Rhododendron ‘Grace Seabrook’ (Seabrook 1965) (R. ‘Jean Marie de Montague’ x R. strigillosum) – This is the rhododendron that people go shopping for as soon as they see it blooming in nearby gardens. The bright blood red flowers are borne in spherical trusses (starting late March) and contrast well against the deep green foliage. Grows 4-5′ high by 4-6′ wide. Zone 6.
Rhododendron ‘Ruby Hart’ (Whitney 1956) ([R. ‘Carmen’ x R. ‘Elizabeth’}) x R. elliottii) – The tubular deep red blooms (1.5″ across) of ‘Ruby Hart’ have an unusual silky sheen, like they are almost made of wax. These appear from March to April over glossy dark green foliage. ‘Ruby Hart’ has a compact growth habit. Grows 2′ high by 2′ wide. Hardy to zone 6.
Rhododendron ‘Vulcan’s Flame’ (Lancaster 1958) (R. griersonianum x R. ‘Mars’) – This cultivar is very similar to ‘Vulcan’ (it is a reverse cross) with bright red flowers (May to June) that are slightly translucent and fire-up with the morning sun. These are nicely contrasted by the deep green foliage (sun tolerant). Grows 5′ high by 5-6′ wide. Hardy to zone 5.
Rhododendron ‘Baden-Baden’ (Hobbie 1956) (R. ‘Essex Scarlet’ x R. forrestii ssp. forrestii Repens Group) – An easy rhododendron for novice gardeners with clear red flowers (darker red centers) from April to May. This old-time favourite also features deep green leaves that are slightly twisted. Tolerates full sun with even soil moisture. Grows 2′ high by 2′ wide. Hardy to zone 6.
Rhododendron ‘Elizabeth Ostbo Red’ (Ostbo 1958) (sport or hybrid of R. ‘Elizabeth’) (syn. ‘Ostbo’s Elizabeth’, ‘Elizabeth Red Foliage’) – The new growth of this cultivar is an attractive burgundy red, that fades as the leaves mature. The blood red funnel-shaped flowers are borne in April, with a light repeat bloom in September. Grows 3′ high by 4′ wide. Zone 6.