Western Hemlock–Washington State Tree

By Nancy Penrose

In 1947, Washington named the western hemlock (Tsuga heterophylla) as the official state tree. The name “hemlock” comes for a European weed that has a similar type of smell.

The western hemlock is an evergreen coniferous tree that can be found growing along North America’s west coast, from the Kenai Peninsula in Alaska to Sonoma County, California. The tree is also referred to as the Pacific hemlock and west coast hemlock.

It is the largest species of hemlock, growing from 165 to 230 feet on average. The tree’s trunk can be up to 9 feet in diameter. The bark of the tree is brown and thin with deeply grooved furrows. The tree’s crown at maturity has a cylindrical shape, with green, needle-like leaves up to 23 mm long. The glossy leaves, which are almost flat and soft, are irregular in length.

The tree’s cones are relatively small, and green to red-purple when young. As the cones age, they turn brown.

One interesting characteristic of the tree is its drooping new growth at the top. The tree’s branches, in general, sweep downward.

Western hemlocks are extremely shade tolerant. Many times you will find them growing under mature trees. They grow slowly but are also long-lived. Some are over 1,200 years old.

The evergreens trees have been an important source of timber. During earlier periods, the wood was carved into utensils and dishes. These trees are also a food source for deer and elk. When used for landscaping or gardens, the western hemlock is considered an ornamental tree.

If you have a western hemlock growing on your property, or plan to purchase these magnificent big trees, make sure the tree is protected against winter winds and summer heat. It will need moist, acidic soil to establish itself, with regular watering.

Nancy Penrose is owner of Big Trees Inc. (, (tree nursery Snohomish, WA), one of the largest Seattle tree nurserys (visit Big Trees Planting Service page at, specializing in large trees for sale and transplant tree service. For more tips on tree landscaping go to See our video at and connect with us on Facebook at