Birch Tree

Birch trees are fast-growing, broad-leaved trees in the genus Betula, famous for their pale, peeling bark. They grow across the cooler parts of the Northern Hemisphere and are among the first trees to spring up on open ground after a fire or clearing.

Scientific Classification & Quick Facts

Common name	Birch
Scientific name	Betula
Kingdom	Plantae
Phylum	Tracheophyta
Class	Magnoliopsida
Order	Fagales
Family	Betulaceae
Type	Deciduous hardwood trees and shrubs, 30 to 60 species
Habitat	Sunny, moist soil; cannot grow in shade
Native range	Northern Hemisphere
Lifespan	About 50 years
Special feature	Paper birch bark peels in thin plates and does not rot

The Birch Family

Birches belong to the family Betulaceae, which also includes alders, hazels and hornbeams. They are more distantly related to oaks and beeches. Botanists recognize roughly 30 to 60 species, depending on how they count them, and several are now threatened in the wild.

Birches are deciduous, which means they drop their leaves in autumn. They grow in temperate regions and in the cold, snowy boreal forests of the far north, where winters are long and summers are short. Many birches are fairly short-lived for trees. Garden birches often begin to decline after a few decades, especially when they are stressed by heat or dry soil.

What Birches Look Like

The bark is a birch’s most famous feature. Paper birch and silver birch have bright white bark that peels away in thin, papery sheets. The white color comes from a natural substance called betulin, and the bark contains oils that help it resist rotting. Dark marks and scars on the trunk can look a bit like eyes. Other birches have bark that is golden, reddish-brown, pinkish or almost black.

Birch leaves are simple, meaning they are not divided into leaflets. They grow alternately along the twigs, often in pairs on short side shoots, and have toothed edges and a pointed tip. In autumn they turn a clear yellow.

Birches are monoecious, which means each tree has both male and female flowers. The flowers are packed into catkins. Long male catkins hang down and release clouds of pollen in spring, while smaller female catkins stand upright. As the female catkins ripen, they fall apart and release hundreds of tiny seeds, each with two thin wings that help it float on the wind.

Where Birches Grow

Birches grow in many kinds of soil, from river floodplains and rolling hills to rocky slopes, bogs, the edges of swamps and avalanche tracks in the mountains. They are pioneer trees: they need plenty of sunlight, cannot grow in deep shade and are often among the first trees to colonize open land. As a result, they are common in young forests. Over time, slower-growing trees that can grow in shade often take their place.

Kinds of Birch

Photo by: Fons Heijnsbroek

• Silver birch (Betula pendula): a European birch with white bark and drooping branch tips.
• Downy birch (Betula pubescens): a close relative of silver birch that grows in wetter ground and has hairy young twigs.
• Paper birch (Betula papyrifera): the classic white birch of northern North America.
• Sweet or cherry birch (Betula lenta): a medium-sized tree, up to about 20 meters (66 feet), with dark bark and twigs that smell of wintergreen when scratched.
• Yellow birch (Betula alleghaniensis): has shiny, golden, curly bark.
• River birch (Betula nigra): has shaggy, salmon-colored bark and handles wet soil and summer heat better than most birches.
• Himalayan birch (Betula utilis): some forms have some of the whitest bark of any tree.
• Others include the dwarf birch, a low shrub of the Arctic tundra, plus the Dahurian birch, Japanese white birch and water birch.

Weeping birches are garden forms, usually of silver birch, with long hanging branches.

Growing Birch Trees

Soil

Most birches like moist, well-drained soil that is slightly acidic. A few, including some white-barked kinds, can cope with neutral or slightly alkaline soil. Changing your soil’s pH is hard to keep up for the life of a tree, so it is better to pick a birch that suits the soil you already have. Many garden centers and local extension offices can test your soil. In wet places or areas that flood, river birch is the best choice.

Watering

Water matters more to a birch than almost anything else. Birches have shallow roots and like cool, damp soil. If rain is short, water young trees deeply about once a week, letting a hose trickle slowly at the base so the water soaks down to the roots. A layer of mulch helps keep the soil cool and moist. A simple test: squeeze a handful of soil. If it holds together in a ball, it is moist enough.

Temperature

Most birches prefer cool summers. In hot, dry climates they become stressed, and stressed birches are much more likely to be attacked by pests. If you live somewhere with hot summers, choose a heat-tolerant kind such as river birch, and plant it where its roots will be shaded.

Pests

The birch leafminer is a common pest. Its tiny larvae feed inside the leaves in spring, leaving pale blotches that later turn brown. Light attacks rarely kill a tree but can weaken it.

A more dangerous pest is the bronze birch borer, a beetle whose larvae tunnel under the bark of stressed trees. Keeping your birch well watered is the best way to protect it.

Uses of the Birch Tree

As Wood

Birch wood is pale, strong, easy to work and fairly inexpensive. It is used for furniture, plywood, flooring, toys, spools and craft projects, and it is pulped to make paper. Birch also makes excellent firewood that burns well even when the bark is still on. Many people plant birches simply because they are beautiful.

For thousands of years, people have also used birch bark itself. Indigenous peoples of North America built light, waterproof canoes from paper birch bark, and birch bark has been used for baskets, containers and even writing material.

As Sap

In early spring, before the leaves open, birch trees can be tapped for their sap, much like maple trees. The clear, slightly sweet sap is drunk fresh in parts of northern Europe, Russia and China, fermented into traditional drinks, or boiled down to make birch syrup.

As Traditional Medicine

Birch leaves have traditionally been made into a tea to help the body pass more urine, and birch has also been used in folk remedies for sore joints and skin problems. Oil of wintergreen was once made from sweet birch. These are traditional uses rather than proven treatments, so always ask a doctor before using any herbal remedy.

Birch FAQs

Related: Maple Tree