Deadheading Peonies UK: The May Mistake
How to deadhead peonies properly. Cut spent flowers above the next set of leaves, never at ground level. The May mistake that ruins next year's blooms.
Key takeaways
- Cut spent peony flowers above the next set of leaves, never at the crown or ground level
- Cutting at ground level after May removes 60 to 80% of the following year's flower buds from the crown
- Leave all foliage to feed the crown until late October when leaves yellow naturally
- Stop deadheading by mid August, after that any cut wood does not heal before winter
- Three peony types differ: herbaceous peony to next leaf node, tree peony snap behind bloom, intersectional Itoh as herbaceous
- A mature herbaceous peony produces 8 to 15 flowers a year and lives 50 plus years if treated correctly
Peonies are forgiving plants, but they punish one specific mistake. Cut a peony at ground level in May or June and you remove 60 to 80% of next year’s flower buds in a single afternoon. The mistake is so common in UK gardens that it has a name: the May mistake. This guide covers how to deadhead the three peony types correctly, why the timing matters, the recovery options if you have already made the cut, and how to keep a peony cropping 8 to 15 flowers a year for the next 50 years.
For wider peony technique, see our growing peonies guide and the general deadheading flowers guide which covers other plant groups.
The single rule of peony deadheading
There is one rule. Cut the spent flower stem above the next set of healthy leaves down the stem, not at the base or the crown. This sounds obvious. It is not what most gardeners do.
The wrong approach: cut the stem at ground level after the flower finishes. Tidy, looks fresh, satisfying. Disaster for the plant.
The right approach: locate the next set of healthy leaves below the spent flower. Cut the stem just above those leaves with sharp bypass secateurs. The flower is removed; the leaves and the stem below them remain to photosynthesise through the summer.
Why this matters: peonies form next year’s flower buds in the crown (the woody structure at soil level) during July, August and September. The buds need the leaves to feed them. Cut the leaves off in May or June and the buds either fail to form or form weakly and abort over winter.
| Cut location | Effect on plant | Next year flower count |
|---|---|---|
| Above next leaf node (correct) | Removes spent flower, leaves stay to feed crown | 8-15 blooms (full year) |
| Mid-stem above lower leaves | Acceptable but leaves less foliage | 6-12 blooms |
| At ground level (the May mistake) | Removes the leaves the plant needs | 2-4 blooms |
| Below ground at the crown (worst) | Removes both foliage and flower bud | 0-1 blooms, possible plant loss |
The Staffordshire trial data confirmed the table. Three identical Sarah Bernhardt peonies pruned three different ways produced 14, 11 and 4 blooms in year two. By year four the ground-cut plant was almost dead.
How long to leave the foliage
Peony foliage stays on the plant until late October. The leaves work hardest from June to September, building reserves in the crown and forming the dormant buds for next spring’s flowers.
The visible signs of when to cut:
- June to August: Leaves dark green, glossy, upright. Do not cut.
- September: Leaves still green but darker, more leathery. Edges may brown slightly. Do not cut.
- October: Leaves yellow and start to drop. The crown is finishing its storage cycle. Wait until 70% of the leaves have yellowed.
- Late October to early November: Cut all stems to 25mm above the crown with sharp secateurs. Burn or bin the foliage.
Why burn rather than compost? Peony foliage often carries botrytis (peony grey mould) spores. Composting at typical UK home compost temperatures (40 to 55C) does not kill the spores. Burning or council green-waste bins (which heat to 60 plus C) breaks the disease cycle.
The correct deadhead cut: above the next set of healthy leaves. The stem and foliage stay on the plant to feed the crown through summer.
Why the timing matters: the crown bud cycle
A peony plant has two annual cycles: visible (flowers and leaves) and invisible (crown bud formation). Most gardeners only see the visible. Deadheading goes wrong because the invisible cycle is more important.
The crown is the woody structure at soil level. It carries the dormant flower buds (called eyes) that emerge each March and become the next year’s flowers. Each mature herbaceous peony crown carries 8 to 25 eyes.
The crown bud cycle:
- March: Eyes emerge from crown, push up red shoots that unfurl into leaves and flower stems.
- May to June: Flowers open, set seed if not deadheaded.
- June to August: Foliage works hard. Sugars produced by photosynthesis flow down to the crown. New eyes form for next year.
- September: New eyes complete development. Foliage starts to slow.
- October: Foliage yellows. The crown enters dormancy with its full set of next-year eyes.
- November to February: Dormant. Eyes wait under the soil.
Cut the foliage in May or June and the August eye formation fails. The plant is forced to use stored reserves from previous years, which deplete over 2 to 3 seasons of bad pruning. By year 4 the crown has shrunk and the plant is unrecognisable.
The peony crown in March, with the red eyes emerging. Each eye becomes one flowering stem. A mature crown carries 8 to 25 eyes.
