History and design
The Azalea Garden was transformed into its current layout in 1995. Designed to show the development of deciduous azalea hybrids, 29 beds in two concentric circles now exhibit specimens produced from the 1820s to the present day. The selected plants are good examples of hardy azaleas that can be used in large and small gardens. The Azalea Garden is best visited in late springtime, when the bushes are ablaze with colour.
The 12 hybrid groups start with the Ghent hybrids, which were created by a Belgian baker in the 1820s from a series of crosses between azaleas from eastern North America. As early as 1850, there were over 500 different, named Ghent hybrids.
Next up are the Mollis hybrids, derived from Rhododendron japonicum and other Asian species. The first selection of Mollis hybrids were made by Louis van Houtte of Belgium, working with plants grown from seed collected in Japan in 1861.
Later specimens include the Knap Hill hybrids, designed to improve the Ghent hybrids, and double-flowered Rustica Flore Pleno hybrids introduced in around 1890.
Plant collector Ernest Wilson introduced 51 azaleas from Japan to America in the early 20th century. After seeing, in Kurume, the 250-century-old named azaleas from which he made his selection, he wrote: 'I gasped with astonishment when I realised that garden-lovers of America and Europe knew virtually nothing of this wealth of beauty'.