Q. We visited almost exactly a year ago (mid may) and the most beautiful tree peonys were blooming. Do you know anywhere that sells these? One
Cricket Hill Gardens is a well respected peony nursery in Connecticut. They have a lovely selection of tree peonies as well as herbaceous peonies and great advice on successful cultivation. They do not carry the Shimane Otoni Mai (Young Dancing Girl) peony that you loved, but have a large selection. Klehm's Song Sparrow is another fine nursery based in Wisconsin that does carry the peony you are interested in.
Courtesy of NYBG Plant Information Service