What Kills Fungus on the Lawn?

Lawn fungus can be more of a nuisance than a danger.

You can keep your neighbor's dog off your lawn by building a fence, but a barrier will not stop fungus from ruining the appearance of your grass. Only fungicides and cultural controls can kill fungus on your lawn.

Lawn Fungus

Lawn fungus feeds on organic matter in your lawn. This can be decaying wood, leaves and organic matter in the soil or the grass of your lawn. Lawn fungi include mushrooms, dollar spots and powdery mildew. A lawn fungus can be an occasional nuisance or it can kill large swaths of your lawn.

Controls

In severe cases, fungicides can be used to kill lawn fungi. Most contain active ingredients like chlorothalonil, triadimefon and sulfur. Mushrooms are a fruiting body of a fungus growing within the soil. Aerating your lawn can eliminate the fungal mat, but in severe cases you could need new sod to eliminate it.

Considerations

Before using a fungicide to kill lawn fungi, try making culture changes that will gradually eliminate the problem. Reducing thatch, improving sun exposure and air circulation over the lawn and watering deeply and less frequently can make your lawn less hospitable to a lawn fungus.

References

• University of California IPM Online: Common Lawn Diseases
• University of Florida IFAS Extension: Homeowner's Guide to Fungicides