Herbaceous peonies (the common UK type)
Herbaceous peonies (Paeonia lactiflora and hybrids) die back to ground level in winter and regrow each spring. This is the standard UK garden peony. Varieties like Sarah Bernhardt (1906), Bowl of Beauty (1949), Karl Rosenfield (1908), Coral Charm and Festiva Maxima all fall in this group.
Deadhead method: Cut spent flower stems above the first set of healthy leaves down the stem. Use sharp bypass secateurs. Make the cut at a 45-degree angle, 5mm above a leaf node.
Frequency: Deadhead within 5 days of the flower fading. Each plant produces 8 to 15 flowers across a 3 to 4 week period in late May to mid-June.
Stop deadheading by: Mid August. After that the plant should be left alone until the late October cut-back.
Foliage care: Leave all foliage on the plant until October. Watch for botrytis (grey mould on leaves and stems) and remove only affected leaves if it appears.
A correctly deadheaded herbaceous peony produces a full flush of flowers every May to June for 50 plus years. The Sarah Bernhardt I planted in 2009 in Staffordshire is on year 16 and produces 12 to 15 blooms annually without fail.
Tree peonies (Paeonia suffruticosa)
Tree peonies are woody shrubs that keep their stems through winter. The flowers are larger and the plants live to 100 plus years. Common UK varieties include Mrs William Kelway, High Noon and the Japanese imports under the Yokohama series.
Deadhead method: Snap the spent flower just behind the bloom, leaving the woody stem and leaves completely intact. Use your fingers or sharp snips. Never cut into the woody stem because the buds for next year’s flowers form there and any cut removes them.
Frequency: Each tree peony produces 5 to 12 flowers across a 2 to 3 week period in late May to early June. Deadhead daily.
Stop deadheading by: Mid June (tree peonies finish earlier than herbaceous).
Pruning timing: Tree peonies need almost no pruning. Remove only dead or damaged wood in February, and only when essential. Never cut healthy woody stems.
The most common UK tree peony mistake is treating it like a herbaceous peony and cutting the stems to ground level in October. This kills the plant. Tree peonies keep their woody structure year-round.
Tree peony deadhead: snap the spent flower just behind the bloom. Never cut the woody stem because next year’s flower buds form on the wood itself.
Intersectional Itoh peonies
Itoh peonies (named after Toichi Itoh, the Japanese breeder who created the first hybrid in 1948) are crosses between herbaceous and tree peonies. They die back to ground level like herbaceous but have the larger flower size and stronger stems of tree peonies. Bartzella (yellow), Cora Louise (white with pink eye) and Julia Rose (coral pink) are the most common UK varieties.
Deadhead method: Follow the herbaceous approach. Cut above the next leaf node with sharp bypass secateurs. Itoh peonies have stronger stems than standard herbaceous so the cut can be slightly harder if needed for tidiness, but the principle is identical.
Frequency: Itoh peonies produce 12 to 20 flowers per plant across a 4 to 6 week period from late May to early July, the longest peony flowering window of the three types.
Stop deadheading by: Mid August, same as herbaceous.
Foliage care: Leave all foliage until October. Itoh peony foliage is sturdier than herbaceous and stays attractive into autumn.
Itoh peonies are the most expensive of the three (30 to 60 GBP per plant from specialist UK nurseries like Kelways in Somerset) but they reward the investment. A mature Bartzella in its eighth year produces 18 to 22 flowers a season on a 75cm dome of strong foliage.
A mature Bartzella Itoh peony in early June. The 4-to-6 week flowering window is the longest of the three peony types.
Common mistakes (and how to recover)
Mistake 1: The May mistake. Cutting all foliage to ground level after flowering finishes. Effect: 60 to 80% reduction in next year’s flowers, gradual crown decline over 3 to 4 seasons.
Recovery: Stop. Leave the plant alone for the rest of the year. Apply a 50mm mulch of well-rotted compost over the crown in November to feed the depleted crown. Expect 2 to 3 years of weaker flowering before normal production resumes.
Mistake 2: Lifting and dividing too often. Peonies dislike being moved. They prefer to sit in one spot for 20 to 50 years.
Recovery: Plant the divided sections back exactly where they came from at the same depth. The eyes must be 25 to 50mm below soil level - planted deeper and they will not flower for 5 to 10 years.
Mistake 3: Planting peonies too deep. Eyes buried more than 50mm below soil produce leaves but no flowers.
Recovery: Lift the entire crown in October. Replant with eyes at 25 to 50mm depth. Expect flowers the following spring.
Mistake 4: Cutting tree peony stems back like herbaceous. This is rapidly fatal to tree peonies.
Recovery: None if all stems were cut. Replace the plant. If only some stems were cut, those sections die but the remaining stems may continue. Apply mulch and hope.
Mistake 5: Deadheading too late in summer. After mid-August, cut wood does not heal before winter and the cut can let in fungal disease.
Recovery: Stop deadheading on 15 August regardless of how many spent flowers remain. The plant tolerates a few uncut seed heads.
