This article, which appeared in the May/June 2008 issue of Sawmill & Woodlot Magazine, is part of S&W Publishing LLC’s “Tree Species” series and is not intended for reprint or republication. It is posted here with permission from Sawmill & Woodlot Magazine. To access copies of Sawmill & Woodlot’s “Tree Species” articles, visit http://sawmillmag.com/treespecies.php
THERE IS JUST ONE species of sassafras in North America, Sassafras albidum. It is most commonly found in the South, preferring humid, warmer climates. However, the tree does grow as far north as Maine and as far west as the Mississippi River. The tree can be quite small at times, but for sawmilling, trees that are 75 feet tall and 2 to 3 feet in diameter are ideal. Some trees are larger; these larger trees may be hundreds of years old and might be saved for the enjoyment of future generations. Sassafras is one of the few trees that are either male or female. It is also unusual in that one branch can have three different shaped leaves. A commonly found shape is mitten-shaped. In the fall, the tree shows off its beauty with red, orange, and yellow colors. Sassafras was considered special by the early European explorers in North America. In 1587, Sir Walter Raleigh brought the sassafras back to England from Virginia. In 1602 and 1603, ships were dispatched from England to collect the roots—the roots have a pungent odor that smells like root beer! Sassafras root tea was popular, but it is now known to be carcinogenic. These early sailing trips were called the Great Sassafras hunts. In Colonial America, sassafras was often used for bedsteads to ward off evil spirits and bedbugs. Sassafras shoots were boiled in water and then molasses was added to the resulting brew and the mixture was allowed to ferment, yielding (apparently) a wonderful beverage. Sassafras wood does have a high resistance to decay so is excellent for use in wet locations. Its light weight and decay resistance made it a popular choice by European settlers for fence posts and building forts.
PROCESSING suggestions and characteristics
DENSITY. Sassafras averages about 30 lbs. per cubic foot at 7% MC. This is roughly 2/3 as heavy as oak. A board foot, dried and planed, will weigh about 2 lbs. at 7% MC.
SAWING. This wood saws easily. To achieve the pleasant flatsawn grain, grade sawing is suggested. The market for thick lumber and cants is limited, so plan to saw this wood into mostly 4/4. Knotty pieces (that is, low grade) should be dried and then remanufactured into clearer, shorter pieces.
DRYING. Sassafras dries very easily. Slow drying can result in some sticker stain development. End coating is suggested. Shrinkage in drying is 5%. Final moisture contents for sassafras should be between 6% and 7% MC. Slightly higher MCs are tolerable, however, as when it is overdried the wood often becomes very brittle.
GLUING & MACHINING. Sassafras is easy to glue. Pressures must not be high as the wood is not extremely hard. Sassafras machines quite well with sharp tools. Dull tools can lead to fuzzy surfaces, especially if the wood is not at 7% MC or lower.
STABILITY. Sassafras is subject to small size changes when the MC changes—about 1% size change for each 6% MC change across the grain parallel to the rings (tangentially), and about 1% size change for each 7% MC change across the rings (radially).
STRENGTH. Sassafras is not exceptionally strong or stiff. The bending strength (MOR) averages 9,000 psi (2/3 of red oak). Hardness averages 630 lbs. (1/2 of red oak). Stiffness (MOE) averages 1.1 million psi (less than 2/3 of red oak). Sassafras often splits when nailed near the end of a piece. Predrilling nail and screw holes will eliminate this problem.
COLOR & GRAIN. Sassafras wood is pale brown and sometimes has a slight orange tint. The grain is coarse, due to the presence of large vessels in the early part of each annual ring. Overall it resembles ash in appearance. The wood has a faint spicy odor, somewhat like root beer and cinnamon. The odor is very faint when the wood is dry.
PESTS & DISEASES Unfortunately, sassafras has joined the rapidly growing ranks of North American tree species threatened by exotic invasive pests. In this case the new threat is another ambrosia beetle introduced from Asia, Xyleborus glabratus. In contrast to native ambrosia beetles, the recent arrival attacks vigorous as well as weakened hosts. Damage (sapwood tunneling) from the beetle alone is not necessarily a lethal problem. Rather, the wilt fungus (Ophiostoma sp.) that the beetle apparently introduces in its sapwood galleries eventually plugs the host tree’s plumbing, causing crown and tree death. Otherwise, sassafras’s pest problems are modest in scope and number. It is one of many hardwood species exhibiting varying susceptibility to Nectria canker (a stem target canker), verticillium wilt, and a variety of root-rot fungi. As for insect problems, stem damage and tree death, especially in younger individuals, can result from tunneling by the sassafras borer (a long-horned beetle), and sassafras foliage is a favorite food of two infamous exotic defoliators, the Japanese beetle and gypsy moth.
MARKETS. Markets are limited as very few people are looking for this wood. As its appearance is nearly identical to ash, it can be used as a substitute. The hobby market is certainly one outlet, especially for dry, planed lumber and 4/4 thickness is the best option. Due to its low strength and softness, it is not a premium wood for cabinets or furniture, but it is used occasionally. It does make interesting paneling, especially wainscoting; that is, the grain is not very heavy, but is still striking.
Gene Wenger is a Professor Emeritus at the University of Wisconsin-Madison and president of The Wood Doctor’s Rx. He can be reached at [email protected].
Eric Kruger is a professor in the Department of Forest Ecology & Management at the University of Wisconsin-Madison. He can be reached at [email protected].