Peonies are amazing perennials. Interesting how you even see them growing on abandoned farmsteads without any attention. Simple care of full sun and well drained soils is all you need.
Once the plants are done blooming, it is well worth your while to deadhead the old flower heads. You do not want the plants to produce seed so removing the spent blooms it does not allow the plants to waste its food making seed, but storing food instead.
The other thing deadheading does is prevent fungal disease from affecting the plants.
Lastly, removing the old flower heads really cleans up the plants appearance and make them a nice green plant in the perennial or shrub border for the balance of the season.
Keep your Peony plants looking good, continue making food, and prevent disease simply by cutting off the old flowers with a sharp knife or pruners. If you haven’t done so, it is not too late.
Peonies are best dug or divided in the fall if you are planning on moving any. Wait until fall to do so.
After deadheading looks great and is best for the health and vigor of the plant.