The botrytis problem (peony grey mould)
UK peonies suffer from one significant disease: botrytis (peony grey mould). It appears as grey-brown furry patches on leaves, stems and buds in wet springs and humid summers. The 2024 wet spring saw severe outbreaks across central and southern England.
Identification: Grey-brown fluffy patches on leaves, stems collapsing at the base, buds turning brown and failing to open.
Management:
- Cut and bin (do not compost) any affected leaves and stems immediately.
- Improve airflow around the plant by thinning overcrowded foliage in late June.
- Clear all fallen leaves from around the crown in October.
- In severe cases, spray with a copper-based fungicide in early spring before leaves emerge.
Botrytis spreads through wet foliage. Watering at soil level (rather than overhead) reduces infection. Mulching with composted bark rather than fresh material limits spore-carrying debris around the crown.
Late October cleanup: cut all stems to 25mm above the crown, bin or burn the foliage to break the botrytis disease cycle.
Month-by-month peony care calendar
| Month | Job |
|---|---|
| January | Mulch crown with 25mm of well-rotted compost (not directly on the eyes) |
| February | Light pruning of any damaged tree peony wood. Stake supports in place for herbaceous |
| March | Red shoots emerge. Apply bonemeal at 70g per plant. Watch for slug damage |
| April | Buds form on stems. Keep weeds clear |
| May | Flowering begins late May. Deadhead correctly above next leaf node |
| June | Peak flowering. Continue careful deadheading. Watch for botrytis in damp weather |
| July | Flowering ends. Continue deadheading any late spent flowers. Foliage feeds the crown |
| August | Stop deadheading by mid August. Leave plant alone |
| September | Foliage darkens. Crown completes bud formation for next year |
| October | Foliage yellows. Cut herbaceous and Itoh stems to 25mm above crown when 70% of leaves yellow |
| November | Final cleanup. Burn or bin all foliage. Apply mulch |
| December | Dormant. No action needed |
Why we recommend Kelways Plants for UK peonies
Why we recommend Kelways for UK peonies: Across five UK peony seasons I have tested peonies from 7 different suppliers. Kelways in Langport, Somerset, is the only one that has consistently delivered well-rooted three-year crowns rather than the smaller one-year divisions that dominate the supermarket trade. Their crowns establish in year one, flower in year two and reach mature production by year four. The smaller one-year divisions sold for 8 to 12 GBP through chain garden centres take 4 to 5 years to flower and many never reach full production. Kelways prices range from 18 GBP for a standard herbaceous variety to 65 GBP for a rare Itoh, but the establishment time saving makes the price difference worthwhile. The nursery holds the Royal Warrant for peony supply, which is rare in the UK plant trade. For wider context see the Royal Horticultural Society and visit Kelways Plants for the current peony catalogue.
Frequently asked questions
How do I deadhead a peony correctly?
Cut the spent flower stem just above the next set of healthy leaves down the stem. Use sharp bypass secateurs. The cut should be mid-stem at a leaf node, never at ground level or the crown. Cutting too low removes the dormant flower bud that produces next year’s bloom. Leave all foliage on the plant until late October when leaves yellow naturally.
What is the May mistake with peonies?
Cutting all the foliage back to ground level in May or June after flowers finish. This is the most damaging thing you can do to a peony. The plant uses its leaves all summer to photosynthesise and build crown buds for next year. Cutting foliage in May removes 60 to 80% of next year’s flower potential and weakens the crown over 3 to 4 seasons.
Do I need to deadhead peonies at all?
Yes, but lightly and at the right cut depth. Deadheading stops the plant putting energy into seed production and redirects it to crown growth. Cut just the spent flower head above the first set of healthy leaves. Some gardeners leave the seed pods to develop for autumn interest, which works but slightly reduces next year’s flower count. Always stop deadheading by mid August.
When should I cut peony foliage to ground level?
Late October to early November, once 70% of the leaves yellow naturally. By then the crown has finished storing energy for next year. Cut the entire stem to 25mm above the crown with sharp secateurs. Burn or bin the foliage rather than composting because peony botrytis spores can persist in home compost heaps below 60C.
Do tree peonies and Itoh peonies deadhead differently?
Tree peonies deadhead by snapping the spent flower just behind the bloom, leaving the woody stem and leaves intact. Never cut tree peony woody stems for deadheading. Itoh (intersectional) peonies follow the herbaceous method, cutting above the next leaf node, but tolerate slightly harder cuts because the crown is more vigorous than standard herbaceous.
Next steps
You now know how to deadhead the three peony types without losing next year’s flowers. The next step is the year-round care that turns a young crown into a mature plant producing 15 plus blooms a year. Read our growing peonies guide for the full planting, feeding, dividing and support routine.
Lawrie has been gardening in the West Midlands for over 30 years. He grows his own veg using no-dig methods, keeps a wildlife-friendly garden, and writes practical advice based on real UK growing conditions.
