Rhubarb
Rheum rhabarbarum
· perennial · introduced
Last updated
Data Coverage 3 of 6 dimensions
Phenological Calendar
As of April 9, 2026, Puget Sound stations range from 1181.7 to 1312.1 GDD₃₂. Rhubarb typically reaches 'flower buds visible' at 1428 GDD₃₂, predicted around Apr 21.
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 | Pre-season | 'Flower buds visible' | 116 |
| Seattle / UW | 1,289 | Pre-season | 'Flower buds visible' | 139 |
| Kent / Auburn | 1,246 | Pre-season | 'Flower buds visible' | 182 |
| Olympia / Tumwater | 1,227 | Pre-season | 'Flower buds visible' | 201 |
| Bellingham / Whatcom | 1,213 | Pre-season | 'Flower buds visible' | 215 |
| Tacoma / Puyallup | 1,198 | Pre-season | 'Flower buds visible' | 230 |
| Sequim / Rain Shadow | 1,182 | Pre-season | 'Flower buds visible' | 246 |
| Stage | GDD32 | Typical Window |
|---|---|---|
| ○ 'Flower buds visible' BBCH '51' NEXT | 1428 | '' est. Apr 21 (forecast) |
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.