When to cut back peonies: Time your pruning to help next year’s blooms

After the first spring bulbs appear, the blooms I look forward to with the most anticipation in the spring are peonies. I love when I finally spot those big flower buds getting ready to burst open and reveal all the frilly petals they’ve been holding in. Knowing when to cut back peonies will ensure those beautiful blooms reappear next spring. Luckily once the flowers die back, you’re left with nice, strong foliage that will provide a backdrop for subsequent blooms.

Peony season, which can be anywhere from April to June, depending on where you live, can be fleeting. Those blooms that bring such colour and personality to the spring garden sure don’t like to hang around for long. But when shopping for peonies at the garden center, you can find early-, mid-, and late-season bloom times. Check the plant tag for details. I have a few peonies and luckily they don’t all open at once. They are staggered about a week or so apart, so I get to enjoy peony flowers for longer.

When to deadhead peonies

Hopefully you get to enjoy the flowers before a spring storm makes a mess of them. I’m often picking up sad-looking, bruised petals after a storm, lamenting the fact that the flowers seem to have just opened. Rain can make quick work of them, turning the petals into a bit of a mushy mess. If you find your peonies flop from their weight (or from a heavy rainfall), try placing a peony hoop over the plant, early in the spring, while it’s still easy to do so.

If your peony blooms don’t make it inside for cut flower arrangements, you can deadhead the faded flowers once they’re past their prime. This step, unfortunately, doesn’t encourage more flowers, like on other annuals and perennials.

It’s also worth noting that allowing the seed heads to form on spent blooms will affect next year’s growth. Deadheading right after the plant blooms allows it to redirect all of its energy into next year’s growth and blooms. Right after deadheading is also a great time to fertilize peonies, too.

To deadhead a peony, use a sharp, clean pair of pruners to snip the flower stems where they meet the leaves. As for the foliage, you’ll want to leave it standing in the garden well into autumn. The rest of this article will explain why you should leave your herbaceous peony foliage until fall.

When to cut back peonies

Throughout the season, your peony leaves may start to look less than stellar. And though it could be tempting to cut them back, the plant relies on the energy from the leaves for the following year’s new growth. That’s why you need to wait until fall to prune them back. Cutting them back sooner could affect next year’s flowers.

For example, peony foliage can be prone to powdery mildew, which won’t kill the plant, it just looks unsightly. Full sun and lots of space to promote air circulation can help to prevent powdery mildew. Other afflictions can include botrytis blight, verticillium wilt, and Japanese beetles.

Knowing when to cut back peonies in fall is key. Timing-wise, wait until a hard frost has finished off the foliage. (Where I live, that’s usually around October, but some years it’s November.) Until that point, peony leaves are quite lovely in early fall, changing color—usually to a golden hue—like other trees and shrubs.

Using a sharp pair of pruning shears, prune back all the stems right to ground level. Be gentle with the soil around the base of the plant. You want to be careful not to damage the crown at the soil level.

Why it’s important to cut back peony plants

On this site, we talk about the reasons why gardeners should save the fall garden cleanup until spring. Peonies, however, are exempt from this rule. They’re one of those plants you should cut back, especially if you have had disease issues throughout the growing season. Cutting back a peony will help to prevent pests and diseases from harming the plant. Be sure that once you’ve pruned everything back, you remove all the plant debris from the area, including any leaves that may have fallen. Discard the trimmings—diseased leaves or insect-ravaged stems—right into the garbage, not the compost pile.

If you live in an especially cold climate, add a light layer of mulch (such as shredded bark or pine needles) at the base of the plant where you cut everything back. Be sure to remove your winter mulch in the spring. If you’re amending the soil around your peony with compost—plants prefer well-draining soil—don’t pile it on the crown, add it around the perimeter.

When to cut back Itoh and tree peonies

Itoh (or intersectional) peonies, which are a cross between the herbaceous peonies mentioned in this article and tree peonies, should follow the same pruning schedule. However in this case, prune the herbaceous part down to the woody party, which you should leave intact.

The best time to prune a tree peony is right after it blooms. Do not cut it back in the fall as you would an herbaceous or Itoh peony. You can do a light pruning in the spring before the shrub blooms. Use clean pruners to remove suckers around the base, as well as any dead wood.

To see how peonies should be cut back and hear about different timing options, check out this video:

More pruning advice

• Tips for pruning lilacs
• The best time of year to prune a rose of Sharon
• Viburnum pruning: Early summer is the time to prune spring-blooming shrubs
• When to cut back irises for healthier, more attractive plants