Brown spots on otherwise great lawn

Asked August 2, 2019, 2:08 PM EDT

What is causing these brown spots on our lawn? They are becoming more numerous. We do not have a dog or a pet. I thought it may be grubs but we also spread for grubs and have a lawn care service. How far how deep should I dig to check for grubs. We have had several large ant hills in the similar areas. More than we have had in past years. What could be the cause of the ant hills and is the a correlation to the brown spots?

Washington County Minnesota brown spots in lawn lawn and turf

1 Response

I am tempted to say Dollar Spot but your photos don't show any cobweb type symptoms. However, they only are apparent in the early morning if the grass is wet. It also could be Summer Patch. That is treated with fertilizer. Take a look at the suggestions in this link: http://apps.extension.umn.edu/garden/diagnose/plant/turf/circular.html