Possumhaw Smooth Witherod Northern Wild Raisin

Viburnum nudum

Adoxaceae, Caprifoliaceae · broadleaf deciduous shrub · introduced

Last updated May 11, 2026

Plant Profile

Size & Form

Height

10 ft

Growth Rate

Medium

Site Requirements

Light

Full Sun to Part Shade

Soil Drainage

Well Drained

Water

Moderate

Hardiness

Zones 5a–8b

Ornamental Interest

Bloom Time

May to June

Fall Color

Red, scarlet

Origin

the Eastern Canada, and from New York south to Florida and

Powdery MildewHigh

Active Conidial Spread

Viburnum leaf beetleHigh

Larval Hatching & Feeding

Root weevilModerate

Adult Emergence & Foliar Feeding

Diseases: Regionally Documented (7)

Symptom category — not a single disease Leaf Spot Botrytis Shoot Blight Ramorum Blight (Sudden Oak Death) Multiple obligate biotrophic fungi (Erysiphales: Erysipha... Powdery Mildew Bacterial blight (Leaf spot) Symptom category — not a single disease Root Rot Botryosphaeria corticis Stem Canker

Pests: Regionally Documented (3)

Pyrrhalta viburni Viburnum leaf beetle Otiorhynchus spp. Root weevil Aphis fabae Bean aphid

Phenological Calendar

As of June 3, 2026, Puget Sound stations range from 2435.5 to 2672.8 GDD₃₂. Possumhaw Smooth Witherod Northern Wild Raisin typically reaches 'full bloom' at 3095 GDD₃₂, predicted around Jun 20.

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	Pre-season	'Full bloom'	422
Kent / Auburn	2,665	Pre-season	'Full bloom'	430
Seattle / UW	2,610	Pre-season	'Full bloom'	485
Olympia / Tumwater	2,570	Pre-season	'Full bloom'	526
Tacoma / Puyallup	2,535	Pre-season	'Full bloom'	560
Bellingham / Whatcom	2,533	Pre-season	'Full bloom'	562
Sequim / Rain Shadow	2,436	Pre-season	'Full bloom'	660

View full calendar (1 stages)

Stage	GDD₃₂	Typical Window	What to Look For
○ 'Full bloom' BBCH '65' NEXT	3095	'' est. Jun 20 (avg)	''

Regional estimate

Range: 2244–2602 GDD₃₂ (6yr)

Source: 'Master catalog (UMD), converted GDD50->GDD32 via Kent bloom-date mapping' 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.

Cultivars (1)

'Winterthur'

Common name: Winterthur Smooth Witherod; Mature height: 6 ft

Hardy to USDA Zone 5

Data Maturity

Structured Multiple sources. Expert review underway.