Kindly sponsored by
Peter Norris, enabling the use of The Rhododendron Handbook 1998
Article from Bean's Trees and Shrubs Hardy in the British Isles
'Rhododendron occidentale' from the website Trees and Shrubs Online (treesandshrubsonline.
Deciduous shrub or small tree, to 8(–10) m; young twigs glabrous to densely covered with gland-tipped and/or eglandular hairs. Leaves (2.5–)3.5–8.2(–10.8) × (0.8)1.2–2.9(–3.6) cm, ovate to obovate or elliptic, lower surface usually covered with unicellular and gland-tipped multicellular hairs. Flower bud scales with outer surface covered with unicellular and eglandular or gland-tipped multicellular hairs, margin ciliate with gland-tipped or eglandular hairs. Pedicels covered with hairs that are usually gland-tipped. Flowers with a sweet fragrance, appearing with the leaves or after they have expanded; calyx 1–4(–9) mm; corolla white and pink to salmon or pink, with an orange blotch on the upper corolla lobe, funnelform, with tube gradually expanding into the limb, 30–60 mm. Capsule sparsely covered with eglandular or gland-tipped hairs. Flowering June-July. Royal Horticultural Society (1997)
Distribution United States Oregon & California
Habitat s.l.-2,700 m
RHS Hardiness Rating H6
Awards AM 1944 (Royal Botanic Gardens, Kew); flowers white, heavily flushed rose pink, with a yellow blotch. AGM 1993
Conservation status Least concern (LC)
Taxonomic note R. occidentale may be distinguished from the allied R. austrinum and R. luteum by the colour of the corolla. Royal Horticultural Society (1997)
A deciduous, rounded bush 8 ft or more high; young shoots slightly downy. Leaves oval or obovate, 2 to 4 in. long, 3⁄4 to 11⁄2 in. wide, tapering at the base, often rounded at the apex; upper surface glossy green and furnished with scattered hairs, lower surface pale, rather glaucous, downy (at least when young); stalk downy, 1⁄4 in. or less long. Flowers fragrant, white with a blotch of yellow on the upper side, 21⁄2 to 3 in. across, produced in terminal clusters of six to twelve after the leaves, during June and July. Calyx-lobes up to 3⁄16 in. long, ciliate. Corolla-tube 1 in. or more long, downy; stamens and style protruded, 2 to 21⁄2 in. long. Bot. Mag., t. 5005. (s. Azalea ss. Luteum)
Native of western N. America; introduced by Wm Lobb for Messrs Veitch about 1851. This beautiful azalea is the only species of its section found west of the Rocky Mountains. It has many points of resemblance to, and appears to be the Western representative of, R. arborescens, but has larger yellow-blotched flowers and its foliage is quite hairy beneath; the calyx also is shorter. It does not blossom until the great azalea season is over, or until it is itself in almost full leaf. It is one of the best summer-flowering shrubs, although it has taken horticulturists a long time to find that out. In 1857, Lindley, then the high priest of gardening, pronounced it to be ‘of little value’. Anthony Waterer of Knap Hill and Koster of Boskoop, by crossing it with the bright-coloured azaleas that flower earlier, laid the foundation of a beautiful race of late-flowering varieties. See further in the section on hybrids, p. 914.