Oregon myrtle, often just called myrtle wood, also known as California laurel (Umbellularia californica), is the most expensive wood in North America. The wood, especially the burls, has exquisite grain and color, especially if the logs were submerged for a while before processing.
Colors can range from light brown to dark brown to gray with creamy, gold, silvery, green, and purplish hues. The wood is therefore prized for curios, as well as furniture. Stringed instrument makers (Technical name: luthiers) find that this wood also produces excellent sound in a guitar and violin. In 1869 the golden spike connecting the transcontinental railroad tracks un Utah was driven into the myrtle wood tie.
Myrtle is found only along the Pacific Coast from Southern Oregon south through California. The trees can grow up to 80 feet and can be up to 3 feet in diameter. Although it is a hardwood (that is, it has broad leaves), it is also an evergreen. Myrtle wood trees are harvested and sawn into lumber, but another source for small quantities of the wood is driftwood found on the Oregon beaches.
The leaves of this tree, when crushed, emit a strong odor. “The foliage, when bruised, gives out a most powerful, camphor-like scent. I have been obliged to remove from under its shade, the odor being so strong as to occasion violent sneezing,” wrote English botanical explorer David Douglas in 1826.
The oil that these leaves produce has been used for treating headaches, colic, diarrhea and meningitis. On the other hand, some people report getting a headache after smelling this odor for several hours. No special concern about the wood’s dust has been reported however. There is a slight aroma to the dried wood.
Special note: The myrtle wood mentioned in the Bible in Isaiah is Myrtus communis, a different tree (genus and species) altogether.
Processing Suggestions and Characteristics
Although weighing over 50 pounds per cubic foot when first sawn, the wood, after drying to 7 percent MC, has a specific gravity of 0.57 or a density of 37 pounds per cubic foot. This is equivalent to 3 pounds per board foot, about as heavy as soft maple.
Oregon myrtle is tricky to dry without checking and warping. Very slow drying (slower than white oak) actually enhances the colors.
Shrinkage is drying is about 7 percent in the tangential direction (across the width of lumber in a flatsawn piece) and 2 percent in the radial direction (thickness of flatsawn lumber). This large difference between radial and tangential means a very high tendency to cup in flatsawn pieces of lumber sawn from near the center of the tree. The swirly grain also means a high risk of warping.
Gluing and Machining
Myrtle glues very easily and well.
Turners favor myrtle because of its tighter grain and ease of sanding. The swirly grain, however, will result in some tear-out when machining. The wood polishes very nicely with little effort.
The swirly grain, as well as the high tangential to radial shrinkage difference, means that some warping can be expected when the MC changes substantially. Otherwise, the wood is fairly stable.
Myrtle is considerably weaker than oak. The strength (MOR) of myrtle is 8000 psi, the stiffness (MOE) is 0.95 million psi, and hardness is 1270 pounds. For comparison, red oak has an MOE of 14,000 psi, MOE of 1.8 million psi and hardness of 1300 pounds.
Screws, staples and nails have reasonably good holding power.
Color and Grain
The key to developing premium color is how the wood is handled before it is dried. What is normally considered poor handling for hardwood logs and lumber will, with myrtle, develop outstanding colors and grain patterns. The tree also naturally has a lot of swirls in the grain. It is no wonder that this wood is often claimed as one of the finest woodworking species in North America.