if your peonies are in a shady or dark spot they would rather grow leaves to gather little sunlight they have then use that energy up to prouduce flowers,if this is the case then replant!

Hi, how long have you had the plant in it's current position? if you plant them too deep they tend not to flower for a few years, the tubers should be just proud of the soil surface, as they like to get the cold in the winter, to flower well in spring, if you can't see the tubers, then they're planted too deep, dig them up and replant higher, keep well watered until they re-establish, and they will flower next year, even in partial shade, Derek.