National Birch Collection - Bethlehem Wood
Did you know?
- The British Isles has three native birch species: the silver birch (Betula pendula), downy birch (Betula pubescens) and dwarf birch (Betula nana).
- Native North Americans traditionally used bark from the paper birch to make paper, baskets and canoes. The Economic Botany Collection at Kew Gardens contains a model canoe made from paper birch, which was donated in 1848.
- Birches are considered ‘pioneer species’, which means they are among the first plants to colonise freshly cleared soil. They can do this because they are very hardy, easily pollinated, distribute their seeds efficiently and tolerate inhospitable soils.
Bethlehem Wood, located a short walk west of the Main Entrance and Visitor Centre, is comprised almost entirely of birches. There are more than 340 hybrids, cultivars and species, and they represent the National Collection.
What is a National Collection?
Loss of variety within horticulture in the 1970s led to the foundation of the National Council for the Conservation of Plants and Gardens (NCCPG - now called Plant Heritage). The Council set out to conserve the rich garden flora of the British Isles by forming ‘national plant collections’. The idea is that each collection is as complete a representation of a genus or section of a genus as possible, incorporating both species and cultivars. Today, there are some 650 National Plant Collections representing around 350 genera. Wakehurst Place holds four National Collections.
There are more than 50 species of birch trees and shrubs growing in the world’s northern temperate and Arctic regions. They are noted for the colours exhibited by their bark, which range from white to apricot through cinnamon to dark cherry red and chocolate. The whiteness of the bark derives from the chemical betulin. Betulinic acid has been found to act against malaria, inflammation and HIV. Extracts from birch can be used to treat snakebites and provide insecticides. Birches are also economically important for their timber, which is used to make furniture, flooring and plywood.
Things to look out for
Wakehurst’s birches are subdivided into Asian, European and American continental zones that demonstrate the genus’s vast geographic range. Specimens range from Britain’s common white-trunked silver birch (Betula pendula) to a sleek red-brown-trunked Betula albo-sinensis from west China. There is also one of North America’s rarest trees, the Virginia round-leafed birch (Betula uber). This species was once thought to be extinct; cultivating the tree at Wakehurst is helping to contribute to its survival. In early spring, the ground beneath the trees is coloured yellow with primroses; this gives way to blue as bluebells come into bloom during May.