I have often wondered if the reason most of mine climb to the surface is the bottom of the hole is too solid so it is easy to expand the root system vertically.

A couple of samples of my peony roots. These are part of a group planted in 2010.

Interesting, I've never noticed them surfacing like that before. Is your soil hard clay where it isn't amended?

This area is yellow clay under a layer of topsoil. The clay is mush when wet and nearly concrete when dry. I probably cheated on the size for the hole when planting and I plant them shallow.

This is my Early Scout in a raised bed. I have sprinkled a bit of organic material and sand over it during the past years to compensate for the organic material rotting and settling. It is almost like frost heaving.

How interesting. I plant shallow also and never had roots surface. I have lots of dead stems from prior years which I try to remove as they rot. I don't suppose they prevent the emergence of new pips. Peonies are the first of my 'larger' flowers to bloom and I just love to see them start around the middle of June. When I had some mature tree peonies they faithfully bloomed between June 20-June 23 like clockwork. I have some new ones but they have only been in the ground a year or so and no blooms yet. Several new herbaceous that I hope bloom this summer. I think I will put in a new bed in the front yard to add the four roots growing in a pot in the basement. Moose won't bother them as they are also herbaceous and they grow after the miserable meeses are gone back to the hills.