Canadian Hemlock (Tsuga canadensis)
Habitat.—Cold soils, borders of swamps, deep woods, ravines, mountain slopes. USDA Zones 3-7.
Habit.—A large handsome tree, 50-80 feet high; trunk 2-4 feet in diameter, straight, tapering very slowly; branches going out at right angles, not disposed in whorls, slender, brittle yet elastic, the lowest declined or drooping; head spreading, somewhat irregular, widest at the base; spray airy, graceful, plume-like, set in horizontal planes; foliage dense, extremely delicate, dark lustrous green above and silver green below, tipped in spring with light yellow green.
Bark.—Bark of trunk reddish-brown, interior often cinnamon red, shallow-furrowed in old trees; young trunks and branches of large trees gray brown, smooth; season’s shoots very slender, buff or light reddish-brown, minutely pubescent.
Winter Buds and Leaves.—Winter buds minute, red brown. Leaves spirally arranged but brought by the twisting of the leafstalk into two horizontal rows on opposite sides of the twig, about ½ an inch long, yellow green when young, becoming at maturity dark shining green on the upper surface, white-banded along the midrib beneath, flat, linear, smooth, occasionally minutely toothed, especially in the upper half; apex obtuse; base obtuse; leafstalk slender, short but distinct, resting on a slightly projecting leaf-cushion.
Inflorescence.—Sterile flowers from the axils of the preceding year’s leaves, consisting of globose clusters of stamens with spurred anthers: fertile catkins at ends of preceding year’s branchlets, scales crimson.
Fruit.—Cones at ends of branchlets, pointing downward, ripening the first year, light brown, about 3/4 of an inch long, ovate-elliptical, pointed; scales rounded at the edge, entire or obscurely toothed.
Horticultural Value.—Hardy; grows almost anywhere, but prefers a good, light, loamy or gravelly soil on moist slopes; a very effective tree single or in groups, useful in shady places, and a favorite hedge plant; in open ground retains its lower branches for many years. There are many different varieties produced in the nursery trade. You will find varieties in varying habits, density and variegation.