WSU Clark County Extension

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Western Hemlock

Scientific name: Tsuga heterophylla

Type:Coniferous trees
Plant Requirements
Zone:5 to 8
Sun:Partial shade
Plant Characteristics
Height:100 ft
Width:30 ft
Additional Characteristics



Wildlife value

Description Recognized as the state tree of Washington, Western hemlock is a tall, shade-tolerant evergreen with notable dropping branches.

This Northwest native can grow very large over time. A mature tree can surpass 100’ in height, and 30’ in width. The trunk can swell to a 4’ diameter.

The lacy appearing foliage consists of soft flattened needles which are bright green when new, turning lustrous dark green as they mature. The needles appear 2- ranked, and are ¼” to ¾” long with rounded tips. When examined from below there are white bands on the underside of the needles.

Cones are elliptical, light brown and about an inch in length.

The Western hemlock prefers acidic, cool, moist to wet soils with good drainage. While the best growth may be obtained in full sun, like other hemlocks, the Western hemlocks are quite tolerant of partial to full shade.

It can be found from Alaska to northern California all along the coast. There is also a large band of Western Hemlocks growing in southeastern British Columbia, northern Idaho and northwestern Montana.

Wolly adelgids can be found on the foliage.
For assistance, contact Dr. Charles Brun (, (360) 397-6060 5701
Computing and Web Resources, PO Box 6234, Washington State University, Pullman WA 99164-6234