Sometimes fairy rings develop in lawns especially in the spring during wet, cool weather.

There are three types of fairy rings:

type I: soil and thatch become hydrophobic and the grass dies; brown ring of dead grass

type II: rings on the lawn that are 2 – 8 inches wide with lush green grass

type III: mushrooms and puffballs are produced in the ring

white fungal mycelium can be found in thatch and soil for all three types

Control methods

Reduce thatch with proper cultural practices. https://extension.umn.edu/lawncare/how-control-thatch-your-lawn

Mask fairy ring; water deeply and fertilize to stimulate growth of grass around ring.

For type II fairy rings, a wetting agent may be needed.

Control with fungicide drenches is inconsistent.

Soil replacement: remove soil about 20 inches to each side of the ring and up to 30 inches deep and replace with sterile soil. This is a very expensive management option.

Aerate your soil in the fall to reduce soil compaction and improve drainage.

Please read pages 19 and 20.

https://www.ag.ndsu.edu/publications/lawns-gardens-trees/home-lawn-problems-and-solutions-for-north-dakota/h1553.pdf