It looks like your experiment with the leaf mulch is working. Here is my experiement with Fairy Ring.

While I was helping my sister in her garden recently I dug up a Krossa Regal that had the fairy ring. It was hard and dead looking in the middle so we removed the healthy outside part and planted it in several areas. The inside part reminded me of the old part of iris. There were roots attached and it wasn't mushy but I didn't really think it would grow. I planted some at her house and brought a piece home with me. I planted it with what I thought was the top up. Everything else has come up but that so I took it out of the pot to see what was going on. Below are the pictures. The eyes were trying to grow but from the sides and underneath. I replanted it "sideways". I'm not sure if the hard part which is above it will hamper it in some way? We'll see. McT

Something in your case is allowing the crown to produce new growth. Many including myself have cut fairy rings into pieces that ultimately grown in an approx round hosta mound.

I'm trying to get new growth in the interior and not move anything.

Two different ways of dealing with the condition, don't see one as better than the other.

And of course some don't mind the fairy rings they sort of look alright after they are fully leafed out.

Here is a later photo that hopefully shows the plant putting eyes in the center where there were none.

I reported that I didn't think it would fill the center but it has, if you can see that.

Hi Butch,
Have to taken off the leafs to see what's going on? I'm kinda curious to where the new growth is coming from. Is it actually the dead section of the crown, or just the opposite side of a outer crown? Luckily I don't have any plants with FR, but it'll be good to know if I ever do. Thanks!!

Hi Butch,
Have to taken off the leafs to see what's going on? I'm kinda curious to where the new growth is coming from. Is it actually the dead section of the crown"
hostasgalore

You are seeing it as I see it, I will continue to examine this clump more closely with photos and if I find my theory is wrong and evidence points to a different conclusion I'll post that.

One thing I want from this work is for others to replicate and report leading to a more conclusive answer.

At this point I am theorizing which leads to "old wives tales" so I'll just post photos and let time give the answers. One normally begins with an idea but the thought is not the proof. From my own words; "speaking to facts not in evidence"!

Sorry for the cheap camera, looking for something better.

This is a different plant developing a slight "fairy ring".

Notice if you can the eye at the lower right which exhibits eyes we have all seen that will not put an eye up in the center of the crown but will produce several eyes around the crown. This eye is only putting out an eye toward the outside of the ring.

Hopefully you can see the one I point out and in that same photo are other eyes that look the same but I don't think they will show up. In the second photo is the same feature but I don't think you can see it?

Now, this is what I observed on the Blue Angel. The outside edge producing eyes and inside not putting out eyes.

My theory is that nature takes care of itself. As the plant gets huge and the inner crown has no room to put off leaves and eyes, (and there are so many inner leaves that those inner crown/eyes/leaves are not receiving much sunlight and nutrition) the inner core starts to die off. It renews the plant by giving the outer ring the nutrition, sunlight , and room to grow. As the inner crown dies, it feeds the soil and the inner part of the outer ring now has room to put out new inner eyes, thereby refilling the center and starting the cycle again. I hope I explained that right! lol Long and short of it....leave them alone, unless you wanted to divide them anyway. With the additional room in the middle, they drape prettier, and you can't tell when they are leafed out anyway.

"My theory is that nature takes care of itself."
yardmom

Don't doubt what you say but want to understand the process then decide what I want to do from a knowledge base.

And I wondered if that shading out idea was the answer, if it were then additional organic matter would not change that reason. In this case the plant is making new eyes, is it chance?

This is the latest photo of this fairy ring trial on 04-25-08.

Remember this was the classic fairy ring when I started 2 years ago and now it is growing vigorously in the center again.

I think I can say that the mulch volcano works for the fairy ring.

In this latest photo you can see the rock that is quite large is now about to disappear.