It can't get much better than the scent of peonies filling your yard in spring. Renowned for producing large, open flowers, few plants offer such a vast range of forms and colors as peonies, from purest white to lemon yellow, softest pink to deepest red.
While you might already know how to grow peonies, knowing how to prune peonies and when to cut them back is an essential garden task, particularly if you want to keep your plants in good health and ensure maximum blooms next year.
Here, garden experts reveal how best to prune and cut back your peonies, the right approach to take, and the best time to trim. So, before you reach for your pruning shears, make sure you read our guide to guarantee brilliant blooms next year.
When to cut back peonies – a quick look:
The type of peony you're growing will determine when you need to cut it back.
Herbaceous peonies should be cut back in fall, between October and November. This should be after the first frost and when the foliage has turned yellow. You should aim to cut peonies back to around an inch from the ground. This will help keep your peony plant healthy and free of disease when the blooms return next spring.
If you're growing a tree peony, pruning can be done in fall or spring. In fall, remove spent flowers and cut back top growth by about a third. Tree peonies are often grafted onto herbaceous peony rootstock, so take care not to prune them right back. In spring it can be a good idea to cut back tree peonies before new growth. This can encourage a boost of growth but may also sacrifice some flowers for the season.
Alternatively, you can also leave some fading peony flowers in fall to harvest peony seeds.
When is the best time to trim peonies?
Peonies grow best in US hardiness zone 3 to US hardiness zone 9. The type of peony you're growing and your local climate will determine when to cut back peonies. Those gardeners living in warmer, southerly zones will notice that their peonies flower much earlier than those in cooler zones.
‘Renowned for their oversized blooms, peonies are a prized landscape plant often used for cut flowers,’ says Lindsay Pangborn, garden and plant expert. ‘Cutting back peonies is a critical to-do item, but it’s important to think about timing. It’s a careful balance of aesthetic and plant health considerations.’
When to cut back herbaceous peonies
It may be tempting to prune peonies as soon as the leaves start looking yellow or brown, which can happen in the summer, you must wait until fall to prune them. One of the most common peony pruning mistakes is pruning too early.
That's because your peonies need their foliage to produce energy for next year's growth. Cutting them sooner could affect next year's flowers, which you want to avoid at all costs.#
'Proper fall peony pruning is a good practice, as fungal diseases such as powdery mildew can survive on dead leaves throughout the winter, only to re-emerge and infect the new growth the following spring,' says Meredith Bishop, sustainable flower grower and owner of Bloom and Bounty.
When fall sets in, usually around October to November, your peony foliage will fade and wilt. It is then time to trim.
‘Cut your peonies back to about 1 inch (2.5cm) above the ground,’ says Jennifer Green, botanist and expert at Positive Bloom. ‘As a herbaceous perennial, peonies will die back only to re-emerge next spring, so do not worry about cutting them too harshly.'
Remember to always use clean, sharp essential gardening tools, such as these pruning shears available from Walmart.
'Do not be tempted to trim too early,' says Jennifer. 'August is not the best time to cut back peonies, as it doesn’t allow the foliage to absorb as much energy as it needs for the following year.'
The foliage of peonies tends to fade and wilt from August, and although the leaves may not look great, it is best to allow your plant to photosynthesize as much as possible and gather energy for next year's blooms.
When to cut back tree peonies
Unless you are trimming old growth left over from the previous year, you must not cut back your peonies in the spring, as this could harm the plant and prevent it from flowering.
The only peony you should trim in the spring is a tree peony. For those gardeners who don't know how to grow a tree peony, it's important to know that you wouldn't cut back tree peonies in the fall like you do a herbaceous peony. Early spring is the best time to prune tree peonies.
You should also only remove spent flowers from a tree peony and cut back not more than a third of the plant, as these plants are usually grafted onto herbaceous peony rootstock and cutting them right back may affect their growth habit.
Spring is not only time to cut back tree peonies, but also time to fertilize your peony plants. 'Peonies benefit from an application of blood meal and bone meal in early spring, just as the shoots are beginning to emerge from the ground,' says Meredith.
Shop pruning accessories
These Felco pruning shears will make easy work of all your garden jobs, quickly and effectively trimming perennials and shrubs in the yard.
Garden gloves are essential to protect your hands from sharp thorns and jagged stones in the soil.
Protect yourself on those hot days in the garden. This sunhat will allow you to keep working and keep your head sheltered from the sun.
FAQs
What happens if you don't cut back peonies?
If you don’t cut back peonies, the old foliage will become unsightly over the winter and into the spring, but they should still flower the following year. If you can trim your peonies, it is important to do so as it can protect against fungal disease.
Knowing when to cut back peonies is a crucial part of peony care in the yard. After deadheading your peonies, don't be scared to cut herbaceous peonies right back in fall to boost new growth in spring. But be sure to only trim your prized peonies at the right time, otherwise you risk a reduction in blooms the following year.
