About

Tsuga canadensis, also known as Canadian hemlock, eastern hemlock-spruce, or eastern hemlock, and in the French-speaking regions of Canada as pruche du Canada, is a coniferous tree in the pine family, Pinaceae, native to eastern North America. It is the state tree of Pennsylvania. Eastern hemlocks are widespread throughout much of the Great Lakes region, the Appalachian Mountains, The Maritimes and the Northeastern United States. They have been introduced in the United Kingdom and mainland Europe, where they are used as ornamental trees.

Eastern hemlock populations in North America are threatened in much of their range by the spread of the invasive Hemlock woolly adelgid, which infests and eventually kills trees. Declines in population from hemlock wooly adelgid infestation have led to Tsuga canadensis being listed as Near Threatened on the IUCN Red List.

How to grow it

Tsuga canadensis has long been a popular tree in cultivation. The tree's preference for partial shade and tolerance of full shade allows it to be planted in areas where other conifers would not easily grow. In addition, its very fine-textured foliage that droops to the ground, its pyramidal growth habit, and its ability to withstand hard pruning make it a desirable ornamental tree. In cultivation, it prefers sites that are slightly acidic to neutral with nutrient-rich and moist but well-drained soil. It is most often used as a specimen, for a screen, or in small group plantings, though it can also be trained as a dense formal hedge. It should not be used on roadsides where salt is used in winter, as its foliage is sensitive to salt spray. It is also poorly adapted as a windbreak tree, as wind exposure causes dieback in winter. It has several drawbacks, such as a fairly low tolerance of urban stress, intolerance for very wet or very dry soils, and susceptibility to attack by the hemlock woolly adelgid, though this is treatable.

Where it grows

T. canadensis occurs at sea level in the north of its distribution, but is found primarily at elevations of 600–1,800 m (2,000–5,900 ft). It ranges from northeastern Minnesota eastward through southern Quebec and into Nova Scotia, and south in the Appalachian Mountains to northern Georgia and Alabama. Disjunct populations occur in the Piedmont region, northern Alabama, western Ohio and into Indiana, as well as western Wisconsin and eastern Minnesota. In Canada, it is present in Ontario and all provinces to the east except Newfoundland and Labrador. Its range completely overlaps that of the closely related Tsuga caroliniana.

Uses

American pioneers made tea from the tree's leafy twigs and used its branches as brooms. Tea can be made from the needles. The inner bark, which is best in winter and coming into spring, can be eaten raw or boiled; it can also be used to make flour.

Other Tsuga plants

Western Hemlock · Mountain Hemlock · Hemlock