Peonies are the grandest flower of late spring: huge, blowsy blooms in pink, white, red and coral, often scented, on a plant that can live for fifty years or more in the same spot. A mature peony in full flower is one of the great sights of the garden, and the plant asks for almost nothing in return except patience.
Patience is the key word, because peonies hate being moved and can take two or three years to settle in and flower properly after planting. They also need winter cold to flower well, so they are at their best in Zones 3–7. Plant them once, plant them at the right depth, and then leave them alone — a peony left undisturbed will outlive the gardener who planted it.
Peonies at a glance
| Growing factor | What peonies need |
|---|---|
| Sun | full sun |
| Soil pH | 6.0–7.0 |
| Days to germination | 14–28 |
| Days to maturity | 365–730 |
| Spacing | 36–48 inches apart |
| Water needs | moderate |
| Cold tolerance | hardy |
| Family | Paeoniaceae |
Starting seeds
Peonies give you a choice: start seeds indoors for earlier flowers, or sow direct once the soil warms. For the earliest display, sow indoors a few weeks before your last frost — late winter in Zones 3–5, early spring in Zones 6–8, late winter in Zones 9–10 — and transplant out after the frosts end. For direct sowing, wait until the soil is workable and warming: late spring in Zones 3–5, mid-spring in Zones 6–8, early spring in Zones 9–10. Zones 11–13 are frost-free, so both methods work through much of the year; check your local extension service for the best local dates. Seeds germinate in 14–28 days. Keep seed mix or soil evenly moist until seedlings are up, and give indoor seedlings as much light as you can. Our seed starting calculator plans your indoor sowing date, and the germination time calculator estimates when to expect seedlings.
Transplanting and planting out
Transplant seedlings out after the last frost, on a cloudy day or in the evening so they do not wilt in the sun. Space plants 36–48 inches apart — that spacing is what keeps air moving and disease down — and water each plant in well. Our plant spacing calculator works out exactly how many plants fit your bed, and the square foot garden planner helps lay them out.
Soil and feeding
Peonies grow best in fertile, well-drained soil with a pH of 6.0–7.0. Dig in compost before planting — it feeds the soil and helps it hold moisture without getting soggy — and mulch after planting to keep the roots cool and the weeds down. Feed during the growing season with a balanced fertiliser at the label rate, roughly once a month while plants are actively growing, and stop feeding as the season ends. Our fertiliser calculator works out the right amount for your bed, and the compost ratio calculator helps you make good compost to dig in.
Watering
Peonies have moderate water needs: keep the soil evenly moist while plants are establishing and flowering, and water deeply rather than little and often so the roots grow down. Water at the base in the morning so the foliage dries during the day, mulch to hold moisture in, and watch for wilting in hot, dry spells. Our watering calculator gives a starting point for your bed size, and the watering schedule generator can build a routine around it.
Sunlight and temperature
Peonies need full sun — at least six hours of direct sun a day. Peonies are hardy and tolerate frost and cold weather well, so they can be planted out earlier and left in the ground over winter in most zones. In frost-free Zones 11–13, heat and a lack of winter chill can limit performance, so give them the coolest spot you have. Check your zone with the hardiness zone finder before choosing varieties. Our sunlight calculator can check whether your spot gets enough sun.
Pests and diseases
The pests and diseases to watch for on peonies are aphids, slugs, cutworms. Peonies are remarkably trouble-free. Aphids may cluster on buds in spring, and slugs can nibble young shoots, but the main problem is usually fungal botrytis in wet springs, helped by good air flow and clean autumn clear-up. Check plants weekly, looking under leaves as well as on top, and act early. Hand-pick larger pests, knock aphids off with a strong spray of water, and remove badly affected leaves. Keep the area weed-free and avoid wetting the foliage when you water, since damp leaves invite fungal disease. Our pest identifier helper can help identify what you are seeing, and the plant disease checker helps narrow down leaf and stem problems.
Companion plants
Good companions for peonies are lavender, marigolds, garlic, chives. Lavender, marigolds, garlic and chives are good companions, and low perennials around the base help keep the soil cool without competing with the peony's roots. Our companion planting finder can suggest more pairings for your bed plan.
Harvesting
Cut peonies for the vase when the buds feel soft like a marshmallow and are just starting to open — a bud cut at the marshmallow stage will open fully in water and last a week. Cut in the morning, strip the lower leaves, and put stems straight into water. Deadhead spent flowers after blooming to keep the plant tidy, but leave the foliage all summer: it feeds the roots for next year's flowers. Cut the foliage down in autumn once it dies back. Our harvest date calculator can estimate your picking date from your sowing date, and the vegetable yield estimator helps you work out how much a bed will produce.
Common problems and fixes
| Problem | Likely cause | Fix |
|---|---|---|
| No flowers | planted too deep, or plant too young | Replant at the correct depth with the eyes just below the surface. |
| Buds rot before opening | botrytis in wet weather | Improve air flow and remove affected buds promptly. |
| Stems flop under the flowers | heavy blooms on weak stems | Support plants early with a peony ring or stakes. |
No flowers
The most common reason a peony never flowers is planting depth: the pink buds (eyes) on the crown must sit no more than a couple of inches below the soil surface. A peony planted too deep grows leaves and no flowers for years. Lift it in autumn and replant it shallowly, and be patient — it may take another year to flower.
Buds rot before opening
In a wet spring, peony buds can turn brown and rot before they open. This is botrytis, a fungal disease that thrives in damp, still air. Remove affected buds, space plants well, and clear away dead foliage in autumn so the fungus has nowhere to overwinter.
Stems flop under the flowers
A peony in full flower is heavy, and rain makes it heavier, so stems flop and flowers end up in the mud. Put a peony ring or stakes in place in early spring, before the stems grow through them — supports added after the plant has flopped never look right.
Frequently asked questions
How long does it take to grow peonies?
From planting to maturity takes 365–730 days — about 1–2 years (365–730 days from planting). Seed germination takes 14–28 days, and the total time depends on whether you start from seed, a nursery plant, or a bulb or cutting.
How far apart should I plant peonies?
Space peonies 36–48 inches apart. That spacing gives each plant room for air movement, which keeps disease down, and room to reach its full size without crowding its neighbours.
What soil pH do peonies need?
Peonies prefer a soil pH of 6.0–7.0. Test your soil before amending it — most garden soils are close enough, and guessing with lime or sulphur can do more harm than good.
How long do peonies take to flower?
A newly planted peony often takes two to three years to settle in and flower properly, and the data puts maturity at 365–730 days. Do not move a peony that is slow to flower — moving it resets the clock.
Can peonies be moved?
They can, but they hate it. If you must move one, do it in autumn, dig up as much of the root as you can, replant at the same shallow depth, and expect it to take a year or two to flower again.