Identifying characteristics:
The sweet birch has a dense, pyramidal form, becoming rounded and
irregular with a tall, straight trunk. Trees are usually 50 to 60 feet tall
(or 80 feet in the wild). The thin, papery leaves
are simple, alternate and doubly-serrate, with a heart-shaped or unequally
rounded base. They are 2.5 to 6 inches long, glossy and dark green above
and paler and hairy on the veins beneath, occurring in pairs on lateral
spur shoots on older branches. This species exhibits the best autumn color
of all commonly cultivated birches, turning a rich, golden yellow in the
fall. Male and female flowers are
produced in separate catkins on the same tree: male flowers in slender,
drooping, reddish-brown, 3- to 4-inch-long catkins and female flowers in
short, upright, pale green catkins. The fruits
are small, winged nutlets, each occurring on glabrous, 3-lobed bracts in
a 1- to 1.5-inch-long, upright cone (strobile). Fruits ripen by early fall
and the seeds are wind-dispersed. The sharp-pointed, conical, buds
are covered by loose, mostly hairless, chestnut-brown scales. Short spur
shoots have terminal buds (which are absent on long shoots). Young trees
have shiny, close-fitting, dark reddish-brown bark with conspicuous horizontal
lenticels. This species is sometimes called the "cherry birch"
due to the similarity of the bark
to that of the black cherry (Prunus
serotina). Older trees have grayish-black bark with thin, irregular,
scaly plates.
Similar species:
Ecology:
Distribution: Sweet birch is native to the eastern woods from southern
Quebec, southern Ontario and southern Maine, south to the Appalachian Mountains
in northern Alabama and Georgia.
Habitat: The sweet birch is found in the open and in wooded uplands on moist, east- or north-facing slopes. It is a medium-rate grower, performing best in deep, rich, moist, well-drained, slightly acid soils, but often found on drier, rocky sites. It tolerates the heavy soils of the Midwest. Although the sweet birch is resistant to the bronze birch borer, it is susceptible to most pests and diseases common to birches including birch skeletonizer, leaf miner, seed gall mite, canker, leaf rust and leaf spot. Birches are easily damaged by ice and snow breakage.
Uses:
Wood: The wood is similar to that of yellow
birch (B. alleghaniensis) but second to it in economic importance.
It is hard, medium-heavy and strong, but tends to warp and is difficult
to season. The wood deepens in color upon exposure to air, becoming dark
brown, tinged with red and sometimes passes for mahogany. It is an excellent
firewood. Young trees and saplings were harvested by pioneers for extracting
wintergreen oil, a compound now manufactured artificially. The sap can be
tapped in late winter and fermented with corn to make beer.
Wildlife: Seeds are eaten by songbirds, and grouse feed on the catkins, buds and seeds. Moose, deer, porcupines and beavers feed on the twigs and young leaves.
Horticulture: Although the white-barked birches are often more popular in landscaping, the sweet birch is an attractive tree for planting in parks and naturalized areas.
