It doesn't seem late to me. I'm sure your ground isn't frozen. You'll be receiving bare roots I assume. Grafted maybe? These will be planted very deep and should establish a good root system over winter in the relatively warm deep soil, while the tops are nicely chilled ready to burst out in spring. This is ideal for Tree Peonies. So you now have 5 days to prepare your planting bed ;)

Whew. Thanks. Yes, bare root japanese and american from peonygarden.com

By very deep, do you mean the crowns should be below the surface?

Yes. Tree peonies, especially grafted ones, should be planted well below the surface. This is different from herbaceous peonies.

They won't have a crown as such because they will be a stick, probably without leaves, attached to the roots. Identify the graft point and make sure it is several inches below the surface of the soil. This helps to reduce suckers from the rootstock and may eventually cause the tree peony itself to produce its own roots.

thanks. GOt them today and they are indeed sticks.

GeeDavey
What cultivars of tree peonies did you get?

If the plants are grafted then as you go down the stem there will be an abrupt change in size. The herbaceous nurse root will be much larger. If grafted that union of tree peony stem and herbaceous nurse root necessarily has to be at least 2 inches below the soil line. I prefer 6 inches or more. Many time with small plants I only have one or two inches above soil. It may not sound natural for you to do this but believe me, it is worth it to you to try this.

Renown, Kamata Fuji and Kinshi.

Yes, they all look grafted, although the Renown does not have a very large herbaceous nurse root and has quite a bit more stem than the rest. They were promised to be 3yr + plants from peonygarden.com.

The Renown instructions say to "plant on a slant". I'll call them, but why would that be necessary?

It would be a good idea to get the graft at least 5" deep. also mulch them well. I always dig a cubic 2' hole and put in lots of goodies, remember this plant can outlive you! I dug one this fall that has been in the ground for over 20 years. I had to have help to lift it out of the ground. the rootstock was huge and the tree part had many roots. I have many tree peonies in my yard purchased at K-Mart over 35 years ago for $1.69. They came in a little box. I got the same little stubs from peonygarden.com last fall for $100. Times change.He said they were several years old but they were first year grafts.