Lawn Disease – Powdery Mildew

(Erysiphe graminis)

Powdery Mildew – is a common problem in shaded lawns and landscaping areas. In the United States, this turfgrass disease primarily affects lawns in the northern states from April through October.      

Identifying Powdery Mildew -

Powdery Mildew first appears as a felt-like, white mycelium on the surface of turfgrass leaves. The felt-like tufts enlarge and combine, causing the turf to have a grayish-white or powdery appearance. Severely infected turf turns yellow, tan and eventually brown in color. Infected turf in shaded areas can become thinned and eventually die.

Unlike other lawn diseases, Powdery Mildew does not require a film of water to infect turf. Generally this turfgrass disease is not severe enough to cause significant turf problems, except in shady areas.

Conditions for Powdery Mildew Infection -

Powdery Mildew can only lead to an infection in your lawn if all of the following conditions are present:

1. Pathogen – Powdery Mildew (Erysiphe graminis)

2. Host – Bentgrass, bermudagrass, fine fescue, Kentucky bluegrass or ryegrass

3. Environment – Humid, cloudy climates with temperatures ranging from 60-72 degrees Fahrenheit and turf areas with low light and poor air circulation

Powdery Mildew Control -

Cultural disease control practices create favorable conditions for a healthy lawn, and often create unfavorable conditions for the growth of Powdery Mildew. Environmental conditions cannot be changed, but cultural practices performed by the homeowner can be modified to lessen the chance of extensive damage from Powdery Mildew. Scotts LawnService can help determine a plan for preventing and controlling Powdery Mildew in your lawn.

For Powdery Mildew control and treatment, Scotts LawnService recommends the following cultural control tips:

  • Water 1 to 1 ½ inches per week to avoid drought stress
  • Infrequent deep watering is recommended verses frequent shallow watering
  • Avoid excessive amounts of nitrogen-based fertilizers to reduce lush leaf growth
  • Raise the lawn mowing height
  • Reduce the amount of shade  
  • Increase air circulation

Scotts LawnService has professional products that can prevent and control lawn diseases when cultural control practices are not effective.

Scotts LawnService is the trusted industry leader for professional quality lawn care. Our exclusive lawn care products include premium grass seeds and professional-grade fertilizers; our lawn service teams are comprised of highly trained, industry-certified professionals. Contact a representative today for Powdery Mildew control options available in your area and to learn how you can enjoy a lush, thicker lawn that only Scotts LawnService can deliver.