Northern Catalpa
Catalpa speciosa
Bignoniaceae · broadleaf deciduous tree · native
Last updated
Quick Facts
Height
40–60 ft
Spread
8-16 ft
Growth Rate
Fast
Light
Full Sun
Soil
Well Drained
Water
Low
Hardiness
Zone Zones 4a–8b
Bloom Time
May to June
Fall Color
Yellow, insignificant
Origin
Illinois and Indiana to western Tennessee and northern
Watch for this season
Root Colonization Period
Phenological Calendar
As of May 14, 2026, Puget Sound stations range from 1926.1 to 2121.1 GDD₃₂. Northern Catalpa typically reaches 'first bloom' at 2336 GDD₃₂, predicted around May 24.
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of May 14, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 2,121 | Pre-season | 'First bloom' | 215 |
| Kent / Auburn | 2,113 | Pre-season | 'First bloom' | 223 |
| Seattle / UW | 2,085 | Pre-season | 'First bloom' | 251 |
| Olympia / Tumwater | 2,047 | Pre-season | 'First bloom' | 289 |
| Tacoma / Puyallup | 2,016 | Pre-season | 'First bloom' | 320 |
| Bellingham / Whatcom | 1,994 | Pre-season | 'First bloom' | 342 |
| Sequim / Rain Shadow | 1,926 | Pre-season | 'First bloom' | 410 |
| Stage | GDD32 | Typical Window |
|---|---|---|
| ○ 'First bloom' BBCH '61' NEXT | 2336 | '' est. May 24 (forecast) |
| 'Full bloom' BBCH '65' | 2735 | '' est. Jun 8 (avg) |
Range: 1890–2189 GDD₃₂
(6yr)
Source: 'Master catalog (OSU), converted GDD50->GDD32 via Kent bloom-date mapping' About GDD₃₂ →
Season tracker for Kent / Auburn as of May 14, 2026. Predicted dates use 16-day weather forecast through May 30, 2026, then climate normals.
Diseases: Regionally Documented (1)
Data Maturity Baseline Extension data. Expert review underway.