In general, a peony does not need additional, artificial support. Hybrid varieties with double blooms sometimes struggle and slump under the weight of their large blooms, but this is not dangerous or harmful to the plant. Peonies with single blooms and a few stronger-stemmed hybrids with double blooms can stand on their own with no support. If you prefer the look of your peony when it is standing tall and your peony struggles under the weight of heavy blooms, add an inconspicuous wire tomato cage to the base of the plant to help hold the weight of the blooms.
Cut the bottom ring from the tomato cage with wire cutters. A tomato cage has four vertical poles with a series of four horizontal circles that are progressively smaller as they move up the poles. When using the cage for tomatoes, the bottom circle rests on the ground and the "legs" of the cage extend into the air. Cut the vertical poles attached to the bottom circle where they meet the second ring, so that you have one ring with four legs. Discard this ring, or use it to stake a smaller peony.
Turn the tomato cage upside down and place the cage over the peony.
Press the legs into the ground until the first circle is a few inches from the ground.
Pull the stems of the peony through the supports allowing the stems to rest on the nearest wire circle.
Cut additional circles from the tomato cage to make a smaller support structure for shorter peony bushes.