Eastern, or Canadian hemlock is an evergreen conifer tree with a pyramidal growth habit and a relatively rounded top, the highest leader often drooping. The ends of branches also droop slightly, giving it a "relaxed" look. It can be clipped and trained as a shrub, and numerous cultivars exist.
Leaves are needles, alternate, flattened, ½–1 inch long, undersides whitish, with a rounded tip and slender stalk, appearing in two, somewhat flattened rows.
Bark is orangish- to grayish-brown, with scaly plates, with or without furrows.
Twigs are hairy, pale brown to gray or yellowish-brown.
Conifers don't technically "flower," but pollen is shed March–April.
Fruits are small cones ½–1 inch long, persisting handsomely through winter; cone scales woody or somewhat papery, straight, not shiny, with rounded tips. Seeds winged.
Similar species: Only one member of the pine family is native to Missouri, and that is the shortleaf pine (Pinus echinata). All other members of the pine family (including larches, spruces, firs, true cedars, and Douglas fir) that live in Missouri are nonnatives that have been cultivated and only rarely persist in wild habitats on their own, and rarely if ever spread.
Height: to 50 feet (maximum about 100 feet); can be trained as a clipped hedge 3–5 feet tall.
Cultivated statewide; known to reproduce on its own in only one location in Missouri, in Oregon County.
Habitat and Conservation
In our state, almost always found in cultivation or at old homesites. It prefers moist upland forests and bluffs. If you are planting one, note that it handles urban conditions but is not pollution tolerant. It also does not tolerate poorly drained, heavy soils or extended drought and should not be planted where irrigation is impossible. It can grow in full sun but is also shade tolerant; it is one of the few larger evergreens suitable for planting in moderate shade.
This tree is almost always encountered only in landscaping in our state. However, based on one instance in Oregon County, we know it can reproduce and spread on its own. But otherwise, if you encounter it on a hike, it was almost certainly planted there at some point: look around for a cistern, old home foundation, and other persisting garden plants, such as lilacs and irises, nearby.
The fine-textured foliage blends well into many garden settings. Despite its relatively slow growth, it can form a tall evergreen screen under varying light conditions. A close relative, Carolina hemlock (Tsuga caroliniana), is not common but is also a good evergreen tree for urban settings.
There are many native trees that are preferable for planting, for they are best-adapted to our soils and climate and offer superior nutrition and habitat for native animals. Planting trees, native or not, not only beautifies an area, but also can lower your home energy bill — and reduce our country's energy needs as well. Exploiting energy resources necessarily disturbs the environment in large and small ways. Your utilities company can provide you with energy-saving tree-planting ideas.