Leatherleaf Viburnum
end of floweringViburnum rhytidophyllum
Adoxaceae, Caprifoliaceae · broadleaf evergreen shrub · introduced
Last updated
Plant Profile
Size & Form
Height
10–15 ft
Growth Rate
Medium
Site Requirements
Light
Part Shade
Soil Drainage
Well Drained
Water
Moderate
Hardiness
Zones 5a–8b
Ornamental Interest
Bloom Time
May to June
Origin
central and western China
Field Observations
Leatherleaf Viburnum: End of flowering
Watch for this season
Powdery MildewHigh
Active Conidial Spread
Larval Hatching & Feeding
Root weevilModerate
Adult Emergence & Foliar Feeding
Diseases: Regionally Documented (7)
Pests: Regionally Documented (3)
Phenological Calendar
As of June 3, 2026, Puget Sound stations range from 2435.5 to 2672.8 GDD₃₂. Leatherleaf Viburnum has passed end of flowering (2398 GDD₃₂).
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of Jun 3, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 2,673 | end of flowering | — | — |
| Kent / Auburn | 2,665 | end of flowering | — | — |
| Seattle / UW | 2,610 | end of flowering | — | — |
| Olympia / Tumwater | 2,570 | end of flowering | — | — |
| Tacoma / Puyallup | 2,535 | end of flowering | — | — |
| Bellingham / Whatcom | 2,533 | end of flowering | — | — |
| Sequim / Rain Shadow | 2,436 | end of flowering | — | — |
View full calendar (1 stages)
| Stage | GDD32 | Typical Window |
|---|---|---|
| ● end of flowering BBCH 69 NOW | 2398 Observed | — |
Source: Field observation, SeaTac, WA (Highline SeaTac Botanical Garden). About GDD₃₂ →
Season tracker for Kent / Auburn as of Jun 3, 2026. Predicted dates use 16-day weather forecast through Jun 19, 2026, then climate normals.
Data Maturity Structured Multiple sources. Expert review underway.