What is Western Hemlock?
The Wood Guide · The wood register
Softwood · referenceWestern hemlock
An evergreen conifer from the North American west coast that reaches seventy metres — and yields pale, even-textured wood you would not recognise it in.
- Tsuga heterophylla
- Up to 70 m, exceptionally 83 m
- Trunk up to 2.7 m
Western hemlockTsuga heterophylla
Western hemlock
An evergreen conifer from the North American west coast that reaches seventy metres — and yields pale, even-textured wood you would not recognise it in.
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Western hemlock in brief
Its natural range runs from south-east Alaska to northern Sonoma County in California.
The species name heterophylla means "with different leaves", a reference to the variable shape of the needles on one and the same branch. It is the largest species of the genus Tsuga: trees reach seventy metres, exceptionally even eighty-three, with trunk diameters up to 2.7 metres.
Young trees have a conical crown with a characteristic drooping leader — the hemlock nods its head, which is how you recognise it from afar. Older trees develop a cylindrical crown with no branches in the lowest thirty to forty metres.
The bark is thin, brown and furrowed, closely resembling that of the Douglas fir. In the forest the two are regularly confused; the nodding top and the shorter needles give the hemlock away.
- Botanical
- Tsuga heterophylla
- Origin
- west coast of North America, Alaska to California
- Height
- up to 70 m, exceptionally 83 m
- Trunk diameter
- up to 2.7 m
- Characteristic
- drooping, nodding top
- Wood
- pale, even-textured, little resin
To be fair: hemlock is not very durable. It belongs indoors or under cover, and outdoors only when treated. It can also give splinters that quickly become inflamed — carpenters know hemlock as the species you put gloves on for.
What characterises hemlock
Pale and even
Light beige to almost white, with little colour difference between heartwood and sapwood and a fine, regular grain.
Low in resin
Unlike pine or larch, hemlock contains hardly any resin — so it takes paint and stain evenly.
Good strength-to-weight ratio
Strong enough for indoor structural work, and light relative to that strength.
Moves little
Once properly dried it is dimensionally stable, which makes it suitable for interior doors and frames.
What hemlock is used for
| Use | Suitable? | Why |
|---|---|---|
| Interior doors and frames | Excellent | Dimensionally stable, low in resin, paints evenly |
| Indoor construction | Good | Good strength-to-weight ratio |
| Interior wall cladding | Good | Calm look, takes finishes evenly |
| Sauna | Good | Low in resin and doesn't get hot to the touch |
| Paper and board materials | Widely used | Long, even fibre |
| Untreated outdoors | Not recommended | Not very durable |
Hemlock splinters are known for quickly becoming inflamed. Wear gloves when handling rough hemlock, and sand smooth anything that will be touched.
Frequently asked questions about western hemlock
Is western hemlock the same as Douglas fir?
No, although the bark looks similar and they are confused in the forest. Hemlock is Tsuga heterophylla, Douglas fir is Pseudotsuga menziesii — a different species with much more durable wood.
Can hemlock be used outdoors?
Not untreated; it is not very durable. Treated and under cover it is possible, but for real outdoor uses Douglas fir or larch are better choices.
Why is it called heterophylla?
It means "with different leaves" and refers to the variable needle shape on one and the same branch — a characteristic of the species.
How tall does a western hemlock grow?
Up to seventy metres, with outliers up to eighty-three metres. It is the largest species of the genus Tsuga.
Hemlock in perspective
A giant in the forest and a modest wood in the home.
Have a question about your project? Just ask — we're happy to help.
Tsuga heterophylla · Oregon — Rvannatta, CC BY-SA 3.0 · Tsuga heterophylla — Ebustad, Public domain · Photo via Wikimedia Commons: Tsuga heterophylla — Willow & Monk, CC BY 2.0