Washington State Tree: Western Hemlock

Washington recognizes the Western Hemlock as its official state tree. This evergreen conifer grows 150 to 200 feet tall in Washington's coastal forests, with exceptional specimens exceeding 230 feet. The trunk can reach four to six feet in diameter at breast height. These dimensions made western hemlock Washington's most commercially valuable timber species through much of the 20th century. The tree provided lumber that built homes, schools, and businesses across the Pacific Northwest and shipped worldwide from Washington ports.

The bark appears reddish-brown to gray-brown with deep furrows and thick ridges on mature trees. Young trees display smoother, thinner bark. The foliage consists of short flat needles, each measuring one-quarter to three-quarters of an inch long. The needles attach individually to the twigs rather than in bundles like pine needles. Dark green above and silvery below, the needles create dense shade beneath the canopy. Small oval cones hang from branch tips, measuring just three-quarters to one inch long. These cones distinguish western hemlock from other Washington conifers, which typically produce larger cones.

Western hemlock grows throughout Washington west of the Cascade Range crest. The species thrives in the cool, moist climate of Washington's western lowlands and mountain slopes. Hemlock forests dominate from sea level to elevations approaching 5,000 feet. The tree requires substantial rainfall, flourishing in areas receiving 50 to 80 inches annually. Washington's Olympic Peninsula and Cascades foothills contain some of North America's finest hemlock forests. The species grows in pure stands or mixed with Douglas-fir, western redcedar, and Sitka spruce. Eastern Washington's drier climate prevents western hemlock from establishing naturally east of the Cascades.

The common name is Western Hemlock, distinguishing it from Eastern Hemlock found in Appalachian forests. The scientific name is Tsuga heterophylla. Tsuga is the Japanese word for hemlock trees. Heterophylla means 'various leaves' in Greek, referring to the needles' varying lengths and arrangements. This species belongs to the Pinaceae family, the pine family.

Early Washington loggers called this tree hemlock, Alaska pine, or West Coast hemlock. The name hemlock refers to a supposed resemblance between the foliage and the poisonous hemlock plant, though the tree contains no toxic compounds. Pacific hemlock is another regional name emphasizing the tree's coastal distribution. Washington timber industry workers distinguished between hemlock and 'hem-fir,' a commercial lumber grade mixing western hemlock and true fir species. This lumber category became one of Washington's primary timber products.

Washington selected the Western Hemlock as its official state tree in 1947. The Washington State Legislature passed House Bill 196 during the 1947 session. Governor Monrad C. Wallgren signed the legislation on March 20, 1947. The bill established western hemlock as Washington's arboreal emblem in recognition of the tree's dominance in state forests and importance to the timber economy. No public vote determined the choice—legislators made the selection based on economic and ecological criteria.

Washington picked western hemlock because it represented the backbone of the state's timber industry. By the 1940s, Washington led the nation in lumber production, and western hemlock supplied a substantial portion of that output. The species grew abundantly throughout western Washington, providing a seemingly endless timber supply. Hemlock lumber built military facilities during World War II, contributing to Washington's economic boom. The wood's light color, fine grain, and workability made it versatile for construction, paper production, and manufacturing. Choosing hemlock acknowledged the tree's role in Washington's prosperity.

The tree's ecological dominance influenced the selection. Western hemlock grows more abundantly than any other tree species in Washington's coastal forests. It regenerates prolifically in shade, eventually replacing even long-lived Douglas-firs as forests mature. This ability to thrive beneath other trees gives hemlock the final word in forest succession across western Washington. The species defines Washington's temperate rainforest ecosystems more completely than any competitor. Legislators choosing a state tree in 1947 found western hemlock's combination of economic value and ecological supremacy compelling. The tree represented what Washington forests meant to state identity—productive, abundant, and economically crucial natural resources.

Washington's state flower is the Coast Rhododendron (Rhododendron macrophyllum), designated in 1892. The state adopted its floral symbol more than half a century before selecting the western hemlock. Both the Western Hemlock and Coast Rhododendron represent Washington's native Pacific Northwest flora. The pink-purple rhododendron blooms create spectacular displays in late spring beneath the towering hemlocks. Both species thrive in Washington's moist climate and acidic soils. Hemlock forests provide the filtered light that rhododendrons prefer, creating a natural partnership in Washington ecosystems. Together these symbols capture the layered structure of Washington forests—tall conifers overhead with flowering shrubs below.

The leader provides the most distinctive identification feature. Look for a drooping or nodding top on the tree—the uppermost shoot bends to one side rather than pointing straight up. This drooping leader appears on hemlocks of all sizes and remains visible even on trees exceeding 200 feet. No other Washington conifer shows this characteristic. The drooping tip creates a graceful appearance that distinguishes hemlock from the more rigid profiles of Douglas-fir or true firs. Foresters and naturalists use the drooping leader as the quickest field identification marker.

The needles offer definitive identification upon closer inspection. Each needle grows directly from the twig rather than in clusters. The needles vary in length on the same twig, creating an irregular, feathery appearance. Check the underside of needles for two white stomatal bands—lines of breathing pores that appear as white stripes. These bands distinguish hemlock from similar species. The needles remain on the tree for three to four years before dropping, maintaining dense foliage year-round. Small oval cones hang from outer branches, measuring smaller than most other Washington conifers.

The overall form shows a narrow conical crown when growing in open conditions. Forest-grown hemlocks develop long, straight trunks with narrow crowns reaching toward available light. The branches droop slightly, creating a layered appearance. Lower branches often sweep downward and then curve upward at the tips. In old-growth forests, massive hemlocks develop thick, deeply furrowed bark that appears almost black. The combination of drooping leader, layered branches, and dark furrowed bark on old trees creates the classic Washington hemlock profile found in the state's ancient forests.

The Western Hemlock embodies Washington's identity as a timber state and home to ancient rainforests. Its towering height represents strength and the vast natural resources that built Washington's economy. The tree's ability to thrive in shade and eventually dominate forests symbolizes persistence and long-term success. For many Washingtonians, hemlock forests evoke the state's unique Pacific Northwest character—misty, green, and seemingly endless. Conservation debates over old-growth hemlock forests reflect tensions between economic use and ecological preservation that define modern Washington. The tree stands at the center of discussions about sustainable forestry and wilderness protection that shape Washington's environmental policies.