Of all the birch characteristics, it is the bark that varies the most.
The bark is in a constant state of replacement, giving birches their characteristic peeling appearance.
Colours range from chalk white, yellow, pink and copper, to various shades of brown.
In their native environment, deciduous birches are pioneer trees, often the first to colonise open areas.
They are the hardiest of all the broad-leaved trees.
Adapted to living in fairly poor conditions, they can tolerate damp and dry soils, depending on species.
A good all-rounder, birch provides interest through the seasons:
Winter: Being deciduous, this tree reveals its beautiful bark in all its winter glory, such as the shaggy bark of B. luminifera, the smooth white peeling bark of B. jacquemontii and the coppery sheen of B. papyrifera var. commutata
Spring: With the emergence of drooping catkins and the first tender leaf shoots, birch looks good under-planted with spring bulbs.
Summer: Small oval, pointed and toothed leaves flutter on delicate-looking twigs, providing dappled shade.
Autumn: Birch provides gorgeous colour as the leaves turn a golden yellow.
Birches have had a plethora of uses through the ages, including:
Writing material: strips of peeling bark have been used since ancient times as a durable form of paper.
Beverage: wine, beer and juice have been and still are made from the sap; leaves have been used to make a diuretic tea.
Punishment: known as birching, twigs are bundled together and used to flog offenders; not used as often these days, however.
Transport: the bark was used to make lightweight, waterproof canoes by the indigenous people of North America.
Small stands of birch species can be seen in the Dunedin Northern Cemetery Arboretum and dotted around Dunedin Botanic Garden.
- Nicola Baines is a third-year apprentice at Dunedin Botanic Garden.
