Seven Sons Flower
Heptacodium miconioides
Caprifoliaceae · broadleaf deciduous shrub · introduced
Last updated
Data Coverage 3 of 6 dimensions
Quick Facts
Height
15–25 ft
Light
Full Sun to Shade
Hardiness
Zone Zones 4–5
Bloom Time
September
Origin
central and eastern China, but apparently it is rather rare
Phenological Calendar
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of Mar 22, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Seattle / UW | 1,013 | Pre-season | Beginning of flowering | 6,743 |
| Issaquah / East King | 1,006 | Pre-season | Beginning of flowering | 6,750 |
| Olympia / Tumwater | 952 | Pre-season | Beginning of flowering | 6,804 |
| Bellingham / Whatcom | 948 | Pre-season | Beginning of flowering | 6,808 |
| Kent / Auburn | 942 | Pre-season | Beginning of flowering | 6,814 |
| Sequim / Rain Shadow | 924 | Pre-season | Beginning of flowering | 6,832 |
| Tacoma / Puyallup | 921 | Pre-season | Beginning of flowering | 6,835 |
| Stage | GDD32 | Typical Window |
|---|---|---|
| ○ Beginning of flowering BBCH 61 NEXT | 7756 | — |
Range: 4528–4926 GDD₃₂
(6yr)
GDD = Growing Degree Days (base 32°F, Jan 1 start). Why base 32? Source GDD₅₀ thresholds from Herms 2004 (OSU, Secrest Arboretum, Ohio) and UMD IPMnet (Gill & Klick, mid-Atlantic), converted to GDD₃₂ via Kent bloom-date mapping. Season tracker for Kent / Auburn as of Mar 22, 2026. Predicted dates use 16-day weather forecast through Apr 7, 2026, then climate normals.