How to Prune Peonies for Stunning Blooms Next Spring

Few sights compare to peonies in full bloom. They're bold, vibrant, and prolific—the definitive showstopper of an early summer garden. But what should you do with your peonies during the other seasons? Pruning is a good place to start. Cutting back not only helps reduce potential disease—it also promotes healthy growth and bountiful blooms. Here, we talked to experts about the how, why, and when of pruning peonies so you'll know exactly where to start. 

Why Pruning Is Beneficial 

You can always leave your peonies intact over the winter, but there are a few good reasons to prune them. "Cutting back peonies is beneficial—it removes the old growth at the end of the growing season," says author and garden historian Jenny Rose Carey. "The peonies start into new growth next spring, and they don't use the old foliage. Removing the old leaves gets rid of any diseases that might be lingering." There's also the aesthetic benefit of eliminating old brown foliage from your garden. 

Cutting back in the fall also has benefits for the next year's growing season. "Herbaceous peonies have foliage and flowers above ground, as well as fleshy storage roots below that provide energy for the next growing season," says Brandon Miller, an assistant professor in the Department of Horticultural Science at the University of Minnesota. "Removing the foliage after the plant has dried down can help reduce disease pressure, like powdery mildew on your plants. It also lets direct sunlight reach the crown, where buds and new growth can be found in the following spring."

When Is the Best Time—and Why?

You certainly don't want to prune your peonies in spring when they're first putting on the year's growth—or during the early summer when they're at the height of full bloom. "The best time to remove the leaves is in late summer or early fall—or as soon as the leaves look unattractive or diseased," says Carey. "We usually cut them down in September so that other things in the border have space to grow in the autumn. Prior to that, the foliage adds general leafiness and helps to support surrounding plants."

It's also possible to prune in the very early spring. "Herbaceous peonies can be pruned to the ground when the foliage and stems are no longer green and appear to have dried down," says Miller. "This naturally happens in autumn, so pruning can take place in late fall or in early spring, well before new growth emerges."

What You'll Need 

Cutting back peonies isn’t a major undertaking, and the tools you'll need to get the job done are minimal. 

• Bypass pruners: Nothing special, just a nice pair that's capable of making a clean, sharp cut. 
• Pruner cleaner: It's a good idea to clean your pruners to help control the spread of potential plant disease. "We use an alcohol spray bottle to sanitize the clippers between each peony plant," says Carey. It’s simple and only takes a moment, but can save you headaches later on.
  

How to Prune

Here’s some good news: pruning peonies isn't difficult. Here are some steps to follow:

1. Cut the Stems

"Using clean, sharp bypass pruners, cut through each stem close to the ground and discard the detached foliage," says Miller. It’s sometimes helpful to have a garden rake on hand too, to collect your clippings or to remove foliage that's significantly deteriorated. 

2. Beware of the Crown

"Ensure pruning cuts don't damage the crown of the plant, which hosts the buds for the following season's growth," says Miller. "The perennial crown is located at soil level, or just below the surface of the soil."

3. Leave a Small Amount

Herbaceous peonies can be cut back to about an inch as soon as the peony foliage looks bad, as per Carey.

Things to Look Out For

Pruning peonies is a relatively straightforward process, but there are some common mistakes and need-to-knows that will make or break your experience. Here's what to keep an eye out for.

Know Your Peony Species

While it’s likely you have herbaceous peonies, you might have a type with permanent growth that's handled differently. "If you grow peonies that have woody stems—like tree peonies—then don't cut into the part of the aboveground structure that has bark," says Carey. "In mild climates, and in sheltered positions, tree peonies can grow into a large, shrub-like structure. In harsher climates, they may grow a couple of feet. Cut back only the soft tissue and don't cut the woody parts." 

Watch for Middle-of-the-Road Varieties

"Intersectional, or Itoh peonies, as the name suggests, are somewhere in between [woody and herbaceous]," says Carey. "Depending on your climate and growing conditions, these peonies may or may not develop a woody stem. If they die back down to the ground, cut them back all the way like a herbaceous peony. If they make a woody stem, cut back above that."

Be Careful Not to Accidentally Spread Disease

It's possible to spread plant diseases around when you're pruning your peonies or disposing of the decayed plant material, so take care to prevent this. "Carefully remove the foliage and dispose of it into municipal composting if you have one, rather than your own compost heap, which doesn't usually get hot enough to kill the fungal spores," says Carey.

Remember to Be Patient

"Don’t prune your plants too early," says Miller. "Waiting until the leaves are clearly no longer green and have dried down in the fall ensures the plant is adequately prepared for a winter dormancy. After flowering, the foliage continues to photosynthesize and generates energy, which is stored in the roots. This leads to healthy plants and blooms in the following season."