Japanese Pieris

‘Leaf emergence’

Pieris japonica

Ericaceae · broadleaf evergreen shrub · introduced

Last updated

Pieris japonica (Ericaceae) is a broadleaf evergreen shrub native to Japan. It grows to about 12 feet tall with a dense, layered habit. Drooping chains of small, urn-shaped, fragrant white to pink flowers appear in early spring from buds formed the previous fall. New growth emerges in shades of red, bronze, or copper before maturing to glossy dark green.

Japanese pieris requires acidic, moist, well-drained soil in part shade. It is susceptible to lace bug, which causes stippled, bleached foliage, and to Phytophthora root rot in poorly drained sites. Many cultivars are available offering variations in flower color (white to deep pink), new growth color, and mature size. It blooms on old wood and should be pruned after flowering. All parts are toxic (andromedotoxin). Hardy in Zones 7a to 8b.

Japanese pieris is well suited to the Puget Sound lowlands. It thrives in the acidic soils common here without amendment and performs well in the partial shade typical of established landscapes. Phytophthora root rot is the primary disease concern, particularly on sites with heavy clay and poor drainage. Andromeda lace bug (Stephanitis takeyai) is the most significant pest; plants in full sun are more susceptible. Black vine weevil is also a persistent problem, with characteristic leaf-margin notching from adult feeding and larval root damage that can kill plants. Phytophthora ramorum (sudden oak death) has been found in WA nurseries on Pieris but is not yet widespread in landscapes. Site in morning sun with afternoon shade in well-drained, acidic soil amended with organic matter for best performance.

Plant Profile

Size & Form

Height
9-12 ft
Spread
6-8 ft
Growth Rate
Slow
Size at 20 yr
8 ft
Lifespan
Moderate

Site Requirements

Light
Sun to Part Shade
Soil Drainage
Well Drained
Soil pH
4.2–5.5
Water
Moderate
Drought Tolerance
Low
Hardiness
Zones 4b–8b

Ornamental Interest

Bloom Time
March-April
Fall Color
Evergreen; no significant fall color change. new spring growth is bronze-green to reddish.
Origin
East Asia

Field Observations

Japanese Pieris new leaves
Japanese Pieris: New leaves
April 23, 2026 · Issaquah
Japanese Pieris new leaves
Japanese Pieris: New leaves
April 20, 2026 · Lake Wilderness Arboretum
Japanese Pieris mature flowers / late bloom
Japanese Pieris: Mature flowers / late bloom
April 9, 2026 · Issaquah
Japanese Pieris full bloom
Japanese Pieris: Full bloom
March 20, 2026 · Issaquah
Watch for this season
Leaf and Flower GallHigh

Gall Development & Sporulation

Andromeda Lace BugHigh

First Generation Nymph Emergence

Black vine weevilHigh

Adult Emergence

Azalea bark scaleModerate

Spring Egg Laying

+ 1 more — see full disease and pest lists below

Diseases: Regionally Documented (4)

Pests: Regionally Documented (4)

Phenological Calendar

As of June 3, 2026, Puget Sound stations range from 2435.5 to 2672.8 GDD₃₂. Japanese Pieris has passed ‘leaf emergence’ (1509 GDD₃₂).

Regional Season Tracker

GDD₃₂ accumulation across 7 Puget Sound stations · as of Jun 3, 2026
Station GDD₃₂ Current Stage Next To Go
Issaquah / East King 2,673 ‘Leaf emergence’ — —
Kent / Auburn 2,665 ‘Leaf emergence’ — —
Seattle / UW 2,610 ‘Leaf emergence’ — —
Olympia / Tumwater 2,570 ‘Leaf emergence’ — —
Tacoma / Puyallup 2,535 ‘Leaf emergence’ — —
Bellingham / Whatcom 2,533 ‘Leaf emergence’ — —
Sequim / Rain Shadow 2,436 ‘Leaf emergence’ — —
View full calendar (7 stages)
Stage GDD32 Typical Window
‘Flower bud swell’ BBCH ‘55’ — ‘Jan 15-Feb 15’
‘First bloom’ BBCH ‘61’ 484 ‘Feb 20-Mar 10’
‘Full bloom’ BBCH ‘65’ 630 Observed ‘Mar 5-Mar 20’
‘Late bloom / mature flowers’ BBCH ‘67’ — Observed ‘Mar 20-Apr 15’
● ‘Leaf emergence’ BBCH ‘11’ NOW 1509 Observed ‘Apr 10-Apr 25’
‘Leaf expansion’ BBCH ‘12’ — Observed ‘Apr 20-May 10’
‘Flower bud set (next year)’ BBCH ‘55’ — ‘Jul-Aug’
Regional estimate
Range: 340–542 GDD₃₂ (6yr)

Sources: ‘OSU Herms calendar (129 GDD50), 6-year Kent calibration median 630 GDD32 (range 550-706, stdev 59.4). Field observation, Issaquah, WA’ ; ‘Field observation, Lake Wilderness Arboretum, 2026-04-20’ About GDD₃₂ →

Season tracker for Kent / Auburn as of Jun 3, 2026. Predicted dates use 16-day weather forecast through Jun 19, 2026, then climate normals.

Cultivars (14)
'Brouwer's Beauty'
Hybrid (P. japonica x P. floribunda). Wide, upright habit. White flowers are sterile, produce no seed pods.
Cary Award winner ('Distinctive Plants for New England'). Hardy.
'Cavatine'
Selection of P. j. var. yakushimanum. Compact, low-growing mound. White flowers.
Hardy to USDA Zone 5
'Christmas Cheer'
Early blooming. Pink flowers with darker pink corolla tip, creating two-tone effect.
'Dorothy Wycoff'
Red flower buds opening to pale pink to white.
'Flaming Silver'
Variegated. Young leaves bright red, margins turn pink then silver-white. White flowers. Slow growing, to 5 ft tall in 10 years.
Hardy to USDA Zone 5
'Forest Flame'
New leaves brilliant red, turning pink then white then green. White flowers.
'Little Heath'
Compact. Bronze-red new growth develops yellowish green variegation when mature. May revert to green form, propagated as 'Little Heath Green'.
'Mountain Fire'
Vivid red new growth. White flowers.
'Prelude'
P. j. var. yakushimanum. Dwarf, 2 ft x 3 ft. New leaves pinkish, maturing dark green. Pink buds, white flowers.
Hardy to USDA Zone 5
'Purity'
Compact habit. Pure white flowers in dense panicles.
'Valley Fire'
Brilliant red new growth. Large white flowers.
'Valley Rose'
Pastel pink flowers. Deep green foliage.
Introduced by Bob Tichnor, Oregon State University
'Valley Valentine'
Maroon flower buds developing into deep rose-pink flowers. Glossy dark green foliage. 5-6 ft, dense, slow to average growth.
Introduced by Bob Tichnor, Oregon State University. Hardy to USDA Zone 5.
'Variegata'
Burnished red new growth, maturing to cream-edged foliage. White flowers. 3-5 ft, slower and denser than species.
Hardy to USDA Zone 5
Data Maturity
Structured Multiple sources. Expert review underway.