to treat powdery mildew or what kills powdery mildew instantly.

• Improve airflow by trimming back trees and shrubs to let sunlight shine and increase air circulation.
• Keep grass at an appropriate height between 2.5 and 3 inches to promote strong growth and prevent excess shading.
• Reduce watering in shady areas because overwatering can create a damp setting that lets fungal spores spread easily across your lawn.
• Apply a fungicide labeled to handle powdery mildew in severe cases.
• Fertilize in a balanced way to keep your grass healthy and resistant to fungal diseases.
• Reseed your lawn with mildew-resistant grass varieties if your yard has recurring problems with powdery mildew.

How to Prevent Powdery Mildew

Follow these best practices to keep your lawn healthy and free of this fungal disease:

• Choose the right grass type. Opt for shade-tolerant grass varieties instead of Kentucky bluegrass or bentgrass for shady lawns.
• Aerate your lawn regularly to improve airflow and reduce soil compaction. This task makes it harder for powdery mildew to take hold.
• Keep up with lawn maintenance. Regular mowing, dethatching and proper fertilization help maintain a strong, disease-resistant yard.
• Manage shady areas strategically by pruning trees and shrubs to let light shine. Consider installing shade-friendly ground cover in areas where grass struggles to grow.
• Be mindful of watering schedules. Avoid overwatering shady areas.

By understanding the causes, symptoms and options for treatment and prevention, you can keep your lawn looking lush, healthy and free of unsightly fungal diseases like powdery mildew. Need expert help with your yard? Contact Lawn Doctor today for professional lawn care solutions that protect your yard from lawn diseases like powdery mildew with customized treatment and prevention strategies.