Ornamental · Paeoniaceae
Peony
Paeonia lactiflora
Plant it shallow in full sun, then leave it alone, and your peony will probably outlive you.
Full sun
Every 7–10 days
USDA 3–8
1–3 ft · 0.3–0.9 m
Overview
Here's a plant that sticks around: the peony is one of the longest-lived things you can put in the ground, and a happy clump can easily outlast the person who planted it. Every spring it pops back up as a herbaceous perennial, opens big, full flowers in late spring, and then keeps clean green leaves all summer before it dies back for winter. The blooms go from soft pinks to clear whites, and a lot of them actually smell wonderful.
So what does a peony really want? Patience, and the right planting depth. Bury the eyes too deep and you'll be waiting years for a flower that never shows up. But get the depth right, give it full sun and soil that drains, and honestly it barely needs you after that. Just pick the spot carefully, because a peony hates being moved, so wherever you put it is pretty much where it'll live.
These are cold-weather plants down to their roots. They need a real winter chill before they'll set buds, which is why they're so happy across USDA zones 3 to 8 and kind of sulk where the winters stay mild. Sure, the growth is slow and the payoff takes a while, but not many perennials will keep thanking you for this many decades.
Care
The short version: give your peony full sun, tuck the buds just 1 to 2 inches deep in rich soil that drains well, water it about once a week during the growing season, and go easy on the nitrogen so you get flowers instead of a pile of leaves.
Light
Give a peony full sun, which means at least 6 hours of direct light a day, and it'll flower like a champ and shrug off most disease. It'll put up with partial shade, but too little sun is one of the top reasons a perfectly healthy-looking plant just won't bloom.
Water
Water deeply about once a week through the growing season, and then let the top of the soil dry out before the next drink. The roots rot in soggy ground, so drainage matters just as much as the watering does. And keep the spray off the leaves, since wet foliage is basically an invitation to blight.
Soil
Plant it in rich, well-drained soil with lots of organic matter worked in. A pH somewhere between 6.0 and 7.0 is ideal, and the one thing a peony absolutely won't forgive is a wet, poorly drained spot where the roots just sit there in water.
Humidity
Regular outdoor humidity is totally fine, so there's no magic number to chase here. What matters way more is good airflow, because still, damp air around crowded plants is exactly what lets botrytis and powdery mildew move in.
Feeding
Feed it in spring with a low-nitrogen balanced fertilizer, and don't overdo it. Too much nitrogen just pushes out leafy growth instead of flowers, which is the last thing you want from a peony.
Pruning
Cut the stems all the way down to the ground in fall and clear out every scrap of debris, because that's hands down the best thing you can do against botrytis blight. And deadhead the spent flowers as you go to keep the plant looking tidy.
Size & spacing
A grown peony hits about 1 to 3 feet (30 to 91 cm) tall and spreads roughly as wide. Give each one 1 to 3 feet (30 to 91 cm) of elbow room so air can move freely and disease has a harder time getting started.
When to plant
Peonies run on a fall schedule, not a spring one, which trips up a lot of folks. Set or divide the roots in September or October so they can settle in before the ground freezes, and then you'll get the big flush 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
Almost every peony problem comes back to two things: how deep you planted it, and whether the air around it is damp and crowded. Catch the early signs on the buds and lower leaves, and you can usually sort out the cause before it eats a whole season of bloom. Find what matches below, then go from there.
Black shoots and rotting buds with a gray fuzz
That's botrytis blight, a gray mold that loves cool, wet weather and rots the young shoots and buds before they even open. The good news? It's easy to knock back if you don't let it linger. Snip off the browned buds and blighted stems the second you spot them, and clear every stalk to the ground in fall so the fungus has nowhere to hide over winter. Then just give the plants some breathing room and water at 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
Plenty of leaves, but where are the flowers?
Nine times out of ten it's the depth, because a peony eye buried more than 2 inches down just won't flower. Too much shade, a recent split, or a big dose of nitrogen can all keep the blooms away too. So here's the fix: in fall, lift the crown and set the buds only 1 to 2 inches under the soil, give it at least 6 hours of sun, and cut a young or freshly divided plant some slack for a few seasons.
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
A white powdery coating late in the season
That dusty white film is powdery mildew, and it tends to move in once shade and still air give it an opening, mostly in late summer and fall. It won't usually kill a peony, but it does look rough and it wears the plant down if it keeps coming back. Just pull and toss the worst leaves in autumn, open things up so air can move through, and keep your peony in full sun.
Fix:
- Remove and destroy affected leaves in fall
- Improve spacing and air circulation
- Site plants in full sun
Toxicity
A peony is a flower to look at, not a snack, and it carries a compound called paeonol that's most concentrated in the roots and bark. It's only mildly toxic, but a pet or grazing animal that chews the roots or stems can end up with vomiting, diarrhea, and a dull mood. So just keep cats, dogs, horses, and small children from gnawing on it.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Mild
If a cat chews on the roots or stems, you might see some drooling, a bit of vomiting, and a cat that suddenly isn't interested in dinner. The paeonol is mostly down in the roots, though, so it usually takes a real mouthful before anything happens.
Dogs Mild
A dog that goes digging at the roots or chews the stems can end up with vomiting, loose stools, and a kind of flat, gloomy mood. A little nibble here and there? That tends to pass on its own without any drama.
Horses Mild
A horse that gets into the roots can wind up with an upset stomach and diarrhea, and often looks pretty listless while it's at it. It does take a fair bit of the woody parts to cause trouble, so it's not a hair-trigger thing.
Rabbits Caution
The same paeonol that bothers everything else makes peony a bad bet around rabbits, and a rabbit can't just throw up whatever upsets it. So play it safe and keep the roots and stems out of reach.
Livestock Caution
Cattle, goats, and sheep probably won't go looking for peony, but the roots pack enough paeonol to upset a grazing animal that does. Easiest thing? Fence it off from the pasture and don't think about it again.
Birds Caution
There's not much on record about birds and peony, and the toxin doesn't give any reason to assume it's fine. So keep a curious pet bird well away from the plant, just to be sure.
People Caution
No part of a peony belongs on your plate, and the roots especially can leave you nauseous and queasy if you eat them. Grow it for the flowers, and don't let small children chew 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
There are thousands of peony cultivars out there, but a few old favorites keep showing up. These are the ones worth knowing by name.
Sarah Bernhardt
This old favorite is a late double that opens its fragrant, soft pink flowers right when most other peonies are already calling it a year.
Do Tell
It's a Japanese-form flower, so you get pale pink guard petals wrapped around a rich, deep rose-pink center.
Festiva Maxima
This one's an old, seriously fragrant double white that every so often shows a little fleck of crimson right in the middle of the petals.
How to propagate
Peonies are slow to share, but it's simple once you know the trick: split the dormant root in fall and replant the eyes nice and shallow.
DivisionModerate
September to October while dormant · Several years to reach full bloom after dividing
Want more peonies? Split one in September or October, while it's sitting dormant. Dig up the clump and cut it so every piece keeps 3 to 5 buds, the eyes, on a good solid chunk of root, then replant those eyes just 1 to 2 inches deep. The new divisions take a few years to really settle in before they bloom their best, so plant them and then leave them be.
Myths
Peony buds won't open unless ants help them.
Nope, the ants are just there for the sweet nectar on the buds, not to pry anything open. The buds open just fine on their own, and the ants don't hurt a thing while they're snacking. So peonies bloom either way, ants or no ants.