Mary… Just curious do you want the blooms to open on the plants ? Or if you needs blooms for some reason you can cut them and put them in water with a touch of seven up or flower fresh in water to keep the water from spoiling. I like to force a few peony's to bloom ahead of the garden blooms.
To force the buds to open…Cut the flower stem first thing in the morning. Place them in water over nite in the garage to soak up water, bring them in the next morning add fresh cut then follow with the above directions for floral display. I usually can keep them in the fridge after blooming for a couple of weeks. Or keeping them in a cold room or window will also prolong the blooms.