By outside, we mean outside the drip line of the plant, not near the base. I'd go out a foot or more from the drip line, then do a second cutting just outside the drip line. Gives you a longer time before the tree roots come back.

dig it up.. and find out whats going on.. underground ... if you cant see a problem ... there is only one answer ....

i will bet.. you will find 40% hosta roots ... and 60% tree roots ... most likely.. you will no longer be stumped as to the problem ....

i would move it elsewhere ..... in the 3 to 5 years it takes for the plant to recover to size.. the tree will also be recovering ... and you will be right back where you are ...

ive done what chazy says .. six of this.. half dozen of the other ... but my way ... you will see the issue ... then you learned something.. and can do other his way ....

ken

Trouble is Ken, it’s a big hosta. I don’t have another spot for it and it looked so good there!

If you start the slicing on the side closest to the tree, you will be able to tell if there is a lot of root competition--you can feel the roots being sliced through. If you don't get any resistance, then tree roots probably aren't the issue.

Thank you dhaven. I would never have thought of that. I’ll go and try that right now.

Okay. I used my transplanting shovel. The blade is 11 inches long. I can’t say I noticed any resistance when I stepped on it. It penetrated the soil almost the entire depth. At that depth though, I could feel the shovel hitting rocks. The soil is wet gumbo right now. I had a hard time extracting the blade. On the tree side I didn’t feel any roots. On the other side I could hear a few snapping sounds that I assumed were roots from a Russian cypress. But they didn’t offer any resistance. I sliced through them easily. Other hostas are growing around the perimeter of the cypress with no problem. But I would happily get rid of it if it is the issue.

I guess what I discovered is that the depth of the soil is 10 inches before hitting a base of rocky soil. Should that be a problem?

10 inches of good soil over a rocky base shouldn't be an issue. But you will want to trim the Russian Cypress roots back. Possibly way back.

Trouble is Ken, it’s a big hosta.

==>>> no big deal.. ive done it by just cutting the roots ... and then 'popping' it out ... and letting it fall right back down ....

and the only trick here is ... wait for it .... SHARPEN YOUR SHOVEL ... trust me.. it will make a big difference ....

then all that is left.. is wondering how all the rotting roots will affect the roots ... but i dont recall it ever being an issue ....

just do something... your choice.. i have no real vested interest in your choice ...

ken