My favorite places to buy tree peonies are Solaris Farms and Klehms Songsparrow. It is better to have quality than quantity. It also allows you to look at the different types lutea, rockii and suffruticosa and see what you like. Both of those places grow their own and stand behind what they sell, also will be true to name and provide you will extremely detailed instructions for success.
Good luck and do let us know what you choose
