I check potted peonies, which I get on sale here at this time of year.
One year I found that the roots had been thrown in the pot,
and covered with soil, so the root was actually too deep,---- if I planted the contents at the same level.
Now I dump the pot out, and see where the root is located.
There are a couple of older peonies which are not doing well, and I think this may be the problem.
I need to dig them up, and check whether they are just below the soil surface.
Most potted plants are planted at the same level as they were in the pots.

Except for tree peonies. They should be planted deeper than they are in the pots so that 4 or so inches of the stems are below the surface.

Thanks----I did not find any tree peonies or Itohs on sale.
But I'll try to rember that tip!