Category Archives: Botany

Western Hemlock: A Grinch of Greens

Many of us bring evergreen boughs or trees into the house this time of year.

Branchy stick glued to piece of paper

Herbarium specimen of western hemlock (Tsuga heterophylla)
Courtesy of the University of Washington Herbarium

And how many of us have made the mistake of bringing Western hemlock (Tsuga heterophylla) into our homes—only to find needles everywhere. Everywhere, no matter how fresh the branches.

The Internet tells us that hemlocks are “not the best” for seasonal decorations.

When I worked at the University of Washington Herbarium, occasionally I would get a request for a specimen of Washington’s state tree, western hemlock, from a student in another state. Sorry, kid.

Western hemlock, while a lovely tree in the forest, is a complete failure on a herbarium sheet. A lush branch in the plant press becomes a skeletal stick and a fat packet of loose needles.

Unfortunately, these qualities make our state tree a Grinch of holiday greens.

Green hemlock branches and leaves with small round brown cones

Fresh branch of western hemlock (Tsuga heterophylla)
Photo: Ben Legler

However, it has many other stellar qualities, as you can learn in Lowland Western Washington Native Trees an educational brochure that WNPS developed in 2013. So much to discover on the Landscaping Resources page on the WNPS website, as well as in the resources developed by the Starflower Foundation!

Western Hemlock (Tsuga heterophylla) grows 50-200 feet tall.

It’s shade tolerant and grows in dry to moist sites.

Graceful with narrow crown and slender, it has the drooping top characteristic of hemlocks. Branches are down-sweeping and spray-like, with feathery foliage.

Needles are short, flat, and green with white lines on their lower surfaces.

Branched stick glued to piece of paper

Mountain hemlock (Tsuga mertensiana) herbarium specimen
Courtesy of the University of Washington Herbarium

Cones are numerous, small, and brown.

Bark is rough and reddish-brown.

This very common forest tree grows well in humus-rich soil and decaying wood. It provides winter cover for birds and food for juncos, siskins, chickadees, grouse, finches, crossbills, chipmunks, squirrels, and deer.

In urban settings, dry soils may shorten its life—and it may grow too large for your site. Its relative, the Mountain Hemlock (Tsuga mertensiana), is an excellent garden tree. But… it too is a Grinch of holiday greens.