Ornamental · Paeoniaceae
Peony
Paeonia lactiflora
Plant it shallow in full sun, then get out of its way, and a peony will outlast the gardener who set it.
Full sun
Every 7–10 days
USDA 3–8
1–3 ft · 0.3–0.9 m
Overview
Plant a peony and you sign on for one of the longest-lived performers a garden can hold, since a well-placed clump keeps going long after the gardener who set it. It charges back every spring as a herbaceous perennial, throws out big, full flowers in late spring, then carries clean green foliage clear through summer before it dies back for winter. The blooms sweep from soft pinks to clear whites, and plenty of them pack a real fragrance.
Nail two things and a peony practically grows itself: patience and the right planting depth. Bury the eyes too deep and you wait years for a flower that never breaks the surface. Set the depth right, hand it full sun and soil that drains, and it barely needs you after that. Just pick the spot with care, because a peony hates a move and stays put for the long haul.
These plants live for a cold winter, and that works in a grower's favor. A real winter chill triggers the buds, which is exactly why they take off across USDA zones 3 to 8 and stall out where winters stay mild. The growth runs slow and the payoff lands late, but almost nothing else rewards a gardener across so many decades.
Care
The short version: plant your peony in full sun with the buds just 1 to 2 inches deep in rich, free-draining soil, water it about once a week through the growing season, and keep the nitrogen low so it pours its energy into flowers instead of leaves.
Light
Hand a peony full sun, at least 6 hours of direct light a day, and it flowers hard and shrugs off most disease. It puts up with partial shade, but skimp on the light and you hit one of the top reasons a healthy-looking plant simply refuses to bloom.
Water
Soak it deeply about once a week through the growing season, then let the top of the soil dry before the next round. The roots rot in soggy ground, so drainage carries as much weight as the watering does. Keep the spray off the leaves too, since wet foliage rolls out the welcome mat for blight.
Soil
Set it in rich, well-drained soil loaded with organic matter. A pH between 6.0 and 7.0 hits the sweet spot, and the one thing a peony flat-out will not forgive is a wet, poorly drained spot where the roots sit and stew in water.
Humidity
Regular outdoor humidity works just fine, so skip chasing a number. Airflow is the real player here, because still, damp air around packed-in plants is what hands botrytis and powdery mildew their opening.
Feeding
Feed in spring with a low-nitrogen balanced fertilizer, and keep it light. Pile on the nitrogen and you pump out lush leaves instead of flowers, which is the exact opposite of what a peony grower is after.
Pruning
Chop the stems clean to the ground in fall and haul off every scrap of debris, far and away your strongest play against botrytis blight. Deadhead the spent flowers as you go to keep the plant sharp.
Size & spacing
A grown peony climbs to 1 to 3 feet (30 to 91 cm) tall and spreads out about as far. Give each one 1 to 3 feet (30 to 91 cm) of breathing room so air blows through freely and disease loses its grip.
When to plant
A peony clocks in on a fall schedule, not a spring one, so plan around it. Set or divide the roots in September or October so they dig in before the ground freezes, then wait for the big burst of bloom from late spring into early summer, with each plant flowering for about 2 weeks.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Not typically started indoors; propagated by division of dormant roots.
- Plant: Plant or divide roots in September to October so plants establish before winter.
- Harvest: Blooms late spring to early summer (May to early June); individual plants flower for about 2 weeks.
Hardiness
USDA hardiness zones: 3–8
Temperature: down to -40°C
Troubleshooting
Chase almost any peony problem back and it lands on two things, planting depth and damp, crowded air. Catch the early tells on the buds and lower leaves and you can fix the cause before it burns a whole season of bloom. Spot the match below, then jump on it.
Shoots turn black and buds rot under a gray fuzz
Meet botrytis blight, the gray mold that pounces in cool, wet weather and rots young shoots and buds before they ever crack open. Move fast and you shut it right down. Snip out the withered buds and blighted stems the instant they appear, then strip every stalk to the ground in fall so the fungus has zero refuge over winter. Space the plants so air rushes through, and always send the water to the base instead of over the top.
