The blossoms don't last long, sometimes only 3 days - but their beauty certainly makes up for it. Tree peonies have woody stems unlike herbaceous peonies that have stems that die back to the ground every fall. Because the stems are woody - they don't need to be staked. Tree peonies will take some shade - and in fact, do a little better (and last a little longer) if they have shade in the afternoon. Cool temperatures also help extend the period of bloom. This 12C weather is just perfect - will take as many photos as I can, because it's going up to 32C this weekend and that will be the end of these pretty flowers.
Also note - that tree peonies can live for over a hundred years - so when you make your selection - buy the best you can afford - they will be around for a very long time!