Seven Sons Flower
Heptacodium miconioides
Caprifoliaceae · broadleaf deciduous shrub · introduced
Last updated
Quick Facts
Height
15–25 ft
Spread
8-10 ft
Growth Rate
Medium
Light
Full Sun to Shade
Soil
Well Drained To Moist
Water
Moderate
Hardiness
Zones 4–5
Bloom Time
September
Origin
central and eastern China, but apparently it is rather rare
Phenological Calendar
As of May 24, 2026, Puget Sound stations range from 2172.5 to 2394 GDD₃₂. Seven Sons Flower typically reaches 'first bloom' at 4870 GDD₃₂, predicted around Aug 13.
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 | Pre-season | 'First bloom' | 2,476 |
| Kent / Auburn | 2,373 | Pre-season | 'First bloom' | 2,497 |
| Seattle / UW | 2,332 | Pre-season | 'First bloom' | 2,538 |
| Olympia / Tumwater | 2,295 | Pre-season | 'First bloom' | 2,575 |
| Tacoma / Puyallup | 2,259 | Pre-season | 'First bloom' | 2,611 |
| Bellingham / Whatcom | 2,256 | Pre-season | 'First bloom' | 2,615 |
| Sequim / Rain Shadow | 2,173 | Pre-season | 'First bloom' | 2,698 |
View full calendar (2 stages)
| Stage | GDD32 | Typical Window |
|---|---|---|
| ○ 'First bloom' BBCH '61' NEXT | 4870 | '' est. Aug 13 (avg) |
| 'Full bloom' BBCH '65' | 5450 | '' est. Aug 30 (avg) |
Range: 4528–4926 GDD₃₂
(6yr)
Source: 'Master catalog (UMD), converted GDD50->GDD32 via Kent bloom-date mapping' 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.