Hemlock, western (Tsuga heterophylla)
Western hemlock is an evergreen conifer native to north west America, but commonly planted in the UK for timber.
Common name: western hemlock
Scientific name: Tsuga heterophylla
UK provenance: non-native
Interesting fact: Queen Victoria regarded this tree for its timber so highly, that she requested its name was changed to Tsuga albertiana, in honour of her husband, Albert. This change was only temporary, however, and its original name, Tsuga heterophylla, is now used.
What does western hemlock look like?
Overview: broadly conical in habit with a narrow crown, mature trees can grow to 45m (taller in their native habitat), and have characteristic long, drooping branch tips. The bark is dark brown with rugged ridges.
Leaves: needle-like leaves are soft, rounded and flat, with two white bands on the underside.
Flowers: cones are small and pendulous, with thin, flexible scales. Immature cones are green and mature to grey-brown, with thin, papery scales.
Look out for: the needles along the sides of the twig are longer than those on the top. When crushed, needles are grapefruit scented. Each needle has two white stripes on the underside. Cones are unstalked.
Could be confused with: other planted hemlock-spruces. It is not related to the highly toxic herb hemlock, but shares its name due to the similarity of the scent of their foliage.
Identified in winter by: it is an evergreen so its features are present year round.
Where to find western hemlock
It was introduced to Britain in the 19th century by plant hunter David Douglas, and is now one of the most common conifers found in the UK. Best suited to moister climates, western hemlock has rapid growth and regenerates freely in a wide range of upland forests.
Value to wildlife
Western hemlock plantations are often very dark as they cast dense shade, meaning few plants and therefore wildlife can live beneath them.
Mythology and symbolism
In some ancient North American traditions, western hemlock was an important herb for women. Among the Kwakwaka’wakw people, female warriors made head dresses from western hemlock, for ceremonial dances.
How we use hemlock
It is mainly grown for timber and wood pulp in the UK, although it is also grown as an ornamental tree in parks and gardens. Western hemlock wood is commonly used for roofing and boxes as it holds nails well without splitting.
Western hemlock is generally considered to be free from pests and diseases.