Birches
Few trees can equal the all-year pleasure granted to us by the Silver Birch. The typical trunk climbs straight to the growing tip. The light branches support cascading bunches of thin twigs which during the leafless months of winter are like the loose hair of this lady of the woods. A near relative is the Downy birch which lacks the same grace and charm. Both species have given rise to many sports and cultivars which, when added to the numerous birches imported from other parts of the northern hemisphere, cause confusion and much pondering and debate when identifications are sought. The problem is amplified by all birches being described, in common parlance, as “silver”.
If we move away from town streets, formal parks and other public spaces where trees are planted for purely decorative purposes, we can more easily distinguish between our two common and easily grown species. Actually, both grow themselves very easily. Their seeds are wind borne and can travel long distances. My own picture-book silver birch grew as a sapling in a garden drive miles from here before being transplanted. The Silver birch much prefers light, sandy or gravelly soil while the Downy birch is happier in river valleys and other moist soils.
Twigs and leaves are always important diagnostic features. Silver birch twigs are slightly rough while those of the Downy are covered with soft, silky hairs. Silver birch leaves are very spiky round the edges and narrow to a tapering point. The leaf base forms straight lines either side of the main rib. The leaf of the other species is conspicuously rounder and smoother.
Those birch specimens imported from all parts of the northern hemisphere for decorative purposes in public, more formal places, provide many variations on the basic theme and can make any walk in the park more interesting and sometimes quite puzzling.