Fix:
- Remove and destroy withered buds, spent flowers, and blighted shoots
- Cut stalks to the ground in fall and remove all debris
- Improve air circulation and avoid overhead watering
Loads of foliage, but no flowers yet
This one comes down to depth almost every time, since a peony eye buried more than 2 inches down just refuses to flower. Shade, a fresh division, or a nitrogen overdose can each stall the blooms too. Here is the move: come fall, lift the crown and reset the buds only 1 to 2 inches under the soil, park it where it grabs at least 6 hours of sun, and give a young or newly split plant a few seasons to build up steam. Fix the depth and the flowers follow.
Fix:
- Replant in fall with buds only 1 to 2 inches below the soil surface
- Move to a site with at least 6 hours of direct sun
- Allow recently divided plants a few years to mature
- Avoid high-nitrogen fertilizers
White powdery dust coats the leaves late in the season
That chalky white coating is powdery mildew, and it pounces once shade and stagnant air roll in, mostly through late summer and fall. It hardly ever kills a peony, but it looks scruffy and saps the plant over time. Rip out and destroy the worst leaves in autumn, open the planting so the air keeps moving, and plant peonies where the sun blazes all day.
Fix:
- Remove and destroy affected leaves in fall
- Improve spacing and air circulation
- Site plants in full sun
Toxicity
A peony earns its keep for the flowers, not the plate, and it carries a compound called paeonol that concentrates in the roots and bark. It runs only mildly toxic, but a pet or grazing animal that chews the roots or stems can wind up with vomiting, diarrhea, and a dull mood. Keep cats, dogs, horses, and small children from gnawing on it and you are set.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Mild
A cat that chews the roots or stems can start drooling, throw up, and walk away from its food. Since the paeonol packs into the parts below ground, it usually takes a real mouthful to spark a reaction, so a stray nibble rarely amounts to much.
Dogs Mild
A dog that digs into the roots or chews the stems can end up vomiting, passing loose stools, and slumping into a dull, low mood. Small nibbles mostly slide by without any drama, so a quick taste is not a crisis.
Horses Mild
A horse that gets into the roots can pick up an upset stomach and diarrhea, often paired with a flat, listless look. It takes a good load of the woody parts to trigger this, so a brief graze rarely does much.
Rabbits Caution
That same paeonol that rattles other animals makes peony a bad match for rabbits, who cannot just empty an upset stomach. Keep the roots and stems out of reach and skip the risk entirely.
Livestock Caution
Cattle, goats, and sheep rarely chase peony down, but the roots carry enough paeonol to upset a grazing animal that does. Fence it off from pasture and everyone stays clear of trouble.
Birds Caution
Records on birds and peony run thin, and the toxin gives no reason to call it safe. Keep a curious pet bird well away from the plant and there is nothing to sort out later.
People Caution
No part of a peony belongs on the plate, and the roots especially can leave you nauseous and queasy if eaten. Grow it for those knockout flowers, and keep small children from chewing on it.
Keep pets from chewing roots and stems; gastrointestinal upset is most likely with large ingestions.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
Peony cultivars run into the thousands, but a few old greats keep grabbing the spotlight. These are the names worth locking in.
Sarah Bernhardt
This classic late double bursts open with fragrant, soft pink flowers right when most other peonies are bowing out.
Do Tell
A standout Japanese-form bloom that rings pale pink guard petals around a punchy, deep rose-pink center.
Festiva Maxima
An old, wildly fragrant double white that flashes the odd fleck of crimson right at the petal center.
How to propagate
Peonies share slowly, but the payoff is huge once you learn the trick: split the dormant root in fall and replant the eyes shallow.
DivisionModerate
September to October while dormant · Several years to reach full bloom after dividing
Turn one peony into several by splitting it in September or October while it rests dormant. Hoist the clump out and slice it so each piece grabs 3 to 5 buds, the eyes, on a hefty chunk of root, then drop those eyes back in just 1 to 2 inches deep. The fresh divisions spend the next few years digging in before they hit full bloom, so plant them, step back, and let them run.
Myths
Peony buds cannot open without ants.
Not so, because the ants show up purely for the sweet nectar the buds pump out, not to pop them open. The buds swing open on their own steam, and the ants do zero damage while they feast. Peonies bloom on their own, ants or no ants.