Peony flowers may only last a short time, but their stunning, colorful blooms make them deserving of a space in any perennial garden. These richly symbolic plants don’t ask for much in terms of maintenance but do grow best with an annual prune. Follow this guide to find out when and how to cut back your Peonies.
When Do You Cut Back Peonies? Key Takeaways
Herbaceous and Itoh Peonies are cut back in fall, while tree Peonies are best pruned in spring. Wait until the first frost hits before cutting the stems down to the crown, or to the woody growth in the case of intersectional Peonies. Deadheading should be done throughout the flowering season but will not encourage a second round of blooms.
Is Pruning and Deadheading Peonies Necessary?
The annual task of pruning is one some gardeners look forward to but that many others dread. If you’re in the latter camp, you may wonder whether pruning is necessary for Peonies or whether they can get by without it.
For most plants, pruning is not absolutely needed. After all, they have evolved over hundreds, if not thousands of years in the wild, growing just fine without any home gardeners coming by to cut them back.
But, just because your plants will survive without an additional prune, it doesn’t mean they will thrive.
Pruning has several benefits for Peonies and for your garden overall:
Pest and Disease Prevention
As Peonies die back in fall, their limp foliage can attract garden pests and diseases that may damage your plant and kill the roots (peony roots can also freeze in winter) before new stems have a chance to emerge the following spring.
Pruning clears the area, eliminating all the hiding spots where pests and diseases can settle. This protects your Peonies for the next season and protects nearby plants from incurring the same pest and disease problems.
Peonies can withstand bouts of cold weather well. However, if you live in a region with extreme winters and plenty of snow, your Peony might need some extra maintenance and protection.
You can leave your plant to die back naturally and cover the area. However, pruning the dead foliage away will give you a closer look at the crown to assess plant health. Plus, you get a clean bed to add a healthy layer of mulch that protects the crown through the worst of the cold.
Few gardeners can withstand an untidy garden for an entire season. We want our beds to look their best year-round, not just spring and summer. When Peonies die back, they cover beds with yellowed foliage that completely ruin a landscape if in full view.
You can remove these unsightly eyesores and keep the area looking clean by pruning. A clean bed is also better for plant health and provides the best foundation for new growth when the peony soil warms.
Deadheading – cutting back flower heads once they have finished blooming – is another part of ornamental garden care. It improves the overall look of the plants and can encourage more blooms to emerge in certain plants.
Unfortunately, deadheading won’t produce a second round of blooms in Peonies. Their short season of first flowers is the most you’ll get from them.
However, deadheading will still improve the overall look of your plants, especially if you have a variety of large flower heads.
Simply cut back the blooming stem once the flowers have changed color to deadhead. Deadheading peonies early on in the peony blooming season can also direct more energy into the later flowers and the foliage rather than seeding.
When Should You Prune Your Peony?
Types of Peonies
Pruning time and technique will differ based on the type of Peony you have.
These plants are split into three categories:
- Herbaceous: The most commonly grown type, also known as the perennial Peony. This group includes the popular species Paeonia officinalis and Paeonia lactiflora. They flower from May to June on fleshy, herbaceous stalks.
- Tree: These species form woody shrubs, producing earlier flowers that stay in bloom longer than their herbaceous counterparts. They grow several inches each year and can reach up to 7 feet tall.
- Itoh or Intersectional: Developed by horticulturist Toichi Itoh from Tokyo in 1948, this hybrid has herbaceous characteristics and tree-like leaves. They also produce many large flowers on one plant – as many as 50 per season.
Pruning Herbaceous Peonies
While many ornamental plants can be pruned as soon as they finish flowering, that is not the case for Peonies.
These plants need all the leaves they can get after flowering. They continue to photosynthesize and store energy in the crown until the leaves die back, giving them enough to survive winter and pop up again the following spring.
Herbaceous Peonies should only be cut back in fall – never spring – once the leaves begin to turn yellow or brown. This usually occurs after the first frost hits, which will differ depending on your region. Check your local resources for your area’s frost dates.
There is no harm in leaving the foliage until fall as the leaves change color from a glossy green to golden along with the rest of your garden. Even if some of the leaves are damaged, don’t prune anything back until that first frost to give your plant all the winter storing energy it can get.
Pruning Itoh Peonies
Due to their similar characteristics, intersectional Peonies should be pruned simultaneously as herbaceous Peonies.
However, the technique differs slightly.
While herbaceous Peonies are cut back to the ground, Itoh Peonies should be trimmed down to where the woody growth begins. The herbaceous parts will naturally die back, giving you a clear indication of where to trim when the leaves start to yellow in fall.
Pruning Tree Peonies
Tree Peonies are pruned on an entirely different schedule. This type does not die back over the winter and retains its foliage year-round (unless the temperatures dip too low).
The best time to prune these plants is in early spring, before flowers start to emerge. This prune is mainly to direct the plant’s energy into producing new flowers rather than new branches or leafy growth.
Of all the Peony types, tree Peony pruning is the least necessary but still impacts growth, health, and flowering in the long term.
When Should You Deadhead a Peony?
As with other flowering plants, deadheading should be done throughout the flowering season. For tree types, this will be April to May, and for herbaceous or Itoh types, May to June.
Remove all the spent flowers as soon as they start to change color or become damaged. You can also remove them sooner to bring them indoors and enjoy them as cut flowers.
As the flowering season is short, especially for popular herbaceous types, you won’t need to deadhead very often. It can typically be done once or twice in large batches toward the end of the flowering period.
How to Cut Back or Prune Peonies
Before starting, gather your pruning shears and clean them with soap and water or a 5% bleach solution if you have recently handled plants with diseases. Dirty tools can spread harmful bacteria that cause disease in your precious plants.
For herbaceous Peonies, cut all the foliage and stems down to the ground. Be careful not to cut too close to the crown (the fleshy section above the roots), as this can leave it vulnerable and unprotected over the cold winter.
If you live in a region with freezing winters, add a layer of mulch over the crown once you’ve finished pruning to protect it until spring.
Cut intersectional Peonies back to the point where the woody growth ends, removing all herbaceous growth. These parts will die back after the first frost, giving you a good indication of where to cut.
In spring, remove any suckers from the lower branches of your tree Peony to improve upward growth and direct energy toward flowering. At the same time, remove any damaged or diseased branches that may sap energy away from healthy growth.
Once you’ve finished cutting back, throw the leaves and stems on the compost heap. Alternatively, if they show any signs of disease, destroy them to avoid spreading the problem.
Peonies aren’t high maintenance plants, requiring little attention from you throughout the year if you can provide them with a sunny spot to enjoy. Depending on the type, a yearly prune, either in fall or spring, is all they ask for to look their best and flower reliably year after year.