DG, I'm not sure about those particular nut trees, but I'm sure you have heard of non-natives not doing well under black walnut trees (e.g. tomatoes). I understand that natives have evolved with the black walnut and have, therefore, adjusted to whatever the black walnut puts out into the soil. I wonder if it is the same with these particular nuts? On the other hand, your compost idea sounds pretty plausible too. I'm dying to hear what someone that really knows what they are talking about has to say. ;o)

Is it the ash or hickory that has the evil roots? Maple trees are notorious for doing that. Try searching under hostas and maple trees for how to deal with choking roots. Maple trees are more common so you should find lots of info on dealing with those. Hopefully the same would apply to your trees.

Walnut trees are fine to plant hostas under because hostas are not sensitive to juglone. Other nut trees do emit a little juglone but I don't think it's enough to be a problem.

Here is a link that might be useful: google

While the maples have certainly taken over the lower woods, to my knowledge there isn't a maple anywhere on the bluff zone where the yard is. I suspect the ash that stands about four feet from the front is the main source, and then there would be the shagbark hickories and white oaks. With the yard so full of trees I am sure it's nothing but a big twining mass of roots underneath it all.
It's bad enough around the hostas that if you had a very sharp knife or a good tile spade, you could actually cut out squares of ground which used to be soil and are now rootlets.

Experienced similar some time ago. Put in a small garden for my mother. 25 sq ft max. Put in good soil. Next to a fence which had a mature ash tree on the other side. On 1 side of the ash there was a young hickory, on the other a mullberry was growing. It was a 12" raised bed. Plants struggled and I found the same dense tree roots you described. I blamed the mullberry, but who knows? Live & learn.

My neighbor has hostas growing under a mature linden tree. The hostas look like they're doing fine.

Hmmmm.....haven't had that problem myself, but mine are under ash, maple, pine, tulip, chokecherries, and boxelder.
Be careful when you're diging up the soil around the base of a tree.......I realized for a few years after preparing the hosta beds and planting under the trees, that it hurt the roots, and the trees had problems for a couple years.
I don't quite understand why you're having such a root problem...... Sorry I can't help! Did you know there's a hosta forum here?

Scuse me while I smack myself in the forehead. A hosta forum. WHy didn't I think of that.....
And you are always telling me how s-m-a-r-t I am, too, Cathy!

I am guessing that maybe you either have to exclude the tree roots, or possibly up the water requirements or something.
The hosta hosts should know what I'm doing wrong.

Smack yourself all you want dirtgirl.......I still think you're smart!! :)
Don't forget there's also a tree forum here. You might want to post the same question on both sites. And don't smack yourself again, 'cause of the tree forum.

Would love to know what you find out. I have hostas and other plants under a maple. And yes, you can actually saw a chunk out of the "soil" which is really just roots. My hostas live, but stay the same size as when they were planted.

I have had some success with Pachysandra because it has such a shallow root system. Maybe you can look for plants with the shallow root system.

I would like to move some mature hostas and plant them under a mature sugar maple. As careful as I will be, would the maple be able to withstand some root damage