The Westwood Valley, a steep ravine running from the Water Gardens to Westwood Lake, is home to Wakehurst's collecton of Asian plants.
Did you know?
- In winter and early spring, plantings of Daphne bholua bloom in Westwood Valley displaying delicate, highly scented flowers.
- According to WWF, 242 new plant species were discovered in the eastern Himalayas between 1998 and 2008. Among the new finds is an ultramarine blue flower, the colour of which changes according to the temperature.
Plants from this region of the world have long fascinated gardeners, because the choicest species of many genera grow there. They are often those with the showiest flowers, most vibrant autumn colours or nicest bark. The temperate parts of Asia, especially the eastern Himalayas, have the highest diversity of plants, with more than 10,000 species. The UK, by contrast, has just 1,400 native species.
The wide diversity of temperate woody plants in eastern Asia came about because the region escaped the advance of glaciers during the last ice age. Within this ‘refugium’ plants were able to adapt to the wide range of prevailing environmental conditions, from tundra and tropics, to arid mountains and lush valleys. Eastern Asia was also one of the first centres for the evolution of the first flowering plants and conifers. Species growing today, such as gingko and dawn redwood, appear in fossils there dating back more than a million years.
Things to look out for
Westwood Valley’s cool and moist conditions enable many Asian species to thrive in the Sussex Weald. The valley represents the landscape of the eastern Himalayas below the tree-line, with semi-evergreen forests of rhododendrons, laurels, maples, alders, oaks, birches, rowan and conifers. Among the tree specimens are the small-leaved rowan (Sorbus microphylla), with attractive white berries, and the Bhutan pine (Pinus wallichiana). Wakehurst’s staff are expanding the Valley’s rhododendron collection to show how these plants vary across Asia. Growing alongside the exotics are natives of the Weald, including bluebells, lady’s smock and the common spotted orchid.