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The rhododendron genus contains around 800 species including both evergreen and deciduous shrubs and trees.

Spring flowering rhododendron. Westonbirt ArboretumAzaleas were once considered a separate genus but have now been incorporated into rhododendron. Thanks to plant collectors such as Sir Joseph Hooker, George Forrest, Ernest Wilson and Joseph Rock, many of these now grow in Britain.

The Holfords of Westonbirt were not just interested in rhododendron species but were also keen to participate in the early 20th century fashion for selecting and growing new and unusual hybrids. Many of these can be seen around Savill Glade and Main Drive.

Rhododendron Basilicum

Introduced from West Yunnan and Upper Burma by George Forrest in 1912, this rare shrub grows best in woodland conditions. Flowers are pale yellow sometimes with a tinge of crimson and with a deep crimson basal blotch.

Rhododendron WilliamsianumRhododendron williamsianum

A dome-shaped evergreen with distinctive heart-shaped leaves and pretty bell shaped flowers in April. The species was introduced from China by E. Wilson in 1908 and is named after the sponsor of his expedition, JC Williams of Caerhays Castle in Cornwall. A large spreading clump can be seen on the edge of Main Drive near Duke’s Cut Gate.

Rhododendron Quinquefolium

An exquisitely beautiful and rare deciduous azalea introduced from Japan in 1896. Flowers are pure white with green spots appearing after the leaves in April-May. New collections of this species were made during a recent trip to Japan by Westonbirt staff.

Rhododendron 'Mrs R. S. Holford'

This rare hybrid is named after the wife of Westonbirt Arboretum’s creator Robert Stayner Holford. Its funnel-shaped salmon-coloured flowers are patterned inside with crimson spots.

Rhododendron griersonianum

This lovely species has a number of notable features: brilliant scarlet bell-shaped flowers in June, distinctive long tapered flower-buds and woolly pale brown undersides to the leaves. It was introduced to Europe in 1917 from China and N. Burma by Geroge Forrest.

Rhododendron Augustinii at Westonbirt Arboretum credit Jane GiffordRhododendron Augustinii

This large shrub has funnel-shaped flowers in April and May. They vary in colour from pale to deep lavender blue. It was named after botanist Augustine Henry who first found it in Hubei, China in 1899.

Last updated: 10th July 2017


Westonbirt Arboretum

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England's Woods and Forests are cared for by Forest Enterprise England, an agency of the Forestry Commission.