Most birch trees are known for their white bark.
Birches are trees of the genus Betula, native to the northern hemisphere. There are about 40 species of birch trees worldwide, most of which are found in lowlands such as river valleys. These trees have a variety of economic uses, ranging from cabinetmaking materials to food ingredients, and birches are also used in landscaping in some regions of the world.
All birch trees look more or less the same, and the main physical difference between birch trees is the color of their bark and their growth habits. The tallest trees can reach heights of 70 feet (21 meters), and some species known as “weeping birch” have long branches that bend downward with age. Birch leaves are simple and toothed, and the bark is very flaky and papery. Some well-known birch species include: red birch, white birch, silver birch, black birch, and yellow birch, all named for the color of their bark.
Birch bark is so similar to paper that some cultures have used it to make paper. Raw birch bark can be easily and gently removed from trees without damaging them and can be used to make paper, and the bark and wood can also be pulped to make paper. Most birch also have a very strong, lightweight wood with a fine grain that is attractive to people in the construction industry, and birch is particularly prized for instruments and loudspeakers thanks to its resonance.
These trees are deciduous, lose their trees in winter, and prefer slightly acidic, clayey soils near riverbanks. Birch trees can thrive in environments where other plants struggle to survive and tend to take over if given free rein. As long as the trees get enough sunlight and water, they will develop into strong, healthy specimens.
Historically, birch bark has been used in teas and tisanes, and the birth sap can be made into a type of beer. Oil extracted from birch trees can be used to condition a wide variety of woods, along with leather, and fermented birch leaves were once used to condition sailing equipment in northern Europe. Several species of birch have been bred to create ornamental cultivars with bark or foliage that are particularly interesting for gardening, and these cultivars are sometimes available from nurseries and garden stores.