Japanese Pieris
Pieris japonica
Ericaceae · broadleaf evergreen shrub · introduced
Last updated
This profile synthesizes data from multiple published sources. Expert field review is in progress.
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.
Quick Facts
Phenological Calendar
As of April 23, 2026, Puget Sound stations range from 1434.4 to 1592.7 GDD₃₂. Japanese Pieris has passed 'full bloom' (798 GDD₃₂).
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of Apr 23, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 1,593 | 'Full bloom' | — | — |
| Seattle / UW | 1,554 | 'Full bloom' | — | — |
| Kent / Auburn | 1,537 | 'Full bloom' | — | — |
| Olympia / Tumwater | 1,505 | 'Full bloom' | — | — |
| Bellingham / Whatcom | 1,483 | 'Full bloom' | — | — |
| Tacoma / Puyallup | 1,472 | 'Full bloom' | — | — |
| Sequim / Rain Shadow | 1,434 | 'Full bloom' | — | — |
| Stage | GDD32 | Typical Window |
|---|---|---|
| 'First bloom' BBCH '61' | 580 | '' |
| ● 'Full bloom' BBCH '65' NOW | 798 | '' |
| 'Late bloom / mature flowers' BBCH '67' | — | '' |
| Leaf emergence BBCH 11 | — | — |
| Leaf expansion BBCH 12 | — | — |
GDD = Growing Degree Days (base 32°F, Jan 1 start). Why base 32? Hover over GDD values for source details. Season tracker for Kent / Auburn as of Apr 23, 2026. Predicted dates use 16-day weather forecast through May 9, 2026, then climate normals.