Alnus rubra of the Family Betulaceae

Red alder, Pacific red alder, western alder, Oregon alder

Average height is 90 feet with diameters of 1 to 4 feet. Average weight is 31 pounds per cubic foot with a specific gravity of 0.53.

Wood dries easily and quickly with very little degrade and slight movement in service. Alder is moderately light. Wood works well with both machine and hand tools. Experts recommend a reduced cutting angle to avoid problems in planing. Cutting tools should be kept sharp to reduce blunting. Wood has good nailing and gluing properties. Finishes well. Wood has medium density, medium crushing strength; low stiffness; low bending strength; low shock resistance. There is no visible boundary between heartwood and sapwood.

Red alder’s range is the West Coast of the United States from California north to Alaska and Canada. Red alder is a water-loving, quick-growing tree that thrives in moist conditions. For years, red alder was appreciated more as a source of fuel than as a commercial timber. Red alder’s stock has been rising steadily, however, as a commercial timber.

Since the mid 1900s, red alder has been gaining in popularity among woodworkers. In our last look at this species Wood & Wood Products examined the aggressive marketing that helped turn alder from a one-time “weed” tree into a sought-after species. Like mesquite, alder was once considered a nuisance. It was bulldozed to clear space for softwoods like Douglas fir and hemlock.

From Fuel to Furniture
It took a coordinated effort for alder to be appreciated by the public and by those who deal in timber. “Formerly, red alder was considered fit by lumbermen only as a fuel,” writes Donald Culross Peattie in his book A Natural History of Western Trees, “but the Northwest furniture companies began less than 50 years ago to realize that they need not import eastern hardwoods for all of their work, and today more red alder is cut than any other Northwest hardwood, including trees with such famous reputations as oak, birch, maple and poplar.”

What turned the tide in red alder’s favor is its availability and very good properties. The wood machines well and is excellent for carving and turning. It nails, screws and glues well and best of all it is easily sanded and takes paint and finish very well. Alder is a wood that works well with a variety of other furniture woods, taking a stain to complement such woods as walnut and cherry.

Red alder is available in dimension stock, lumber and some veneer. It is sometimes used as 3-ply or 5-ply laminated wood, but in general it is used in solid wood furniture, such as mid-priced kitchen chairs, and dozens of other uses such as kitchen cabinets, frames, ladder rungs and the inner soles of athletic shoes.

Other uses for the wood include turnery and carving, plywood corestock, utility plywood, chip baskets, small laminated articles, woodenware, furniture parts, sashes, doors, panel stock and millwork.

Reviving Forests
Peattie says that as popular a wood as alder has become, it is also valued as a species that “moves in swiftly on burned over lands. Owing to the abundance and lightness of its seeds and their high viability, it reproduces well and grows swiftly, enriching the soil and providing shelter from sun and wind for other trees. Then in 50 to 80 years, old age begins to overtake this short-lived nurse tree and the valuable softwood timber trees outstrip and at last replace it.”

Alder trees do have an amazing ability to spring up and thrive on land that has been ravaged by fire, earthquakes or logging. While alders grow quickly, the species is not generally a long-lived one. The trees mature in 25 to 40 years but will begin to deteriorate by 60 to 80 years of age.

Red alders have a wide height range. Most often the trees grow to between 60 and 90 feet, but some of the alders are as short as 40 feet while other trees can grow to 100 to 120 feet or more. Peattie says that some of the tallest red alders are found in the Puget Sound region.

Alder’s Many Species
Species closely related to our red alder include Alnus glutinosa, which is know by the trade name common alder. This tree is native to Europe and North Africa but is also found in Russia, western Asia and Japan. Like our native alder, the common alder thrives near water or on moist sites. Both common alder and red alder have many of the same uses but it too was unappreciated as an inferior furniture wood until its stock rose and is now a popular choice for solid wood furniture. Alder from Europe and Asia is considered too valuable to use as a fuel but at one time it was used to make gun powder. Alder is sometimes sliced into veneer but in general the species is used more frequently as lumber.

In the United States and Canada, other alders include sitka alder (Alnus sinuate), which is mostly shrub size in the areas where it grows in the United States and Canada, but tree-sized in the higher elevations of Oregon and in Alaska. This tree has little commercial value as a timber tree, but it is valuable for the role it plays in retarding erosion by streambeds. Mountain alder or thin leaf alder (Alnus tenuifolia) is another shrub-like tree in most areas where it grows except for the mountains of Colorado and in Northern New Mexico where it can grow to 30 or 35 feet. This tree has no commercial value to speak of but it has an interesting reputation as the friend of the explorer according to Peattie. “The early explorers and pioneers soon learned that the presence of this species denoted running water.”

Other domestic alders include the California alder, Alnus rhombifolia, also called white or western alder and Arizona alder, Alnus oblongifolia. These two species can grow as tall as 60 feet and like the others are found near water.