Persian Lilac
Syringa persica
Oleaceae · broadleaf deciduous shrub · introduced
Last updated
Quick Facts
Height
4–8 ft
Growth Rate
Medium
Light
Full Sun to Part Shade
Soil
Well Drained
Water
Moderate
Hardiness
Zones 5a–8b
Fall Color
Insignificant
Phenological Calendar
As of May 24, 2026, Puget Sound stations range from 2172.5 to 2394 GDD₃₂. Persian Lilac has passed 'full bloom' (1364 GDD₃₂).
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of May 24, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 2,394 | 'Full bloom' | — | — |
| Kent / Auburn | 2,373 | 'Full bloom' | — | — |
| Seattle / UW | 2,332 | 'Full bloom' | — | — |
| Olympia / Tumwater | 2,295 | 'Full bloom' | — | — |
| Tacoma / Puyallup | 2,259 | 'Full bloom' | — | — |
| Bellingham / Whatcom | 2,256 | 'Full bloom' | — | — |
| Sequim / Rain Shadow | 2,173 | 'Full bloom' | — | — |
View full calendar (2 stages)
| Stage | GDD32 | Typical Window |
|---|---|---|
| 'First bloom' BBCH '61' | 1080 | '' |
| ● 'Full bloom' BBCH '65' NOW | 1364 | '' |
Source: 'Master catalog (OSU), GDD50 base' About GDD₃₂ →
Season tracker for Kent / Auburn as of May 24, 2026. Predicted dates use 16-day weather forecast through Jun 9, 2026, then climate normals.
Data Maturity Baseline Extension data. Expert review underway.