Ornamental · Paeoniaceae
Peony
Paeonia lactiflora
Set it shallow in full sun, then step back and let it be, and your peony may well outlive you.
Full sun
Every 7–10 days
USDA 3–8
1–3 ft · 0.3–0.9 m
Overview
If you want a plant that rewards a little patience with a lifetime of flowers, a peony is a wonderful place to start. It is one of the longest-lived things you can put in the ground, and a happy clump can carry on long after the gardener who planted it. Each spring it rises again as a herbaceous perennial, opens big, full blooms in late spring, then keeps clean green leaves all summer before resting through winter. The flowers range from soft pinks to clear whites, and many of them are truly fragrant.
Here is the reassuring part: a peony asks mostly for patience and the right planting depth, both of which are easy to get right. Set the eyes too deep and you may wait years for a flower, but settle them just so, offer full sun and soil that drains, and the plant needs almost nothing else from you. The one thing to remember is that a peony dislikes being moved, so choose its spot with a little care and it will happily stay put for good.
At heart these are cold-climate plants, and that works in your favor. They need a genuine winter chill to set their buds, which is why they do so well across USDA zones 3 to 8 and only sulk where winters stay mild. Growth comes slowly and the payoff arrives in its own time, but few perennials will thank you so faithfully, for so many years.
Care
The short version: give your peony full sun, tuck the buds only 1 to 2 inches deep in rich soil that drains freely, water about once a week through the growing season, and keep the nitrogen low so it puts its energy into flowers rather than leaves.
Light
Give your peony full sun, meaning at least 6 hours of direct light each day, and it will flower generously and shake off most disease. It will get by in partial shade, but too little sun is one of the kindest explanations for a healthy-looking plant that just will not bloom.
Water
Water deeply about once a week through the growing season, then let the top of the soil dry a little before the next drink. The roots rot in soggy ground, so good drainage matters every bit as much as the watering does. Keep the spray off the leaves, since wet foliage tends to invite blight.
Soil
Plant in rich, well-drained soil with plenty of organic matter mixed in, and your peony will feel right at home. A pH between 6.0 and 7.0 suits it nicely, and the one thing it truly will not forgive is a wet, poorly drained spot where the roots have to sit in water.
Humidity
Ordinary outdoor humidity is perfectly fine, so there is no number to fuss over here. Good airflow matters far more, because still, damp air around crowded plants is exactly what lets botrytis and powdery mildew move in.
Feeding
Feed in spring with a low-nitrogen balanced fertilizer, and go gently. Too much nitrogen coaxes out lush leaves at the cost of flowers, which is the last thing you want from a peony you are hoping to see bloom.
Pruning
Cut the stems right down to the ground in fall and clear away every scrap of debris, which is far and away the best thing you can do against botrytis blight. Deadhead the spent flowers through the season to keep the plant looking neat.
Size & spacing
A grown peony reaches 1 to 3 feet (30 to 91 cm) tall and spreads out about as far. Leave each plant 1 to 3 feet (30 to 91 cm) of room so the air can move freely around it and disease has less chance to settle.
When to plant
A peony keeps a fall schedule rather than a spring one, and that makes the timing simple. Set or divide the roots in September or October so they can settle in before the ground freezes, then look forward to a generous 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
Nearly every peony worry comes back to two gentle causes, planting depth and damp, crowded air. Learn to read the early hints on the buds and lower leaves and you can usually put things right before a season of bloom slips away. Find what matches below, then take one small step at a time.
Blackened shoots and rotting buds under a gray fuzz
What you are seeing is botrytis blight, a gray mold that arrives in cool, damp weather and spoils young shoots and buds before they can open. Take heart, because catching it early makes all the difference. Snip away the browned buds and blighted stems as soon as they appear, and clear every stalk to the ground come fall so the fungus has no home for winter. Leave a little space between plants for the air to move, and pour water at the base rather than 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
Lots of green leaves but hardly any flowers
Try not to worry, because this one is almost always fixable. Most often the eyes simply went in too deep, and a peony bud set more than 2 inches down struggles to ever flower. Shade, a fresh division, or too much nitrogen can hold blooms back as well. In fall, lift the crown gently and settle the buds only 1 to 2 inches under the soil, find it a spot with at least 6 hours of sun, and give a young or newly split plant a few kind seasons to find its feet.
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 film on the leaves late in the year
This dusty white coating is powdery mildew, and it tends to settle in once shade and still air give it a foothold, mostly through late summer and fall. The good news is that it rarely does a peony real harm, though it does look tired and can wear the plant down over time. Gather up and dispose of the worst leaves in autumn, open the planting 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 grown for its lovely flowers, not for the table, and it holds a compound called paeonol that gathers most in the roots and bark. It is only mildly toxic, so there is no need for alarm, but a pet or grazing animal that chews the roots or stems can come down with vomiting, diarrhea, and a dull mood. A little care to keep cats, dogs, horses, and small children from gnawing on it is all it takes.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Mild
Should a cat gnaw at the roots or stems, you might notice drooling, a bout of vomiting, and a lost appetite. Because the paeonol sits mostly below ground, it usually takes a fair mouthful to bring on a genuine reaction, so a curious nibble is rarely cause for panic.
Dogs Mild
A dog that digs into the roots or chews the stems may end up with vomiting, loose stools, and a quiet, dull mood for a while. Small tastes tend to move through without much bother, so a little grazing is nothing to lose sleep over.
Horses Mild
A horse that gets into the roots can suffer an upset stomach and diarrhea, often looking flat and low in spirits. It does take a good helping of the woody parts to set this going, so the risk stays modest.
Rabbits Caution
The very paeonol that unsettles other animals makes peony a poor pick around rabbits, whose tummies cannot simply empty out trouble. Kindest to tuck the roots and stems well out of reach and spare them the risk.
Livestock Caution
Cattle, goats, and sheep will seldom go looking for peony, yet the roots hold enough paeonol to upset a grazing animal that does. A simple fence between the plant and the pasture keeps everyone comfortable.
Birds Caution
There is little written down about peony and birds, and the toxin gives no reason to call it safe. To be gentle and sure, keep an inquisitive pet bird away from the plant.
People Caution
No part of a peony belongs on the dinner plate, and the roots especially can bring on nausea and a sore stomach if eaten. Enjoy it for the flowers, and steer small children away 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, yet a handful of old favorites keep coming up year after year. These are the ones well worth learning by name.
Sarah Bernhardt
This much-loved late double unfurls its fragrant, soft pink flowers just as most other peonies are winding down for the year.
Do Tell
A charming Japanese-form flower that sets pale pink guard petals around a warm, deep rose-pink heart.
Festiva Maxima
A treasured old double white, wonderfully fragrant, that shows the odd fleck of crimson tucked into the center of its petals.
How to propagate
Peonies are slow to share, but the trick is friendly and simple once you know it: divide 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
You can split a peony in September or October, once it has gone quietly dormant. Ease the whole clump out of the ground and cut it so each new piece keeps 3 to 5 buds, the eyes, on a good solid piece of root, then tuck those eyes back in just 1 to 2 inches deep. Give the fresh divisions a few gentle years to settle before they bloom their fullest, and simply let them be while they do.
Myths
Peony buds need ants before they will open.
You can relax about the ants, because they simply come for the sweet nectar the buds offer, not to pry them open. The buds unfurl perfectly well on their own, and the ants cause no trouble at all while they sip. A peony blooms in its own good time, ants or no ants.