Types of peonies: tree, herbaceous, intersectional explained

Types of peonies: tree, herbaceous, intersectional explained

If "peony" makes you picture one massive double pink flower, you are missing two-thirds of the genus. The botanical group Paeonia covers three radically different growth habits — soft-stemmed herbaceous perennials that die to the ground, woody tree peonies that build a permanent shrub framework, and the intersectional Itoh hybrids that combine the best of both. This guide covers all three types with bloom timing, flower forms, named cultivars, and the pet-safety warning every owner of a dog, cat, or horse needs. The headline: the ASPCA confirms all peonies are toxic to dogs, cats, and horses — the toxic principle is paeonol, present in stems and roots, causing vomiting, diarrhea, and depression.

Match a peony to your bed: Photograph your border in Growli and we measure light hours, soil pH cues, and existing companion plants — then rank the peony types most likely to bloom for you.

How the 3 types are organised

The American Peony Society and the Peony Society (Belgium) split the genus into three botanical and horticultural groups:

1. Herbaceous peonies (Paeonia lactiflora, P. officinalis, and hybrids) — soft stems that die to the ground each autumn. New shoots emerge from the crown each spring. Live 50+ years once established.
2. Tree peonies (Paeonia suffruticosa, P. delavayi, P. rockii, and hybrids) — woody shrubs that keep their stems all year. Slower to establish but eventually reach 4 to 7 feet tall.
3. Intersectional / Itoh peonies — crosses between herbaceous and tree peonies, first achieved by Dr. Toichi Itoh of Japan in 1948 (first germinated flowers 1964). They have tree-peony foliage and flower size with herbaceous dieback — the best of both parents.

A second filter is flower form, applied across all three types per the American Peony Society:

• Single — one row of broad petals around a central boss of yellow stamens.
• Semi-double — multiple rows of petals with stamens still visible.
• Double — packed petals that completely conceal stamens, often called "bomb" or "rose" form depending on petal arrangement.
• Anemone — outer ring of broad petals plus a central mass of narrow petaloids (modified stamens) in a contrasting colour.
• Bomb — outer ring of broad guard petals plus a tightly packed dome of inner petals like a pompom.

Type 1 — Herbaceous peonies

Herbaceous peonies are the perennials most gardeners picture first. They die to the ground each autumn, push new red-tinged shoots from the crown in early spring, and bloom for two to three weeks in late spring to early summer. Once established, a healthy clump can live 50 to 100 years with minimal care.

Herbaceous peony cultivars

1. Sarah Bernhardt — Paeonia lactiflora 'Sarah Bernhardt'

The most-planted herbaceous peony in the world. Massive double rose-pink fragrant flowers on 32-inch stems, blooming mid to late season. Introduced in 1906 and still the benchmark for double pink peonies. Strong stems but heavy flower heads benefit from peony rings.

Form: Double. Colour: Rose-pink. Bloom: Mid to late (May to June). Height: 32 inches.

2. Karl Rosenfield — Paeonia lactiflora 'Karl Rosenfield'

The classic crimson herbaceous peony. Large double deep red flowers on 30-inch stems, mid-season bloomer. Introduced in 1908. Reliable performer in USDA zones 3 to 8.

Form: Double. Colour: Deep red. Bloom: Mid (late May to early June). Height: 30 inches.

3. Bowl of Beauty — Paeonia lactiflora 'Bowl of Beauty'

The most-planted anemone-form herbaceous peony. Outer ring of broad rose-pink guard petals around a centre of pale yellow petaloids. Introduced in 1949. Long-stemmed, excellent cut flower.

Form: Anemone. Colour: Pink with yellow centre. Bloom: Mid (late May to early June). Height: 32 inches.

4. Festiva Maxima — Paeonia lactiflora 'Festiva Maxima'

The classic white-with-crimson-flecks heritage peony. Massive double white flowers with characteristic crimson splashes on inner petals. Introduced in 1851 — the longest-lived peony cultivar in the trade. Intensely fragrant.

Form: Double. Colour: White with crimson flecks. Bloom: Early to mid (late May). Height: 34 inches.

5. Coral Charm — Paeonia 'Coral Charm'

A semi-double herbaceous hybrid in striking coral-peach that fades to ivory as flowers age. Bred by Sam Wissing in 1964. Earlier blooming than P. lactiflora cultivars. American Peony Society Gold Medal 1986.

Form: Semi-double. Colour: Coral to ivory. Bloom: Early (mid-May). Height: 36 inches.

6. Krinkled White — Paeonia lactiflora 'Krinkled White'

The classic single-form herbaceous peony. One row of crinkled white petals around a brilliant boss of yellow stamens. Introduced in 1928. Less needs of staking than double cultivars because the lighter flowers don't bend stems.

