Green Rings in Lawn
I had green rings show up in my lawn towards the end of last summer (2017). I did some research and I think it's a fungus of some sort. I wanted to get some advice on the best way to treat it. The photos attached are from a few weeks ago (March 4th). Any advice would be greatly appreciated!
This looks like a fairy ring. In most instances it is not a pathogen issue and no fungicides are recommended. Fairy rings form a tight area in the soil so moisture and nutrients cannot penetrate through. Take a look at our website for photos and more information. https://extension.umd.edu/hgic/fairy-rings-lawns
You can core aerate in the fall to break up the mycelium and overseed. Follow U of MD fertilizer recommendations. Best time to fertilize is in the fall.
See our website on seeding https://extension.umd.edu/hgic/plants/seedingsodding-lawns
Test your soil if not done within the last 3 years. Results give pH, liming, and fertilization recommendations. http://extension.umd.edu/hgic/soils/soil-testing