Lawn Powdery Mildew Disease
One Of The Lawn Fungal Diseases Or A Coat of White Paint?
Powdery mildew, one of several fungal diseases that infects the blades
of grass, leaves a white powder-like patch on your lawn. It usually
occurs on cool-season grass, such as Kentucky bluegrass, which is most
susceptible, as well as Bermudagrass, and all the grass fescues.
What Does This Mildew, Erysiphe Graminis, Look Like?
The first signs of this mildew damage are light patches of dusty white
or light gray growth on the grass blades. The lowest leaves can get
This mildew fungus, technically known as
Erysiphe graminis, infects the surface of the grass blades, where it
develops a fine, fungal growth that looks like white powder or even a
dusting of lime or flour.
In areas that have been hit harder by the disease, it can actually look like it's been sprayed with a coat of white paint.
When Does This Paint Brush Of The Lawn Fungal Diseases Strike?
- Late spring and summer, and in fall
- When temperatures are 60F - 70F and humidity is high
- In areas of poor air circulation
- More severe in densely shaded areas
- Appears quite suddenly, usually on Kentucky Bluegrass
Lawn Powdery Mildew Control
Here are some practical management suggestions:
- Reduce shade and increase air circulation by pruning nearby shrubs and tress
- If grass is not growing well in shady areas, consider replacing with shade-tolerant ground covers
- Raise the mower cutting height
- Don't use high nitrogen fertilizers
- Water infrequently but deeply
Things To Know About This Lawn Disease
- It is most common when weather is cool, moist, and overcast.
- It spreads primarily by the wind, and can start infecting grass blades within 2 hours of landing.
- The disease causing agent survives in dead grass over winter months.
More Lawn Diseases