138 Betula papyriferaCommon Names: canoe birch, paper birch, white birch Family: Betulaceae (birch Family)
The familiar paper birch is a slender and graceful deciduous tree with white bark that separates along horizontal slits and peels into thin papery layers, exposing an underbark which is pale orangeish brown. The bark has a chalky covering that rubs off easily, and this is one way to distinguish this tree from other birches with white bark. The paper birch usually gets 50-70 ft (15.2-21.3 m) tall, but can get as tall as 100 ft (30.5 m). It has a conical form and a rather sparse, open crown, more so in age. The leaves are ovate to heart-shaped, toothed, 2-3 in (5.1-7.6 cm) long, and dark green, turning yellow to orange in fall. The staminate (pollen-producing or male) flowers are in hanging catkins, 3-4 in (7.6-10.2 cm) long, and the pistillate (female) flowers are in semi-erect conelike clusters about an inch long. The trees bear both kinds of flowers and these appear before the leaves in early spring. Botanists recognize several varieties of paper birch, and a few naturally occurring hybrids with other birches have been identified. Horticulturists have selected a few cultivars, including 'Chickadee' which is described as especially narrow, and 'Snowy' which is supposed to be resistant to the bronze birch borer.
Paper birch has one of the widest ranges of any North American tree. It grows from coast to coast, from Pacific Alaska across all of Canada to Atlantic Newfoundland, as far north as trees grow. Southward, paper birch is common in New England, New York and the Great Lakes states, and grows in all the states in the northern tier. Outlier populations of paper birch occur in the high mountains of West Virginia, North Carolina and Colorado. Paper birch often grows in pure stands in rocky uplands and along streams. In the southern parts of its range it is confined to high slopes, generally on the cooler north or east sides.
CulturePaper birch grows very fast in youth, but remains a tree of moderate proportions. It rarely lives more than 100-150 years, and rarely exceeds 70 ft (21.3 m) in height. Light: Paper birch does best in full sun to partial or dappled shade. Moisture: Like other birches, paper birch has a shallow root system and should be watered during dry spells. It is highly susceptible to the bronze birch borer when not watered enough. Hardiness: USDA Zones 2 - 7. Paper birch is extremely cold hardy. It almost never grows naturally where average July temperatures exceed 70ºF (21ºC). Trees grown in warmer climates often succumb to bronze birch borers. Propagation: Propagate paper birch from fresh seeds, which are produced in prodigious numbers. Seeds that have been stored may require cold, moist stratification before they will germinate. The tiny seedlings are particularly fragile and must be coddled for their first few years. Paper birches can also be propagated from cuttings.
Paper birch is usually cultivated for its highly ornamental bark which is especially attractive in winter, framed by its delicate lacy twigs. A small group of paper birches looks great in front of dark green evergreen conifers. American Indians used the tough, light weight bark of paper birch to cover their wigwams and birch bark canoes, as well as to make baskets, water-tight containers and dishes. They also made a tea from the leaves, a sweet syrup from the sap, and used decoctions of the inner bark for various medicinal purposes.
Because it is more resistant to the bronze birch borer and somewhat longer lived, paper birch is a better choice for American gardeners than European white birch, which is often (unfortunately) easier to obtain.
Paper birch is one of the first trees to establish following forest fire. After a devastating fire, paper birch germinates by the millions and forms dense, monospecific stands. Beavers eat the inner bark, moose and deer browse the twigs, ruffed grouse eat the leaf buds, and birds and mice eat the seeds.
Steve Christman 10/30/00; updated 11/22/03, 3/26/08