Form: Single. Colour: Pure white with yellow stamens. Bloom: Mid (late May to early June). Height: 32 inches.

Type 2 — Tree peonies

Tree peonies are woody deciduous shrubs that build a permanent framework of branches over many years. They are not actually trees — they are shrubs typically 4 to 6 feet tall at maturity. The flowers are larger than herbaceous peonies (up to 10 inches across) and the foliage has a finer, more dissected look.

Tree peonies are slow to establish — expect three to five years before significant flowering — but live 100+ years once mature. They bloom about two weeks earlier than herbaceous peonies, opening in mid to late May in most zones.

Tree peony cultivars

7. High Noon — Paeonia 'High Noon'

Bred by A.P. Saunders in 1952. Semi-double bright yellow flowers with red flares at the base of each petal. Tall, vigorous, and one of the easiest yellow tree peonies for cool climates. Reaches 5 to 6 feet tall.

Form: Semi-double. Colour: Yellow with red flares. Bloom: Late spring (May). Height: 5 to 6 feet.

8. Shimanishiki — Paeonia suffruticosa 'Shimanishiki'

A heritage Japanese tree peony famous for variable flower colour on a single plant — some blooms open pure red, others pure white, and many show pink-and-white striped or splashed petals. Sometimes called "Two-in-One" or "Striped Peony." Semi-double form.

Form: Semi-double. Colour: Red, white, or striped. Bloom: Late spring (May). Height: 4 to 5 feet.

9. Kamada Fuji — Paeonia suffruticosa 'Kamada Fuji'

Classic Japanese tree peony with double lavender-pink flowers up to 8 inches across, on a compact bush 4 to 5 feet tall. Strong fragrance. Reliable performer in zones 5 to 8.

Form: Double. Colour: Lavender-pink. Bloom: Late spring (May). Height: 4 to 5 feet.

Type 3 — Intersectional / Itoh peonies

Intersectional (Itoh) peonies are crosses between herbaceous and tree peonies, first hybridised by Dr. Toichi Itoh of Japan in 1948. The seeds did not germinate until after his death, and the first Itoh flowers opened in 1964. These hybrids combine the best traits of both parents:

• Tree-peony foliage and flower size — deeply dissected leaves, blooms up to 8 inches across.
• Herbaceous dieback habit — stems die to the ground each autumn, eliminating the slow establishment problem of tree peonies.
• Long bloom period — Itohs flower for 3 to 4 weeks (vs 1 to 2 weeks for most peonies) because they open multiple flowers per stem in sequence.
• Strong stems — no staking needed, unlike heavy double herbaceous peonies.

Itohs are the most expensive peony group — typical prices in 2026 are $40 to $80 per root division — because they are more difficult to propagate. But a single plant can produce 30 to 50 flowers in its third year onwards.

Intersectional cultivars

10. Bartzella — Paeonia 'Bartzella'

The benchmark yellow Itoh. Bred by Roger F. Anderson, registered in 1986. Very large bright yellow double blossoms (up to 8 inches across) with a slight red stain at the centre. Produces up to 50 or more huge flowers on sturdy short stems that do not require staking. Strong lemon fragrance. American Peony Society Gold Medal 2006.

Form: Double. Colour: Bright yellow with red centre stain. Bloom: Mid (May to June). Height: 30 to 36 inches.

11. Cora Louise — Paeonia 'Cora Louise'

Bred by Roger F. Anderson, registered in 1986. Semi-double white blooms up to 8 inches across with a dramatic burst of cranberry-pink at the centre and vibrant golden frills around the stamens. Light sweet fragrance. American Peony Society Award of Landscape Merit.

Form: Semi-double. Colour: White with cranberry-pink centre. Bloom: Mid (May to June). Height: 30 inches.

12. Julia Rose — Paeonia 'Julia Rose'

Bred by Roger F. Anderson, registered in 1991. Semi-double flowers that open coral-pink, age to cherry-red, then fade to yellow — three colours visible on a single plant as flowers age. American Peony Society Award of Landscape Merit.

Form: Semi-double. Colour: Coral-pink ageing to cherry-red and yellow. Bloom: Mid (May to June). Height: 30 inches.

PET SAFETY — peonies are toxic to dogs, cats, AND horses (ASPCA)

The ASPCA toxic plants database lists Paeonia spp. (peony) as toxic to dogs, cats, and horses. The toxic principle is paeonol, concentrated most heavily in the stems and roots. All three types — herbaceous, tree, and Itoh — contain paeonol, and no variety is safer than another.

Clinical signs after ingestion include vomiting, diarrhea, and depression. Peony poisoning is generally considered mild to moderate rather than life-threatening — peony ingestion is not usually fatal — but symptoms can be persistent enough to require veterinary support.

