Rhododendron luteum Nabucco

Rhododendron Nabucco is perhaps the best Chinese Azalea among the red-flowered cultivars, as its abundant, late spring flowers are a vibrant, almost pure red that does not fade in the sun. This shrub has sumptuous clusters of trumpet-shaped flowers in a brilliant red, highlighted by a velvety reverse that has surprising black and mauve highlights. They bloom with a light fragrance, on glossy, green foliage tinged with purple, taking on beautiful autumnal hues. Unlike Japanese Azaleas, this plant is deciduous and very hardy. Too little known and too little used, deciduous azaleas are infinitely graceful plants, with many different qualities; they should be planted in the garden or in a large pot on the terrace as quickly as possible!

Azaleas are actually Rhododendrons, whose flowers have 5 stamens instead of 10. They are plants of the Ericaceous family, just like heathers, mainly preferring lime-free, slightly acidic soils and humid climates. The Nabucco Azalea, still little known in commerce, is one of many hybrids derived from the Rhododendron luteum, a robust and extremely hardy Eurasian botanical species. It is classified in the Knap-Hill horticultural group of Azaleas.

'Nabucco' is a fairly slow-growing shrub. It has a rather spreading, bushy habit, both slender and dense. By the age of 10, this Azalea will be about 1.25 m (4 ft 1 in) in height and 1 m (3 ft 4 in) in spread. It can eventually reach up to 1.40 m (4 ft 7 in)  by 1.20 m (3 ft 11 in) under ideal growing conditions. Its lightly fragrant flowers bloom over a long period in early to late June (depending on the climate) on young, glossy green leaves tinged with bronze, then purple. The flowers, 6 to 7.5 cm (2.4 to 3 in) in diameter, are a flared, funnel-shape, clustered at the ends of the branches. The buds, tinged with red and black, open into satiny, vermillion-red corollas. They are adorned with 5 long, red, arched stamens that contribute to the beauty of the flowers. The deciduous foliage is composed of simple, oval-lanceolate leaves with smooth edges, arranged alternately on the branches. They vary from 5 to 10 cm (2 to 3.9 inches) in length, and their dark green, summer colour turns to reddish-orange-purple in October. Azaleas and Rhododendrons have a shallow root system that always needs to be kept moist, but they also dislike waterlogged soil which would suffocate the roots.

Chinese Azaleas have fewer requirements than evergreen Japanese azaleas: they are very hardy, tolerate sunny positions better, and even occasionally dry soil depending on the hybrids. Nevertheless, they are at their best in cool climates, with distinct winters, planted in humus-rich, fertile, lime-free soil. They are very beautiful shrubs for borders, with a very attractive, natural habit, blooming twice a year. They are a perfect accompaniment to Japanese maples, which also change their appearance with the seasons, as well as Japanese camellias or their graceful, often fragrant, autumn flowering cousins, the C.sasanqua hybrids.  'Nabucco' will be magnificent when combined with other Chinese Azaleas in shades of white, orange, peach or red. The undeniable beauty of deciduous Azaleas merits the changes needed to create the conditions they love. They can also be grown in a large, carefully chosen pot with suitable compost, and watered with non-alkaline water.