Southern Catalpa
Catalpa bignonioides
Bignoniaceae · broadleaf deciduous tree · native
Last updated
Quick Facts
Height
30–40 ft
Spread
20-40 ft
Growth Rate
Fast
Light
Sun to Part Shade
Soil
Well Drained
Water
Low
Hardiness
Zone Zones 5a–8b
Bloom Time
May to June
Origin
Georgia, Florida, Alabama, and Mississippi
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. Southern Catalpa typically reaches 'first bloom' at 2878 GDD₃₂, predicted around Jun 13.
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' | 757 |
| Kent / Auburn | 2,113 | Pre-season | 'First bloom' | 765 |
| Seattle / UW | 2,085 | Pre-season | 'First bloom' | 793 |
| Olympia / Tumwater | 2,047 | Pre-season | 'First bloom' | 831 |
| Tacoma / Puyallup | 2,016 | Pre-season | 'First bloom' | 862 |
| Bellingham / Whatcom | 1,994 | Pre-season | 'First bloom' | 884 |
| Sequim / Rain Shadow | 1,926 | Pre-season | 'First bloom' | 952 |
| Stage | GDD32 | Typical Window |
|---|---|---|
| ○ 'First bloom' BBCH '61' NEXT | 2878 | '' est. Jun 13 (avg) |
| 'Full bloom' BBCH '65' | 3248 | '' est. Jun 26 (avg) |
Range: 2365–2748 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.