Remove and compost all the cut material so it can’t host any of the pests and problems that can affect peonies, then mulch around the roots with well-rotted manure or compost (homemade if possible).

You’ll want to cut about 3-5cm off to get rid of the ... sure you're planting them in the best conditions. For peonies with bare roots, you should plant them as soon as you get them home ...