Eastern Hemlock, A Common Tree in North America

Tsuga canadensis, a Long-lived Evergreen that Thrives in Shade

Eastern hemlock has a "nodding" form defined by its limbs and leaders and can be recognized at great distances. Some rank this tree among the "quality plants" to add to the shaded landscape. They are "long-lived, refined in character and have no off-season" according to Guy Sternberg in Native Trees in North American Landscapes. Unlike most conifers, eastern hemlock has to have shade provided by hardwoods to regenerate. Unfortunately, stands of these trees are being damaged by the hemlock wooly adelgid.

Arbor Day Eastern hemlock tree close-up
(Joanne Levesque/Moment Open/Getty Images)

Eastern hemlock (Tsuga canadensis), also called Canada hemlock or hemlock spruce, is a slow-growing long-lived tree which unlike many conifers grows well in shade. Hemlock may take 250 to 300 years to reach maturity and may live for 800 years or more.

The less common Carolina and mountain hemlock are very close genetically to the Eastern hemlock ​Tsuga family of conifers. They have similar needles sprout all around the branch where Eastern hemlock needles occur in flat sprays in the lower branches. More »

The Eastern and Carolina hemlock forest is now under attack and in the early stages of potentially being decimated by the hemlock wooly adelgid (HWA) or Adelges tsugae. Adelgids are small, soft bodied aphids that feed exclusively on coniferous plants using piercing-sucking mouth parts. They are an invasive insect and thought to be of Asian origin. More »

eastern hemlock leaves and cones
A line drawing of the leaves and cones from Britton and Brown's 1913 Illustrated flora of the northern states and Canada. (USDA-NRCS PLANTS Database/Wikimedia Commons)

The soil requirements for eastern hemlock are not exacting but, generally, the tree needs a moist to very moist but well-drained soil. Eastern hemlock grows from sea level to about 2,500 feet in elevation in the northeastern and northern portions of the range. More »

eastern hemlock bark
(Chhe/Wikimedia Commons)

Forestryimages.org provides several images of parts of Eastern hemlock. The tree is a conifer and the lineal taxonomy is Pinopsida > Pinales > Pinaceae > Tsuga canadensis (L.) Carr. Eastern hemlock is also commonly called Canada hemlock or hemlock spruce. More »

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The Range of Eastern Hemlock

Natural distribution map for eastern hemlock
Natural distribution map for Tsuga canadensis (eastern hemlock). (Elbert L. Little, Jr./U.S. Department of Agriculture, Forest Service/Wikimedia Commons)

The northern limit of eastern hemlock extends from outliers in northeastern Minnesota and the western one-third of Wisconsin eastward through northern Michigan, south-central Ontario, extreme southern Quebec, through New Brunswick, and all of Nova Scotia. Within the United States the species is found throughout New England, New York, Pennsylvania, and the middle Atlantic States, extending westward from central New Jersey to the Appalachian Mountains, then southward into northern Georgia and Alabama. Outliers also appear in extreme southern Michigan and western Ohio, with scattered islands in southern Indiana and east of the Appalachians in the middle Atlantic States.

Stand of eastern hemlock and eastern white pine in Tiadaghton State Forest, Pennsylvania
Stand of eastern hemlock and eastern white pine in Tiadaghton State Forest, Pennsylvania. (Note the hemlocks' deeply fissured bark.). (Nicholas A. Tonelli/Wikimedia Commons/CC BY 2.0)

 Check out Virginia Tech Dendrology's image gallery for more eastern hemlock photos. More »

wildfire in the Bitterroot National Forest in Montana
(John McColgan/Wikimedia Commons)

Eastern hemlock is very susceptible to fire because of its thin bark, shallow roots, low-branching habit, and heavy litter deposits. It is possibly the most fire-sensitive mesophytic tree species in its range. More »