One of the most popular flowers in the garden, peonies are popular for their large, showy blooms. While the peony flower is not one of the longest lasting blooms, they are certainly one of the showiest flowers, providing your garden with lots of colorful, frilly interest.
Surprisingly easy to grow, particularly as a cut flower, one of the most important aspects of peony care is knowing when to cut back peonies.
Peony flowers can bloom at any point from April to June, depending on where you live and the variety you are cultivating. Knowing when and how to cut back peonies helps to keep the plant healthy and encourages flowering the following year.
The peony is popular for its large, showy flowers.
Why Cut Back Peonies?
There are a number of reasons why you should learn when to cut back peonies.
Pruning plants helps to keep your garden looking neat and tidy. Pruning your plants regularly also has a number of health benefits.
Peony foliage is prone to developing fungal diseases such as powdery mildew. Another common issue is peony leaf blotch. Caused by the Cladosporium paeoniae fungus, this fungal disease can cause glossy brown or purple blotches to form on the upper surface of the plant’s leaves.
While not usually fatal, fungal issues can affect the appearance of the plant. This can be particularly frustrating if you are cultivating showy plants such as the peony. Luckily most fungal problems are easy to prevent.
Pruning helps to keep the peony healthy and productive.
One of the easiest ways to prevent fungal issues from developing is to select a planting location that gets lots of light. Spacing your plants out, so that fresh air is able to freely circulate between the plants also helps.
If left on the ground or on the plant, the spores of both peony leaf blotch and powdery mildew can survive overwinter in dead leaves and infected plant debris. After overwintering the spores can return, attacking your plants again the following spring.
Keeping your garden and soil tidy as well as cutting back peonies in the fall can help to prevent any disease spores or pests from overwintering in your garden.
Remember, after using your garden tools to clean them with Swan 70% Rubbing Alcohol or a disinfectant wipe after using them. Cleaning garden tools helps to prevent the accidental spread of disease from plant to plant as you work your way around your garden.
Should a fungal issue develop, simply cut away and destroy the affected foliage. While healthy foliage and cuttings can be placed on the compost heap, diseased or infected foliage should be placed in your garden waste or destroyed.
Do not place diseased or infected cuttings on the compost heap. Doing so can cause your compost to become diseased. Not only does this ruin your compost, but if infected compost is used on your garden it can lead to other plants becoming diseased.
When to Deadhead Peony Flowers
For many the showy, short lived flowers of the peony are the main attraction of the plant. Some people like to prune the blooms, using them as the centerpiece of a stunning floral arrangement. Other growers prefer to allow the flowers to remain on the plant, filling their garden with showy interest.
Deadhead flowers as they fade.
Often the short lifespan of the flower is further curtailed by the wet spring weather.
Spring winds and rain can knock the peony petals from the flower. Peonies are also prone to falling over in the rain, or just from their weight. A LEOBRO Metal Peony Support Hoop can help to keep the flowers upright and at their best.
If you haven’t snipped your peony flowers for indoor floral displays you will need to deadhead the blooms. This is the first time in the growing season when you need to cut back peonies. Sadly, unlike other annual flowers, deadheading your peony flower doesn’t encourage more blooms to form.
Not only does deadheading help to keep your garden neat and tidy, it is also good for the plant. Allowing spent flowers to remain on the plant causes the peony to waste valuable energy forming seed pods. Deadheading forces the plant to redirect this energy into next year’s foliage and floral display.
To deadhead use a sharp, clean pair of pruners or garden scissors to snip the flower stems where they meet the leaves.
While the spent flowers can be removed you should allow the foliage to remain on the plant into fall.
When to Cut Back Peonies
Knowing when to cut back peonies in the fall is a vital part of caring correctly for the plants. As summer turns to fall, the peony plant can start to look tired and past its best. Late summer and early fall storms can also cause the foliage to fall over, making your garden look untidy.
Do not prune away healthy, green foliage.
It can be tempting to cut back the plant as soon as it starts to look tired, however you should wait until fall before pruning. If you cut back peonies before this, the plant may not have enough energy stored to produce a floral display the following year.
Any foliage that falls over during this period can be tidied up by tying it to a Hydrofarm Bamboo Stake.
Wait until the first hard frost of the year has passed. This should finish off any remaining foliage. Until that point the leaves of the peony can be an attractive golden color, adding interest to fall gardens.
Use a sharp pruning shears or scissors to prune the stems down to around 1 inch above ground level. Be careful not to prune too close to ground level. The top of the crown of the peony sits level with or just below the top of the soil. Damaging this whilst pruning can cause significant harm to the plant. A severely damaged crown may not flower again.
If you are learning when to cut back peonies that are very overgrown or damaged, prune as close to the base of the plant as possible. Make sure that your tools are sharp and clean before starting. Sharp tools enable you to make clean cuts that are less likely to become infected.
When to Cut Back Itoh Peonies
The itoh or intersectional peony is a cross between the herbaceous peony and a tree peony.
These plants can be pruned at the same time as herbaceous peony types. This is explained above.
Prune the itoh peony in the fall.
In addition to removing old foliage, you can prune the herbaceous part of the plant down to the woody section. The woody sections of the Itoh peony should be left intact and not pruned in any way.
