Roseum Elegans Rhododendron

Rhododendron 'Roseum Elegans'

Ericaceae · broadleaf evergreen shrub · introduced

Last updated

A dense, spreading, vigorous evergreen shrub reaching 6 feet in 10 years and 10 to 12 feet at maturity. Funnel-shaped rosy lavender flowers with reddish-brown dorsal spotting, aging to pink, 2⅜ inches wide, carried in ball-shaped trusses of about 20 blooms. Late-midseason flowering. A catawbiense hybrid bred by Anthony Waterer at Knap Hill Nursery, UK (RHS 58).

One of the most climate-adaptable elepidote hybrids: cold hardiness to -25°F (Zone 4b-8a) combined with notable heat tolerance. A Waterer "ironclad" cultivar with vigorous growth, very long lifespan, and broad exposure tolerance. Mature specimens commonly exceed 10 feet and persist for decades. Full sun to part shade on acidic, well-drained soil (pH 4.5-6.0). Moderate-fast growth rate. Not a foundation choice; requires substantial space. Twenty-one diseases and 15 pests documented at the genus level. All parts contain grayanotoxins and are toxic if ingested.

Quick Facts

Height
6 ft in 10 years; reaches 10-12 ft at maturity
Spread
6-8 ft
Growth Rate
Moderate-fast
Light
Sun to Part Shade
Soil
Well Drained
Water
Moderate
Hardiness
Zone Zones 4b–8a
Bloom Time
Apr 25-May 15
Origin
Hybrid: Rhododendron catawbiense hybrid. Bred by A.
Watch for this season

Root Colonization (Spring–Fall)

Infection at Bud Break

Apothecia Formation & Spore Release

RustHigh

Aecial Stage (Alternate Host)

+ 13 more — see full disease and pest lists below

Phenological Calendar

Stage Typical Window
Bud swell BBCH 01-03 Mar 15-Apr 15
Bloom start BBCH 61 Apr 25-May 15
Full bloom BBCH 65 May 1-May 20
Bloom end BBCH 69 May 15-Jun 5
Bud set BBCH 55-59 Jul 15-Sep 15

Diseases: Regionally Documented (21)

Pests: Regionally Documented (15)

Data Maturity
Baseline Extension data. Expert review underway.