Sometimes they can take three to four years to flower - have patience, it will flower!

Yes it can take few years to flower however what is your overall maintence and feed programe do you have. to much nitrogen can produce masses of leaves and very few flowers.

Check it out that the planting is shallow. Peonies like to be on the top of the soil. Try scraping some of the soil away round the base of the plant. No fresh compost on top as I once did, thinking I was doing it a favour.