Fall is the best time to divide peonies. Sept/Oct actually, but I got to these this past week. It should be plenty of time for them to enjoy a new home. Dividing helps a crowded plant perform better.
Here are the steps!
- cut stems to a few inches above the ground
- dig a circle larger than the root
- carefully lift the plant out completely
- shake off excess soil
- divide the clump into sections with at least 3 eyes (buds)
- find a sunny location
- plant the new clump so that the eyes are just 2 inches below the soil line
- mulch for the winter and then remove the mulch in early spring
- transplanted peonies may not bloom to their full potential the first year, but by the second to third they should be back to full glory
This video from garden time, out of Oregon, is a nice visual.