I think I posted here last spring about an experiment with an old plant developing the "fairy ring".

I piled ground up leaves like a volcano in the middle of the fairy ring covering the entire plant out to the edges. I did not remove the heavy application of mulch in the spring. NOTE: do not use unground leaves as a thick mulch.

This year it grew with new eyes on the inside edge of the ring. They did not just jump out of the center of the ring rather on the inside edge where eyes had stopped.

The inside edge becomes woody which doesn't allow new eyes, (I think) and the heavy mulch decomposes these old woody eyes allowing new ones to push through.

I stand by my fieldwork but not the theory, which is speculation.

Hopefully others will try this bringing more data to the experiment, we may now know how to affect the problem. This winter is time to do it if you care to try it.