Cooperative Extension: Garden and Yard

The best time to transplant peonies is in late August or early September. Unlike most perennials, they should only be divided or transplanted every 10 years or so and often don’t need to be transplanted or divided for decades. Be sure to use a sharp spade to make a clean cut around the root mass and replant it the same depth as was naturally growing in the original space. The University of Minnesota Extension has a terrific bulletin on dividing perennials. Even though you might not be dividing this plant, many of the concepts still apply.