Rhododendron Cunninghams White

The Hybrid Rhododendron 'Cunningham's White' at first sight is a beautiful, vigorous and very healthy plant. This old Scottish variety, still widely planted in gardens and commonly used as a graft, has a dense growth and a particularly hardy temperament. The bush produces a mass of small white flowers with purple markings on the throat in spring, and often again at the end of summer. This Rhododendron tolerates sunny exposures better than many others if the soil remains moist, as well as poor and infertile soils, acidic, neutral or even slightly alkaline if well amended!

Rhododendrons are plants of the Ericaceae family, just like heathers, preferring soils devoid of limestone, with an acidic tendency, and humid climates. Resulting from a cross made by Georges Cunningham in 1830 between Rhododendron caucasicum and R. ponticum var. Alba, Rhododendron 'Cunningham's White' forms a dense bush, initially with an upright habit, taking on a more spreading, wider than tall aspect over the years. At maturity, it will reach about 1.5 metres (4 feet 11 inches) in height and 2 metres (6 feet 7 inches) in spread. Its growth is rather slow, generally reaching 1 metre (3 feet 4 inches) in height and 1.2 metres (3 feet 11 inches) in spread at the age of 10. Its evergreen leaves, of medium to dark green in colour, are elliptical in shape, 13cm (5.1in) long, and cover the plant well. They have a velvety underside. In May-June, depending on the climate, its remarkably abundant flowering overwhelms the bush: its beautiful white flowers, tinged with pink on the edges, with a throat strongly marked with purple-brown, open in 20cm (7.9in) corymbs. It is not uncommon for the bush to bloom again in September, albeit with less generosity. Nectar-rich, they are highly visited by pollinating insects.

Like all Caucasian rhododendrons, 'Cunningham's White' is hardy down to -15°C or even -20°C. Although they prefer a semi-shaded exposure, these hybrids of R.caucasicum, a true mountain plant, can tolerate the morning sun as long as it is not scorching and their base remains cool. "Cunningham's White", with its generous and bright flowering, will easily adorn a small shaded space in the garden, in the company of ferns, blue or variegated hostas, Pieris, heathers, Kalmias, Azaleas and Japanese Maples, or other rhododendrons from the same group to create superb patchworks of textures and colours in spring. Cultivation in containers requires regular watering with non-alkaline water and specific fertilization for heath plants.