Common names: Douglas Fir 

Irish name: Giúis Dhúghlais 

Latin name: Pseudotsuga menziesii 

Family: Pinaceae 

Origin: Non native 

Tree type: Evergreen conifer

How it looks

This is a tall, slender and conical conifer which can reach heights of up to 60m and can live for up to 1,000 years. It is the largest conifer after the Coast Redwood. Confusingly, the Douglas fir is not true fir tree or even part of the family of Firs – (Abies); nor is it a Tsuga (a hemlock), hence the first part of its Latin name is Pseudotsuga (false hemlock). 

Shape, bark, twigs 

As the tree matures, the bark changes from a grey colour to reddish. Resinous blisters are visible on the trunk in younger trees. 

Buds 

The buds are shiny, long and pointed and covered with chestnut-coloured overlapping scales. 

Leaves 

Needles up to 3cm long. They are pointed and flat with a row of white dots on the bottom and soft to the touch. They are held singly on the twig and grow all around it. They have a has a short stalk at the base and a grooved upper surface. Crushed needles produce a citrus smell. 

Cones

The best way to identify a Douglas fir is through its cones as they are quite distinctive. They feature papery scales, with a small, brown, three-pointed leaf known as a bract positioned between each scale. The cones and developing seeds are often likened to the hind legs and tails of mice, which folklore suggests seek refuge within the cones during forest fires.

Similar species 

The bigcone Douglas fir (P. macrocarpa), a smaller species important only for erosion control, bears cones 10 to 15 cm (about 4 to 6 inches) long. 

Where to find it

It is native to Northwest America and eastern Asia. It is the state tree of Oregon. It was brought to Ireland and the UK by botanist David Douglas in 1827. The tallest tree recorded in Ireland is a Douglas-fir. This can be found in Powerscourt, Co. Wicklow and measures fifty-six metres in height. 

Cultural importance

The botanical name for Douglas fir, Pseudotsuga menziesii, was attributed to it in honour of the Scottish botanist and naturalist Archibald Menzies, who discovered the tree in North America in 1792, whilst its common name was allocated in honour of David Douglas. However, the Indigenous Peoples of the Pacific Northwest of America used and interacted with Douglas Fir for hundreds of years before these men ever made it to the shores of the North America.  

Archaeological investigations in British Columbia, Canada suggest that Indigenous communities were stripping bark from Douglas Fir trees as early as 450 BC (over 1500 years ago) for use as a smokeless, high temperature and spark free fuel source. There is also evidence to suggest that these communities were using slabs of Douglas fir bark to make temporary shelters. Likewise, ethnographic studies indicate that they were using the wood, boughs and branches to make spear shafts, fishhooks, fishing nets, and to cover the floors of lodges and sweat lodges. It is thought that the needles were even used to cover food like a type of ancient cling film. The branches were also used for spiritual purposes, such as purifying spaces and warding off ghosts. 

In California and New Mexico, Indigenous communities used different parts of the Douglas fir for medicinal purposes: tea made from its needles was used as a cure for rheumatism, tea made from the bark was used to treat colds, headaches and stomach ailments, and the resin of the tree was used to make poultices for cuts. However, they also used the tree for other practical purposes such as making pitch from the resin for waterproofing jugs and canoes, and weaving baskets from its roots. 

The Douglas fir was highly valued by the Indigenous Pueblo People of New Mexico who used its timber to construct their homes, and incorporated twigs of the tree into their dancing costumes. Furthermore, the ancestral Pueblo People of Chaco Canyon, who occupied this region between c. 850-1150 AD, went to great effort to source Douglas fir from thousands of miles away to build their Great Houses – large wooden buildings that were likely used for gatherings, perhaps for ceremonial or governmental purposes. Prayer sticks made from Douglas fir have also been discovered in archaeological excavations of ancestral Pueblo occupation sites.  

The Douglas fir is associated with protection as can be seen in the way it was traditionally used to ward off spirits. Similarly conveying these protective qualities, a creation story common to many Indigenous communities of the Pacific Northwest tells that once a Douglas fir offered shelter to a mouse and any others seeking refuge during a forest fire. The mice sheltered under the scales of the tree’s fir cones with their feet and tails exposed. If you look closely at a Douglas fir cone, you can see what looks like the feet and tails of mice protruding from underneath its scales! 

Douglas fir was logged extensively by Euro-American settler populations during the 1850s. It is said that it is the tree that built the state of Oregon and was designated the state tree of Oregon in 1939. Following concerns in the 1880s over the depletion of Douglas fir forests, management practices were put in place to rehabilitate them. 

After Douglas fir was introduced to Ireland in the 1850s, it became a favourite specimen tree. With the advent of State forestry in Ireland, the tree was extensively planted in stands throughout the country as a source of timber. As such, it has become a common feature of the Irish landscape. 

Value to wildlife

As the trees live to such great ages, these trees develop hollows in their deadwood which provide shelter for birds and bats. As a very tall tree, they make ideal nesting spots for larger birds of prey like buzzards and sparrowhawks. Needles offer a food supply to a number of different moths, while the seeds are a food source for birds and small mammals. Deer love to eat the shoots of Douglas fir. 

Threats

The tree is known to be susceptible to fungal diseases. To learn more about threats to Irish trees, visit ‘Threats to Trees.’  

Uses

They are popular as Christmas trees in North America. They are also grown as ornamental trees in Europe and North America. They are very important timber trees as their wood is strong and durable. Its timber is also referred to as Oregon pine. As the trees can be so large, they can produce very large beams for use in construction. 

References

Clear, T. 1951. Douglas Fir in Co. Wicklow. Society of Irish Foresters, 8-18. 

Mathews, D. and Dady, P. 2008. Douglas Fir Culturally Modified Trees: Some Initial Considerations, Paper presented at the Northwest Anthropological Conference, April 24, 2008: Mathews_and_Dady_2008_Douglas_Fir_Culturally_Modified_Trees-libre.pdf (d1wqtxts1xzle7.cloudfront.net) 

National Biodiversity Data Centre. 2024. Pseudotsuga menziesii - Douglas Fir. National Biodiversity Data Centre. https://species.biodiversityireland.ie/profile.php?taxonId=17258 

Nash, S. E. 2023. Where Did Chaco Canyon’s Timber Come From? Smithsonian Magazine. Where Did Chaco Canyon's Timber Come From? | Science| Smithsonian Magazine 

Woodland Trust. 2024. Douglas Fir. Woodland Trust. https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/british-trees/a-z-of-british-trees/douglas-fir/