I have these potted peonies which I got cheap, now at the end of the season. Should I transplant them to the garden as potted green plants? or should I let them go dormant, and then plant the dormant root in a few weeks?
The ground here will freeze in about a month.

As long as you get them in the ground before the ground freezes you should be fine either way; I'd do which ever is more convenient for you. I assume your weather has cooled enough so that they won't need a lot of babying if you plant them now?

Yes, it has cooled down so I don't think too much is growing.
Thanks for your quick reply.
I don't want to start them into growing, and then have them knocked down by a killing frost.
I did that last year with dormant fern peonies. They rotted before the frost came.

If they are already happy in a pot, you can keep them in a protected place in a garage as long as the temp is above a hard freeze. I kept some bare roots I had purchased from a garden center for 75 cents each in a refrigerator crisper tray over winter then planted them at the first warming of the soil. 11 out of 12 survived and the one which failed was the one I dug early to see if it was growing. Some vendors keep them in cold storage over winter and sell them in spring. I would not plant them if freezing soil is imminent even though the conventional wisdom is plant them any time the ground is not frozen. If you have several, split them into two groups and plant one but store the other. That way you can only be half wrong.

If they are established in the pot with green foliage I would plant now.

The roots should take the cold as long as they are not watered?
My garage is not heated. And I don't have a garden frig.
So I am thinking I should let them start towards dormancy, and then plant them.

I have three peonies coming any day. The ground is hard down a few inches in the morning but no problem digging the holes now. Besides they always seem to come right on the edge of late for us here. But they have always survived and done well. I used to dig the holes and store the dirt in the garage to assure I had a nice place for them. I don't bother now.

Just make sure your pots are protected from any freezing between now and when you plant them, Caroline. Peonies can take the freezing fine but don't do well with freeze/thaw/repeat!

I have them in the house for now.
I need to prepare a place for them in the garden beds.
(I am still clearing branches from that early snow fall.)

I found this info while checking USDA temperature zones. I saw where zone 3 can range as low as -40°F which is pretty harsh. That is why I mentioned a half and half solution. This link has nothing to do with temperatures but follows much advice about digging a large hole for peonies. Has to do with the root formation. http://www.ilovepeonies.com/Po...

Thanks Jerry, I enjoyed reading the article!

That is a good article.