Dogs that chew peony stems and dig up peony roots are the most common emergency-vet calls in this category. Cats are at lower risk but can be affected if they chew cut flowers brought indoors. Horses occasionally chew herbaceous peonies in mixed pasture-and-ornamental plantings.

If a pet ingests any part of a peony, call your vet or the ASPCA Animal Poison Control Center at (888) 426-4435. Most cases involve mild GI signs that resolve in 24 to 48 hours, but call for guidance if symptoms persist or the dog is small.

If you have a dog that digs in beds, plant peonies in raised beds or behind low fencing for the first season — the disturbed soil around a freshly planted peony is the most attractive to digging dogs.

How to choose the right type of peony

Pick by space and lifespan.

• For a permanent, slow-growing focal shrub: tree peony. Site carefully because it will live 100+ years and resents transplanting.
• For a classic perennial border that returns reliably every year: herbaceous peony. The workhorse of the late-spring garden.
• For maximum flower power on a manageable plant: intersectional (Itoh) peony. Most flowers per plant of any peony type, no staking, long bloom season — but the most expensive.

Pick by climate.

• USDA zones 3 to 5: Herbaceous peonies are the safest choice. Tree peonies survive but bloom buds can freeze in late frosts. Itohs are hardy but expensive — protect the crown with mulch in zone 3.
• USDA zones 6 to 8: All three types thrive. UK gardens (most equivalent to zones 7 to 9) grow all three reliably.
• USDA zones 9+: Peonies struggle without sufficient winter chill (need 400 to 500 hours below 40°F to bloom). Choose Itohs or specific low-chill P. lactiflora cultivars and treat as an investment — don't expect heritage 100-year clumps.

Pick by flower form. Doubles and bombs are the showy "wedding flower" choices. Singles and semi-doubles have lighter heads, need no staking, and are favoured by pollinators because the stamens are accessible to bees.

Planting timing by USDA zone

Zones 3 to 6: Plant herbaceous and Itoh roots in early autumn (September to mid-October) before the ground freezes. Plant tree peonies the same window or in early spring as soon as soil can be worked. Bare-root divisions establish best in cool autumn soil.

Zones 7 to 8: Plant in mid-autumn (October to early November). Container plants can go in any time the soil isn't waterlogged or frozen.

Zone 9 and warmer: Plant in late autumn to early winter. Provide afternoon shade and protect from heat stress in summer.

Crucial planting depth: Plant herbaceous and Itoh peonies with the eyes (growing buds) just 1 to 2 inches below the soil surface — no deeper. Planting too deep is the single biggest reason peonies fail to bloom. A peony planted 4 inches deep may produce healthy foliage for decades without ever flowering.

Tree peonies are different — plant tree peonies with the graft union 4 to 6 inches BELOW the soil surface so the tree peony scion can put down its own roots above the host (which would otherwise sucker and overtake).

Common care across the category

Site in full sun with 6+ hours of direct light for best bloom. Peonies tolerate part shade but produce far fewer flowers.

Plant in deep rich soil — peonies are heavy feeders. Mix in plenty of compost and well-rotted manure at planting. Once established, top-dress with compost in autumn.

Don't move them. Peonies resent being divided or transplanted. A well-sited herbaceous or tree peony can live for 50 to 100 years without ever needing to move. Only divide when absolutely necessary (every 15+ years if clumps decline), and do it in early autumn.

Stake double cultivars early. Heavy double herbaceous peonies ('Sarah Bernhardt', 'Karl Rosenfield', 'Festiva Maxima') flop after rain. Install peony rings in early spring while shoots are short — once stems are 18 inches tall it's too late.

Cut foliage to the ground after first frost for herbaceous and Itoh peonies. This removes overwintering disease spores (botrytis, peony leaf blotch). Compost the trimmed foliage. Tree peonies need no autumn cleanup — leave the woody framework in place.

Don't blame the ants. Ants on peony buds are eating sugary nectar — they do nothing for the bud and they cause no harm. The folk belief that ants are needed to open the buds is false.

Try Growli: Snap a photo of any peony with Growli — instant ID, type confirmation, and care plan in 60 seconds.

Related articles

• Types of flowers — 20+ annuals and perennials — the broader category
• Types of hydrangeas — 6 species + pruning — the other big late-spring shrub
• Types of roses — 12 varieties for every garden style — the other classic perennial flowering shrub
• Types of tulips — 12 classic and rare varieties — the spring bulb that precedes peonies
• Pet-safe houseplants — 20 non-toxic plants — indoor alternatives for pet households
• Companion planting guide — what to plant with peonies

Reviewed and updated by the Growli editorial team. For questions about anything here, open Growli and ask — or email hello@getgrowli.app.