Umbrella Magnolia Umbrella Tree
Magnolia tripetala
Magnoliaceae · broadleaf deciduous tree · native
Last updated
Data Coverage 4 of 6 dimensions
Quick Facts
Height
30 ft
Growth Rate
Moderate
Light
Part Shade
Soil
Moist
Water
Moderate
Hardiness
Zone Zones 6a–8b
Bloom Time
May
Origin
southern Pennsylvania to northern Georgia and Alabama to Kentucky and Arkansas
Phenological Calendar
As of April 9, 2026, Puget Sound stations range from 1181.7 to 1312.1 GDD₃₂. Umbrella Magnolia Umbrella Tree typically reaches bloom start at 1368 GDD₃₂, predicted around Apr 17.
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 | Bloom start | 56 |
| Seattle / UW | 1,289 | Pre-season | Bloom start | 79 |
| Kent / Auburn | 1,246 | Pre-season | Bloom start | 122 |
| Olympia / Tumwater | 1,227 | Pre-season | Bloom start | 141 |
| Bellingham / Whatcom | 1,213 | Pre-season | Bloom start | 155 |
| Tacoma / Puyallup | 1,198 | Pre-season | Bloom start | 170 |
| Sequim / Rain Shadow | 1,182 | Pre-season | Bloom start | 186 |
| Stage | GDD32 | Typical Window |
|---|---|---|
| ○ Bloom start BBCH 61 NEXT | 1368 | Mar 15-May 15 est. Apr 17 (forecast) |
| Full bloom BBCH 65 | 1824 | — est. May 10 (avg) |
| Bud break BBCH 07 | — | Feb 15-Mar 15 |
| Leaf emergence BBCH 11 | — | Mar 1-Apr 1 |
| Bloom end / petal fall BBCH 69 | — | Apr 15-May 31 |
| Fruit/seed development BBCH 71 | — | Jun 1-Aug 31 |
| Leaf drop BBCH 93 | — | Oct 15-Nov 30 |
| Dormancy BBCH 97 | — | Nov 15-Feb 28 |
Range: 917–1105 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 Apr 9, 2026. Predicted dates use 16-day weather forecast through Apr 25, 2026, then climate normals.