The Douglas fir (Pseudotsuga menziesii) is one of the most common and well-known trees in North America. It is an easily recognizable coniferous tree of the pine family that grows from near sea level to very high altitude, occasionally over 10,000 feet elevation. (Photo from Gary Halvorson, Oregon State Archives)
Douglas firs are among the tallest trees in the world, often surpassing 300 feet (91 meters) in height. Officially, the tallest Douglas fir is located near the Southern Oregon coast and is over 325 feet in height. There may be taller Douglas firs in the very moist coastal area of extreme northwest Oregon and southwest Washington, but it is difficult to access the area due to the profusion of trees and brush.
Douglas firs often grow close together in dense forests. The soil must be deep and well draining for the tree to grow well, and it doesn't grow in thick, dense, poor draining soils. It grows best in slightly acidic soils.
These firs grow to an enormous size, particularly in the Pacific Northwest coastal areas, and the forests harbor numerous animal species.
The tree is perhaps most known as the Christmas tree, though economically, it has far more uses than just for Christmas trees. The tree is neatly cone shaped, pointed at the top and larger at the base, with wide spreading and densely needled branches especially low on the tree.
The branches are covered with needles that are firmly attached to the branch. The needles are small, rarely over an inch in length, and are a deep green to a grayish green in color. The needles and tree are richly aromatic, and the young needles are sometimes used to make a flavorful tea.
Lower limbs of older trees die off, as they are shaded from sunlight by the branches above, but usually remain attached to the trunk for a long time. It is not uncommon for younger trees to have branches laden with needles that reach to the ground.
The bark of saplings is white-gray in color and contains numerous pockets of sweet smelling pitch. As the tree grows older, the bark becomes cracked and reddish gray. Very large and old trees will often have lichens growing on the bark, most often on the leeward side of the tree.
The cones are not large in length or diameter, and are narrow at both the tip and the base. They have bracts that rather resemble the rear halves of a squirrel jumping down a hole.
The seeds are small and germinate readily after spending some time in cold temperatures. Initial growth is fast, but it slows down, as the tree grows older.
The wood is of great economic importance, especially in the Pacific Northwest, and is primarily used for lumber. It is also an much used firewood.
Douglas fir often grows in mixed forests of Ponderosa Pine, Yew and Mountain Hemlock.
While the Douglas fir may be best known as the Christmas tree that so many people purchase each year in December, its uses and importance is far greater than this single purpose.