Peonies: Care and Growing Guide

The one thing that kills more peonies than anything else

The single most common reason peonies fail to bloom is planting the eyes — the pink buds at the top of the fleshy root — too deep. In Zones 3–6, eyes should be exactly 1–2 inches below the soil surface. In Zones 7–8, plant at 1 inch or shallower.

This is not a minor detail. A peony planted 3–4 inches deep will grow healthy foliage every year and produce zero flowers. Gardeners often wait five or six years before discovering the problem. After fifty-plus years of peony breeding research, the American Peony Society lists planting depth as the primary cultural failure across all regions of the US.

The fix is simple: if your peonies won’t bloom and you have ruled out shade, dig one up in fall and check the eye depth. Replant at 1.5 inches and you will likely see flowers the following spring.

Types of peonies for American gardens

Three major types grow in US gardens, and they differ in bloom time, maintenance, and zone tolerance.

Herbaceous peonies are the familiar garden variety. They die to the ground each fall and re-emerge in spring. They are the easiest to plant, the most widely available, and the best choice for most US gardeners in Zones 3–8.

Tree peonies are woody shrubs that keep their stems through winter. They bloom 2–3 weeks earlier than herbaceous types and are hardier in warm zones because they need fewer chill hours. The flowers are enormous — some reach 10–12 inches across.

Itoh peonies (intersectional hybrids) cross herbaceous and tree peonies. They have the large flowers and extended zone range of tree peonies with the die-back habit of herbaceous types. They are more expensive ($30–60 per plant) but bloom longer than either parent and resist botrytis better.

Zone and sun requirements

Peonies thrive in USDA Zones 3–8. They need winter cold to set flower buds, specifically 500–600 hours below 40°F. This rules out Zone 9 and warmer for most herbaceous varieties.

For zone-specific guidance on your location, see Planting Zones: A US Guide which covers the full USDA zone map with state-by-state detail.

Zone 3–4: All herbaceous peonies perform well. Apply 4 inches of mulch after the ground freezes to protect shallow-planted eyes from frost heave.

Zone 5–6: The ideal range. Full selection available. In Zone 6, apply light mulch (2 inches) in November as a precaution in the first year.

Zone 7–8: Plant eyes at only 1 inch below the surface. Extended warm falls can delay dormancy and reduce chill hour accumulation. Choose early-blooming cultivars to beat summer heat.

Zone 9 and warmer: Standard herbaceous peonies fail. Itoh peonies sometimes survive in Zone 9 with supplemental chilling. Tree peonies are the most zone-9-tolerant option.

Sun requirements: Peonies need at least 6 hours of direct sun daily for good bloom production. Less than 4 hours means sparse or no flowers. Morning sun with afternoon shade (in warm zones) is acceptable. Full sun produces the most flowers and sturdier stems.

How to plant peonies step by step

Plant bare-root divisions in fall (September–November in most zones). Container-grown plants can go in spring or fall, but fall-planted peonies establish faster.

1. Choose the right site. Select a spot with at least 6 hours of sun. Avoid planting under or near trees — roots compete for water and the canopy blocks sun. Give each plant 3 feet of space in every direction.

2. Prepare the soil. Dig a hole 18 inches wide and 18 inches deep. Mix 4 inches of finished compost into the removed soil. Good drainage is critical — peonies rot in waterlogged soil. If your soil holds water, raise the planting area 4–6 inches above grade.

3. Set the root. Place the root in the hole with eyes facing up. The top of the eyes should be 1–2 inches below the final soil surface. In Zone 7–8, aim for 1 inch. Do not go deeper than 2 inches anywhere in the continental US.

4. Backfill and firm. Fill the hole with amended soil. Firm gently to remove air pockets. Do not tamp heavily — you want some soil structure.

5. Water in. Water deeply immediately after planting. Apply 2 inches of mulch around the plant, keeping mulch 2 inches away from the stem base.

6. Mark the spot. Peonies go dormant completely in winter. Mark the location with a stake or label so you do not accidentally dig through the crown.

How to start composting walks through making finished compost, the best amendment for peony bed preparation.

