Chinese Fringetree
Chionanthus retusus
Oleaceae · broadleaf deciduous shrub · introduced
Last updated
Chinese fringetree is the Asian counterpart to white fringetree and it performs well in the Puget Sound lowlands for similar reasons: late bloom avoids frost, slow growth suits small lots, and the tree tolerates urban air pollution. It is slightly less cold-hardy than the American species (Zone 5a vs 4a) but that is irrelevant in our Zone 8b climate. The flowers emerge in May-June on new growth and are showier than C. virginicus. One oddity: the tree tends toward alternate-year flowering, so a spectacular bloom one year followed by a modest one is normal, not a sign of problems. Prefers deep, moist, acidic soil, which we naturally provide. Female plants produce blue fruit for birds. For a refined small specimen tree with virtually no disease problems, Chinese fringetree is one of the smartest choices available.
— Chris Welch, ISA Certified Arborist
Chinese fringetree (Chionanthus retusus, Oleaceae) is a deciduous shrub or small tree from China, Korea, and Japan, reaching 15 to 25 feet tall. White, fragrant flowers appear in terminal clusters in late spring, followed by blue ellipsoid fruit about 1.25 centimeters long. Glossy dark green leaves and a potentially multi-stemmed form add ornamental interest across seasons.
Chinese fringetree grows in full sun or partial shade (full sun for most profuse flowering) on well-drained soils, tolerating alkaline conditions, hardy in Zones 5a to 8b. It attracts birds and is suited to rain garden applications. No significant pest or disease issues are documented. The cultivar 'Arnold' is in the trade.
Quick Facts
Phenological Calendar
As of April 19, 2026, Puget Sound stations range from 1342.9 to 1500.8 GDD₃₂. Chinese Fringetree typically reaches 'full bloom' at 1932 GDD₃₂, predicted around May 9.
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of Apr 19, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 1,501 | Pre-season | 'Full bloom' | 431 |
| Seattle / UW | 1,465 | Pre-season | 'Full bloom' | 467 |
| Kent / Auburn | 1,441 | Pre-season | 'Full bloom' | 491 |
| Olympia / Tumwater | 1,415 | Pre-season | 'Full bloom' | 517 |
| Bellingham / Whatcom | 1,390 | Pre-season | 'Full bloom' | 542 |
| Tacoma / Puyallup | 1,381 | Pre-season | 'Full bloom' | 552 |
| Sequim / Rain Shadow | 1,343 | Pre-season | 'Full bloom' | 589 |
| Stage | GDD32 | Typical Window |
|---|---|---|
| ○ 'Full bloom' BBCH '65' NEXT | 1932 | '' est. May 9 (avg) |
GDD = Growing Degree Days (base 32°F, Jan 1 start). Why base 32? Source GDD₅₀ thresholds from Herms 2004 (OSU, Secrest Arboretum, Ohio) and UMD IPMnet (Gill & Klick, mid-Atlantic), converted to GDD₃₂ via Kent bloom-date mapping. Season tracker for Kent / Auburn as of Apr 19, 2026. Predicted dates use 16-day weather forecast through May 5, 2026, then climate normals.