Chinese Lilac Rouen Lilac
Syringa chinensis
Oleaceae · broadleaf deciduous shrub · introduced
Last updated
Data Coverage 5 of 6 dimensions
Quick Facts
Height
8–15 ft
Light
Full Sun to Part Shade
Hardiness
Zone Zones 3a–8b
Phenological Calendar
As of April 9, 2026, Puget Sound stations range from 1181.7 to 1312.1 GDD₃₂. Chinese Lilac Rouen Lilac has passed 'first bloom' (1182 GDD₃₂).
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of Apr 9, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 1,312 | 'First bloom' | — | — |
| Seattle / UW | 1,289 | 'First bloom' | — | — |
| Kent / Auburn | 1,246 | 'First bloom' | — | — |
| Olympia / Tumwater | 1,227 | 'First bloom' | — | — |
| Bellingham / Whatcom | 1,213 | 'First bloom' | — | — |
| Tacoma / Puyallup | 1,198 | 'First bloom' | — | — |
| Sequim / Rain Shadow | 1,182 | 'Bud break' | 'First bloom' | 0 |
| Stage | GDD32 | Typical Window |
|---|---|---|
| 'Bud break' BBCH '07' | 511 | '' |
| ● 'First bloom' BBCH '61' NOW | 1182 | '' |
GDD = Growing Degree Days (base 32°F, Jan 1 start). Why base 32? GDD₃₂ thresholds from USA National Phenology Network citizen science observations (WA+OR). Season tracker for Kent / Auburn as of Apr 9, 2026. Predicted dates use 16-day weather forecast through Apr 25, 2026, then climate normals.
Diseases (8)
Podosphaera aphanis var. aphanis Powdery Mildew Pseudomonas syringae pv. syringae Bacterial Blight Botrytis cinerea Gray Mold abiotic (drought, heat stress) or bacterial (Xylella fast... Leaf Scorch Symptom category — not a single disease Leaf Spot Lilac ring Lilac Ring Mottle Phytophthora spp. (P Phytophthora Canker and Shoot Blight Symptom category — not a single disease Root Rot
Pests (5)
Cultivars (1)
'Lilac Sunday'
Common name: Lilac Sunday Lilac; Mature height: 12 ft
Hardy to USDA Zone 3