A Douglas fir tree is a large coniferous evergreen tree native to North America, Mexico, and eastern Asia. There are five known species of the tree, all in the family Pinaceae. It can be found in high elevations, between 6,000 and 10,000 feet (1,830 and 3,050 meters) above sea level, and thrives in cool, moist, mountainous areas. Large forests of the trees once grew in the southern Rocky Mountains in the United States, but these have mostly been cut for their wood.
The tree we know as the Douglas fir tree was first discovered by Archibald Menzies, a Scottish naturalist and physician, in 1791. It was rediscovered by David Douglas, a Scottish botanist, in 1825, which is where its name originated. Douglas introduced the tree into cultivation in England in 1826.
The Douglas fir tree is tall, and has a broader shape than a spruce tree. In its youth, the tree has a definite pyramid shape, but this becomes less defined with age. It is shade tolerant and drought resistant, and is often found growing alongside Ponderosa pine. It grows rapidly, and when fully matured, has a thick bark known for its ability to resist fire.
The tree grows to a height of 40-260 feet (12-80 meters), and the branches can spread from 12-20 feet (4-6 meters) in width. In America, the Douglas firs found on the Pacific coast grow to be the second tallest tree in the country, and can live to an age of over 1,300 years. The foliage is blue-green to dark green in color, and consists of needles about one inch (2.5 centimeters) in length.
Douglas fir wood is valued for its quality and durability. It is used extensively for all types of building and construction, from furniture and ship building, to paneling and wood floors. Its attractive, rich color appeals to home owners, and its superior strength makes it suitable for almost any building application.
The Douglas fir tree is also the most commonly sold Christmas tree in the United States. It is used this way because its needles do not fall off as easily as other types of evergreens. A young Douglas fir tree will have extremely dense growth, which adds to its appeal as a Christmas tree. It is typically trimmed to give it a classic cone shape, and then sold to consumers from tree farms around he holiday season.
In addition, the Douglas fir tree is useful to wildlife in many different ways. Its seeds are eaten by squirrels and chipmunks, and deer and elk are known to browse its leaves. This evergreen is also prone to infestation by pests such as western spruce budworm, cottony aphids, and bark beetles, any of which can destroy a healthy Douglas fir in very little time.