Douglas-fir is a large tree, reaching 85 metres on British Columbia’s (B.C.) coast and 42 metres in the Interior. The oldest trees can be more than 1,500 years old. Due to its strength, Douglas-fir is used for building and construction, and it is one of the finest timbers for heavy structural purposes, including glue-laminated timber (glulam) beams and roof trusses.
Where it grows
There are two varieties of Douglas-fir in B.C.: coastal and interior. The coastal variety (var. menziesii) is found along the southern mainland coast and across Vancouver Island, except for the very northern tip. The interior variety (var. glauca) occurs throughout southern B.C. and as far north as Takla Lake near the Yukon border.
Douglas-fir grows in pure, even-aged stands, usually after wildfires; in uneven-aged stands; and in a number of mixed-species stands. The two varieties are found in quite different environments. Interior Douglas-fir can be found in a range of habitats including open forests with pinegrass and moss understory. On the coast, forests are more productive and Douglas-fir grows in mixed stands of western red cedar, hemlock and grand fir.
Did you know?
The common name for Douglas-fir is hyphenated because it is not a true fir. Because of its similarity to other species, it has been called pine, spruce, hemlock and true fir. In 1867, it was given its own genus—Pseudotsuga—which means false hemlock.
Identifiable Characteristics
Douglas-fir is a large tree, reaching 85 metres on the west coast and 42 metres in the interior. Commonly living to be at least 500 years of age, the oldest trees can be more than 1,500 years old. Older trees have a long, branch-free trunk and a short cylindrical crown with a flattened top.
Young Douglas-fir bark is smooth and grey-brown with gummy resin-filled blisters. The bark becomes very thick and deeply grooved with age, growing dark reddish-brown ridges.
Needles are flat with a pointed tip. The upper surface is bright yellowish-green with a single groove down the centre; the lower surface is paler. The needles appear to stand out around the twig. Cones are 5 to 11 centimetres long, turning from green to grey as they mature. Three-pronged flowers are visible between each scale. Seeds are winged at the tip.
