Birch

The Birch is the second most common of Britain’s broad-leaved trees There are two native species in the UK - Silver Birch (Betula Pendula) and Downy Birch (Betula Pubescens) - which often hybridise. Mature trees can reach 30m in height, forming a light canopy with elegant, drooping branches.

This beautiful and elegant tree has inspired artists and writers, past and present. It is now mainly planted for its aesthetic value and as a nursery tree to protect young forestry plantations. It is an opportunist species which will quickly colonise bare ground.

Identification

Bark and Leaves
Birches are easily recognised by their white, papery bark. The white bark sheds layers like tissue paper and becomes black and rugged at the base. As the trees mature, the bark develops dark, diamond-shaped fissures. Twigs are smooth and have small dark warts.

Light green leaves are small and ovate with a toothed edge, which fade to yellow in autumn.

The Silver Birch can be distinguished from the similar Downy Birch by its more triangular leaves, with jagged teeth, growing from hairless leaf stalks. It also has droopier branches and leaves.

Downy Birch is a more upright, less 'weeping', tree than Silver Birch and the bark is more brown in colour with more obvious horizontal grooves. Its leaves are more rounded and grow on hairy stalks, hence the name 'Downy'.

Flowers and seeds
Birch is monoecious, meaning both male and female flowers (catkins) are found on the same tree, from April to May.
Male catkins are long and yellow-brown in colour, and hang in groups of two to four at the tips of shoots, like lambs' tails. Female catkins are smaller, short, bright green and erect. After successful pollination (by wind), female catkins thicken and change colour to a dark crimson. Masses of tiny seeds are borne in autumn, which are dispersed by wind.

Height and Age
It grows as quite a tall tree, up to 30m, for up to 100 years. Sometimes it will grow small like a shrub but always with elegant, drooping branches, a light canopy and whip like twigs.
The Silver Birch was one of the first trees to recolonise the UK after the last glacial period.

Where to find it
Birch is found on heathland, moorland and mountainsides, as well as on dry, sandy soils.
The Silver Birch grows well all over Britain although Downy Birch is more common in Scotland.
Downy birch is found on damper soils than silver birch, and can even tolerate waterlogged or peaty conditions. Its range is more northerly and western than silver birch, and it can grow at higher elevations.

Woodland Ecology
Birch woods (which may include downy or silver birch, or both) have a light, open canopy, providing the perfect conditions for grasses, mosses, wood anemone, bluebells, wood sorrel and violets to grow. They can be used to improve soil quality for other plants to grow. Its deep roots bring otherwise inaccessible nutrients into the tree, which are recycled on to the soil surface when the tree sheds its leaves.

They provide food and habitat for more than 300 insect species - the leaves attract aphids, providing food for ladybirds and other species further up the food chain, and are also a food plant for the caterpillars of many moths. Birch trees are particularly associated with specific fungi including fly agaric, woolley milk cap, birch milk cap, birch brittlegill, birch knight, chanterelle and the birch polypore (razor strop).
Woodpeckers and other hole-nesting birds often nest in the trunk, while the seeds are eaten by siskins, greenfinches and redpolls.