When to Cut Back Tree Peonies
Tree peony varieties require less pruning than other types of peony.
Some types of peony require less pruning than other varieties.
The best time to cut back tree peonies is as soon as flowering finishes in the summer.
Unlike herbaceous and Itoh peony varieties, you do not need to wait until the fall before pruning tree peony plants.
You can also lightly prune the plant in the spring, before it flowers.
When you cut back your tree peony, use clean pruners to remove any visible suckers from the base of the plant. You should also prune away any dead wood.
Thin out the tree peony canopy, allowing 5 to 10 of the strongest and healthiest stems to remain intact. The other shoots can be trimmed down to the main trunk with lopping shears. Thinning out helps to improve air circulation around the plant. This helps to prevent issues such as powdery mildew from developing.
If you are training or shaping your tree peony you can also prune away any low-growing foliage. This exposes the trunk, helping to create the desired, visual effect.
When to Cut Back Young Peonies
Newly planted specimens benefit from the removal of their flower buds before they open in the first spring. This helps the plant to establish itself, rewarding you with a fuller, more floral display in following years. However, this is not strictly necessary.
Many growers find themselves unable to wait until the second year before enjoying their peony flowers.
Pruning young plants in the first year can encourage more fuller displays as the plant matures.
Whenever you decide to prune your young peony plants, make sure that you use clean, sharp tools.
When Not to Cut Back Peonies
Do not cut back your peony plants during August or the summer months. Even though flowering has finished for the year, this is an important period in the plant’s life cycle.
During the summer months the peony transfers any energy remaining in the leaves and stem to its below soil tubers. Removing the leaves or pruning too early can prevent this process from happening. If the plant is unable to store enough energy it struggles to grow and flower next year.
Allow the leaves to remain on the plant until they are killed by the first frost of fall or winter. This gives your peony plants lots of time to photosynthesize and store energy.
While you shouldn’t cut back peonies in the summer, you can deadhead spent blooms.
Unless you are cutting any old growth that was left in place the following year do not cut back your peony in the spring. Not only can this harm the plant, it can also deter flowering. The exception to this rule is the tree peony.
Do not cut back peonies in the spring.
What Happens if I Don’t Cut Back Peonies?
Pruning isn’t strictly necessary.
If you don’t cut back peonies the foliage can look unattractive. It also increases the chances of fungal issues developing. However, the plants can still flower the following year.
While the plants can survive without pruning, cutting back peonies once a year helps to keep them healthy and productive. It also keeps your garden looking neat and tidy.
Peony Care Tips
You can grow a peony in the ground, raised bed, planter or even flower pot.
The peony does best in sunny, light positions. However, some types prefer in dappled shade.
The peony is best planted in the fall. You can also plant in the spring but plants may struggle to settle and flower, particularly in the first year.
The peony does best in fertile, well-draining soil.
Before planting amend your soil by working in lots of organic matter such as well-rotted manure or compost. You can also work in balanced, general purpose fertilizers such as fish blood and bone. Apply around 70 g per square meter.
When planting, do not plant your peony too deeply. If planted too deeply your peony may struggle to flower. After planting water well. Continue to keep the plants well watered during the first year to help them settle in their new home.
Once established, despite their showy appearance, the peony is a low maintenance plant. Fairly drought tolerant, you may need to water your plants during prolonged dry spells. The peony also requires a little extra water when the buds are developing.
Plants require extra water when flower buds are developing.
In poorer soils a regular, spring dose of balanced fertilizer helps to promote growth and flowering.
Taller varieties, particularly those planted in an exposed position require staking or some form of support to keep them upright.
After pruning in the fall, add a thin layer of organic mulch such as shredded bark or pine needles to the base of the plant. This helps to keep the crown warm during the winter.
Remember to remove the mulch in the fall.
An alternative to mulch, you can also cover your cut back peony with a Blanket Plant Cover. This cover keeps the plant warm during the winter months, whilst still allowing light and moisture to penetrate the soil.
If you are amending the soil with compost, spread it evenly around the plant. Don’t cover the crown with a thick layer.
Stunning floral displays are the main attraction of the peony.
Different varieties of iris, such as the bearded iris and the Siberian iris are popular companion plants for the peony. The long lasting blooms of these low maintenance plants sit well alongside the showier peony. Roses are another reliable choice. Like the equally compatible camellia, the blooms of the rose compliment those of the peony.
Other companion plant choices include:
In truth, most plants work well alongside the peony. It really is that plant-friendly addition to the garden. As long as they have enough space and light your peony will flourish.
If you want to learn more about cultivating show stopping peony flowers, our How to Grow Perfect Peonies guide is packed with useful tips and advice.
Knowing when to cut back peonies helps to keep your plants looking good. It also encourages them to continue producing show stopping flowers year after year.
Jen is a master gardener, interior designer and home improvement expert. She has completed many home improvement, decor and remodeling projects with her family over the past 10 years on their 4,500 sf Victorian house. She is also a passionate farmer who keeps goats, chickens, turkeys cows and pigs on her farm, and an instructor for her community’s Organic and Sustainable Farming project.