We are told to plant peonies in the fall, but nothing happens above ground until spring? Do the roots continue to grow
in winter? If so what is the energy for this?
Stored in root? Or is the fall planting just so they have been
vernalized?
Is there a chart somewhere which would tell what peony roots are doing throughout the year? There are charts for bulbs which show the growth stages,but I have not come across one for peonies?

Good question! I think they're completely dormant in the winter so don't do much of anything. I think the only reason fall planting is deemed better than spring planting is that dividing the roots is pretty traumatic and dividing when they're going dormant is safer than dividing when they're starting to grow for the year. Transplanting 3-5 eye divisions in the spring is no more risky in my experience than in the fall; they just typically won't bloom that year. I've ordered from Gilbert Wild and Hollingsworth for spring delivery before and those peonies did just as well as fall planted ones.

Somewhere I read that they form the buds which become shoots.
In winter. But I imagine it depends on how cold winter is for them.
I would like to see a temperature chart for what peonies do over the winter.
I don't want to dig a bunch up to see for myself.
But maybe one year I could plant one in some kind of translucent container, and bury it in fall
under mulch. Then I could dig it up and re bury the container over the winter.

I accidenetally unearthed one I had planted a few weeks ago . the eyes had swelled and had grown a few 2 inch long feeder roots. the temperature has been consistently warm.

Thanks for the observations.
to the ATP peony forum.

I have read that peonies begin to develop feeder roots in the fall and even in winter as long as temps are above 40 degrees. By spring they are ready to send up new growths so the peonies stop developing feeder roots. If you plant peony roots in spring, you will find that the tubers do not develop feeder roots during spring and summer. The growths that occur seem to draw its food from the tubers instead. That is why spring planted peony takes longer to become established.

Thanks for that explanation.
Roots, that I will put in soon, won't get much grow time before the hard freeze.
The soil temperature is around 8º C or about 45ºF right now.

That explanation adds to the advice given by most peony vendors concerning replanting too many eyes in relation to the size of the storage roots. All the nutrients and growing power for the next Spring are in the current roots. I can see why a peony can bloom the first Spring but not the second Spring. Another thing to remember is usually the under the ground temp will be several degrees warmer than the surface temp.

Yes the ground temperature stays warmer, but when it is very cold in the air:----
it will go below freezing where the peony roots are.
A layer of mulch will keep them warm for longer.
Usually mulch after the ground freezes, but this is one time where mulch to keep
the roots warm might be effective?

I've noticed that the pips on my newly planted peonies seem to increase during the winter. Because we live further south, it takes a much longer time for our soil to freeze, and it doesn't stay frozen for long.

Several years ago, one of my newly planted tubers put up a stem during the middle of winter, which of course didn't make it, but the plant was fine, and grew normally with new stems the following spring once it warmed up.

That is reassuring! that a shoot might be damaged ,but not the whole plant.

That is reassuring, Annette! Two of my newly planted roots put up a stem this fall. I was hoping they'd make it though, nice to hear someone else has had that happen.

A year or so ago all of my peonies had nice red pips showing as we headed into winter. Many other growers reported the same thing. None were hurt and all bloomed the following year. I have four roots with 6" stems that I stuck in a pot last fall. All four had pips which is what prompted me to do so. They have gotten a bit larger over winter in the dark crawl space which has held at 55 and now down to 50 (weather has finally gotten cooler - in the teens and low 20's) as the outside temp affects the crawl space temp despite insulation around the edges and closing up the vents. I store dahlia tubers down there and last year one pot of lilies which insist on growing. drat.

The peony roots and shoots must start, and stop,
growing through the winter depending on soil temperatures?

No clue. The ones (pips) in the basement haven't changed much but I haven't unpotted them to check out the roots. I only understand about the different roots from comments here. Guess I will see in spring when they go into the ground. They didn't have much in any kind of root and actually no tuber to speak of. Mostly just a stem with a pip which is why I didn't want to just toss them. They were growing and deserved a chance.

Plants are amazing aren't they?

they are among the toughest that I grow here. Little bothers them except my stupidity sometimes.