Spring has arrived in most of the continental United States and peonies throughout the land are starting to put out their new growth for the season. We are often asked how to distinguish between new tree peony shoots and advantageous herbaceous graft root suckers. We hope that the pictures below might help to elucidate the difference. A degree of horticultural eye is required, especially when growth is first emerging, so if you are unsure, wait until the new growth has progressed to a point where you can distinguished between the different leaf types of tree and herbaceous peonies before removing any growth.
At Cricket Hill Garden, about half of our tree peonies are propagated by root division while the other half are propagated by grafting onto herbaceous peony rootstock. Some grafted tree peonies, if not planted to a proper depth, are prone to have their herbaceous under-stock sprout, or in horticultural terms, sucker.
Herbaceous under-stock sprouting on a grafted tree peony. Note the distinctive ‘bullet’ shape of the new shoots. A new herbaceous peony shoot will always have fatter and fleshier bud than a new tree peony bud (shown in the next image). If you are unsure of what you are looking at, you can always email us a picture at firstname.lastname@example.org and we will do our best to help you ID the new shoots you are seeing around your tree peonies.
If the new growth around your tree peony looks like that in the above photo, you should remove it. See our past blog post, on how to do this. Before you chop out any new growth, be sure that what you are seeing is not just the tree peony sending up new stems from its own root system, as shown in the picture below.
Own-root tree peonies and grafted tree peonies which have been planted deeply enough will send up new tree peony growth from the root system as they mature. New tree peony growth can be distinguished from herbaceous root-stock suckering its narrower profile.
If you are unsure if the new shoots which you are seeing are tree or herbaceous peony shoots, its best to wait until the first leaves appear. Tree peony leaves will be dissected, while herbaceous peony leaves are more ovate.
Tree peony leaves are highly dissected and usually have three prongs.
Herbaceous peony leaves are ovate and are never dissected.
If you have any questions, about this or any other peony related topic, please email us at email@example.com.