Solidarity Rhododendron

Rhododendron 'Solidarity'

Ericaceae · broadleaf evergreen shrub · introduced

Last updated

A dense, well-shaped evergreen shrub reaching 4 feet in 10 years and 5 to 6 feet at maturity. Openly funnel-shaped flowers with wavy edges, 3 inches wide, purplish-red margins shading to light purplish-pink in the throat with purplish-red dorsal spotting, carried in dome-shaped trusses of 12 to 13 flowers. Midseason bloom. A hybrid of 'The Honourable Jean Marie de Montague' crossed with R. degronianum subsp. yakushimanum, bred by Schannen (ARS #912).

A hardier, more compact version of Jean Marie de Montague's coloration on a yakushimanum-derived plant form. The color gradient from purplish-red margins to light pink throat produces a multi-tone truss effect. Sparse light tan indumentum adds textural interest to the foliage underside. Hardy to -15°F (Zone 5b-9a). Part shade to full sun on acidic, well-drained soil (pH 4.5-6.0). Compact enough to fit more landscape positions than Jean Marie itself. Twenty-one diseases and 15 pests documented at the genus level. All parts contain grayanotoxins and are toxic if ingested.

Quick Facts

Height
4 ft in 10 years; reaches 5-6 ft at maturity
Spread
4-5 ft
Growth Rate
Moderate
Light
Part Shade to Sun
Soil
Well Drained
Water
Moderate
Hardiness
Zone Zones 5b–9a
Bloom Time
Apr 20-May 5
Origin
Hybrid: 'The Honourable Jean Marie de Montague' ×
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 20-May 5
Full bloom BBCH 65 Apr 28-May 12
Bloom end BBCH 69 May 8-May 25
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.