Tree 26: Douglas Fir
The botanical name Pseudo… signifies that this is not a true pine. The ‘Douglas’ in ‘Douglas Fir’ refers to David Douglas, the Scottish botanist who first introduced the tree to European botanists. The name ‘Menzies’ in ‘Pseudotsuga menziesii’ refers to Archibald Menzies, also a Scot, who first documented the tree on Vancouver Island.
The Douglas Fir is grown widely throughout Europe, Argentina, Chile for its timber. It has also often been planted as an ornamental tree. It was first grown in the UK in 1827, grows best in western areas where rainfall tends to be higher, and favours acid or neutral soils. In New Zealand it is considered an invasive species.
Douglas Firs are amongst the tallest trees on Earth: the Lynn Valley Tree, cut down in British Columbia in 1901, was measured at 126.5 metres (415 feet); the Nooksack Giant, cut down in Washington State in the 1890s, is reputed to have been even taller. According to Forestry England, the tallest tree in England is a Douglas Fir on Exmoor at just over 60m tall. A Douglas Fir in the Scottish Highlands was measured in 2017 at 68 metres which would make it easily the tallest tree in the UK.
Mature Douglas Firs are highly fire resistant, thanks to their thick bark. Their evergreen leaves are flat, soft, flexible needles, green on top with whitish stripes underneath, and grow all around the twigs. The bark of young trees is smooth and grey-green in colour, often with resinous blisters. As the tree matures, the bark thickens, making the tree fire-resistant, and turning reddish-brown.
The needles when crushed give off a pleasing smell of citrus, distinguishing small Douglas Firs from Yews. The needles make a pleasing infusion, especially the young tips which appear in Spring.
Douglas Firs are among the world’s most important timber-producing trees, being widely used in the construction industry where its uses include joists, flooring, roof trusses, cladding and to make plywood. Some wooden houses in North America made from Douglas Fir in the 1800s are still in good condition today. Douglas Firs are often grown as Christmas trees.
Native groups in North America used the bark, needles and resin to make herbal remedies. Its seeds provide food for small mammals. The thick bark of mature trees typically cracks, providing habitat for birds and small mammals, including bats. Tall Douglas Firs make perfect nesting sites for birds of prey such as sparrowhawks.
North America folklore tells stories of mice seeking shelter in the Douglas Fir from forest fires, seen now in the distinctive three-pointed bracts over the seeds of the pine cones