Japanese Snowbell
Near 'Full bloom'Styrax japonicus
Styracaceae · broadleaf deciduous tree · introduced
Last updated
Japanese snowbell is a deciduous tree native to Japan, reaching 20-30 feet tall with a pyramidal form and smooth gray bark. The tree produces white, slightly fragrant bell-shaped flowers hanging from branch undersides in early summer and opposite, ovate leaves with fine fall color.
Japanese snowbell thrives in partial shade to full sun with well-drained, slightly acidic to neutral soil and moderate moisture. Hardy to zones 5-8, it is slow to medium in growth. The distinctive downward-facing flowers are a major ornamental asset, and the plant is excellent for specimen plantings. It requires consistent moisture and does not tolerate drought.
Quick Facts
Field Observations
Phenological Calendar
As of May 15, 2026, Puget Sound stations range from 1942.5 to 2137.2 GDD₃₂. Japanese Snowbell has reached 'first bloom' (1932 GDD₃₂) and is approaching 'full bloom', predicted around May 23.
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of May 15, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 2,137 | 'First bloom' | 'Full bloom' | 199 |
| Kent / Auburn | 2,130 | 'First bloom' | 'Full bloom' | 206 |
| Seattle / UW | 2,102 | 'First bloom' | 'Full bloom' | 234 |
| Olympia / Tumwater | 2,064 | 'First bloom' | 'Full bloom' | 272 |
| Tacoma / Puyallup | 2,033 | 'First bloom' | 'Full bloom' | 304 |
| Bellingham / Whatcom | 2,012 | 'First bloom' | 'Full bloom' | 324 |
| Sequim / Rain Shadow | 1,943 | 'First bloom' | 'Full bloom' | 394 |
| Stage | GDD32 | Typical Window |
|---|---|---|
| 'Leaf emergence' BBCH '11' | — | 'Early April' |
| 'Flower buds visible' BBCH '51' | — | 'Early-mid May' |
| ● 'First bloom' BBCH '61' NOW | 1932 | '' |
| ○ 'Full bloom' BBCH '65' NEXT | 2336 | '' est. May 23 (forecast) |
Source: 'Master catalog (UMD), converted GDD50->GDD32 via Kent bloom-date mapping' About GDD₃₂ →
Season tracker for Kent / Auburn as of May 15, 2026. Predicted dates use 16-day weather forecast through May 31, 2026, then climate normals.