The Eastern Hemlock (Tsuga canadensis), the state
tree of Pennsylvania, is one of the dominant trees of the Commonwealth's
forests. The tree can grow to a height greater than one hundred feet and is
found in every Pennsylvania county, but most commonly in the mountainous
regions. This slow-growing long-lived tree thrives in the shade and may take 250
to 300 years to fully mature and may live for 800 years or more. The hemlock,
identified as an evergreen tree, has flat needles 1/3-2/3-inch long and
1/2-3/4-inch cones that mature from September to October.
Hemlocks were major assets in the lives' of the State's
first settlers because they were used to build log homes and protect settlers'
families from weather and other dangers. Soon, the eastern hemlock was a major
contributor to Pennsylvania's industry. By the end of the 19th century, hemlock
bark was the major source of tannin for the leather industry. In 1896 in the
Commonwealth alone, over 1.3 billion board feet of hemlock was harvested. The
bark was sent to tanneries and the logs to sawmills.
In 1896 the "Father of Pennsylvania Forestry" Dr.
Joseph T. Rothrock stated, "If Pennsylvania were to select one tree as
characteristic of our State, nothing would be better than the Hemlock". A.J.
Downing, the father of landscape gardening in America, called the hemlock the
most picturesque and beautiful of the world's evergreens. In 1927, the
Pennsylvania legislature debated the merits of several nominations for the State
tree, but no decision was reached. In 1931 lawmakers were again asked to make a
ruling, and after considerable debate, the eastern hemlock was adopted June 22,
Hemlocks grow wild in deep forests. Western hemlocks prefer dense shade and
rocky soil, states the Arbor Day Foundation. The Canadian hemlock also is found
on rocky ridges, hills and ravines. The Eastern hemlock is found along stream
banks and where there are moist, cool beds, according to the University of
Hemlock trees are used for a variety of things. The Arbor Day Foundation states
that the Western hemlock is an important part of the lumber industry, used for
and furniture. Hemlocks are also used for rayon yarns and tanning. Landscaping
is another major use of hemlock trees, according to Ohio State University. The
USDA also states that hemlocks are used in prevention of stream bank erosion.
The University of Maine reports hemlock wood to be coarse, brittle when dry,
strong and lightweight, but difficult to work with.
Prepared by Dr. Craig R. McKinley, North Carolina State University