First year through third year: what to expect

Year one: Minimal or no flowers. Foliage grows and the root system expands. This is normal. Water once a week in dry weather.

Year two: Modest bloom — typically 2–5 flowers per plant. The plant begins to look like a proper peony. Stem strength improves over the previous year.

Year three and beyond: Full bloom. A mature peony in good conditions produces 30–50 flowers per plant in peak years. Stem strength also peaks, and the plants need little attention beyond staking very double-flowered types.

The first three years are the hardest to get through because the lack of flowers feels like failure. It is not. Almost every peony planted correctly will bloom well by year three.

Seasonal care

Spring: Remove winter mulch gradually as shoots emerge. Do not rush — a late frost on bare shoots can damage tender growth. Fertilize once with a low-nitrogen fertilizer (such as 5-10-10) when shoots are 3–4 inches tall. Never fertilize with high-nitrogen products, which push lush foliage at the expense of flowers.

Before bloom: Install supports for double-flowered varieties (‘Festiva Maxima’, ‘Sarah Bernhardt’, ‘Kansas’) before they reach 12 inches tall. The peony ring — a circular wire support on stakes — is the most practical option. Trying to stake after rain-weighted flowers have already bent is difficult.

After bloom: Deadhead spent flowers immediately. Cut the stem back to the first leaf below the flower. Do not remove leaves — they feed the root system through summer and fall. Healthy foliage until frost means more flower buds for next year.

Fall: After the first hard frost, cut all stems to about 2 inches above ground. Remove and discard cut stems — do not compost them, as they can harbor botrytis spores. Apply 2–3 inches of mulch around (not on top of) the crowns.

Why ants visit peonies

Ants crawl over peony buds in late spring and cause genuine alarm for new growers. The explanation is simple: peony buds produce a sugary nectar on the bud scales that ants harvest. The relationship is neutral — the ants get food and the peonies get nothing from it, but they lose nothing either.

The old myth that ants are necessary for peony buds to open is completely false. Remove ants from a bud and it opens normally. Spray ants with insecticide and the flowers open anyway.

Ants become a problem only if you bring cut peonies inside. Shake the stems vigorously over the garden before bringing flowers in.

Common problems in US peony gardens

Botrytis blight: The most serious peony disease in humid climates. Stems wilt at the base, buds turn brown before opening, and gray fuzzy mold appears on affected tissue. Caused by Botrytis cinerea fungus in wet spring conditions.

Prevention: Space plants at 36 inches for air circulation. Avoid overhead watering. Remove and discard all fallen debris in fall — do not compost it.

Treatment: Cut affected stems well below the diseased tissue. Drench the soil surface with a copper fungicide when symptoms appear.

Failure to bloom: Check in order — (1) eye depth, (2) shade, (3) plant age, (4) zone compatibility. Most non-blooming peonies are planted too deep.

No flowers but healthy foliage: Classic sign of too-deep planting. Dig and replant at 1–2 inches in fall.

Stem flop: Heavy double flowers on thin stems fall over after rain. Install supports before bloom, or choose single and semi-double flowered varieties that are more self-supporting.

Best peony varieties for US gardens

These cultivars are widely available at US garden centers and perform well across multiple regions.

Pairing peonies in the spring garden

Peonies bloom for 2–3 weeks in late May and early June in most US zones. Before and after that window, the plant is foliage only — handsome foliage, but it needs companions to carry the visual interest.

Before peonies open: plant alliums, siberian iris, and salvia at the front. These bloom simultaneously with early peonies and extend the display.

After peonies finish: taller summer perennials such as coneflower and black-eyed Susan fill the backdrop while peony foliage remains as a clean dark green mass.

Peonies pair well with other sun-loving spring bloomers in a mixed border. See full sun perennials for a complete list of summer and fall companions that bridge the gap after peony season ends.

The pollinators that visit peonies — primarily bumblebees — also benefit from having a continuous succession of flowers through the season. Attract pollinators to your garden covers plants that extend the nectar and pollen season from spring through fall.

For the broader spring garden picture, best spring perennials covers early-season companion plants that bloom alongside and before peonies.