Selecting a White Oak Tree for Basketry
Finding the right tree is not easy, but time spent locating a good one pays off when the splitting begins. The best tree for splints is found in hollows, in rich bottomland soil or the lower part of a north or east slope. They are most often found with hickories or other oaks in a mature forest. Look for trees as close as possible to your vehicle. It is not unusual to walk for a long time in search of a usable tree, but keep in mind that the log will have to be carried out. Sometimes a log will have to be split in half before being carried out. Having your vehicle near and having the knowledge to make a maul and gluts should comfort you.
This instructional is excerpted from Jan Henry’s book Handling White Oak, which can be purchased at whiteoakbasketry.com.
Which Tree to Harvest
Trees from 4” to 10” may be successfully split, but a beginner should take a smaller tree (4”-6”) since there is less effort involved in processing a smaller tree and it’s easier to fell. Look for a tree with straight, smooth (but flaky) light gray bark and no visible knots or blemishes. A hand run over the bark will cause flakes to come off a good tree. Pass by any with twisted bark, obvious knots or burrs, low branches, or signs of disease or insect damage.
A small knot on only one side can be worked around if nothing better can be found. A tree that stands straight will be better than one that leans. A tree that leans will have reaction wood on the upper side that is in tension as it pulls the trunk upward. This causes it to twist, dry unevenly, and shrink lengthwise.
The white oak tree puts on a layer of cells each year of its life. These are annual growth rings and appear as concentric circles on the cut end of a log (see fig. 1-3). Upon closer study of this cross-section of a log’s end we see a dark center surrounded by a lighter area near the bark.
The dark portion is heartwood and the lighter portion is sapwood. Heartwood was once sapwood but has become inert and only functions as tree support and as a reservoir for tannin and other chemicals. Knots are the remains of limbs and originate in the pith at the center of the heartwood. The wood surrounding knots is usually distorted.
The sapwood is composed of long, hollow fibers made of cellulose, which are vessels for transporting water and nutrients to and from the roots and leaves.
During favorable growth conditions the layers will be thicker than in times of drought. In early spring these fibers are large and weak. This layer is referred to as earlywood and appears as a dark line. The wood will split easily at this weak layer. Later, in late spring and summer, cells become smaller and stronger and are called latewood. This layer appears as a wider and lighter-colored line, and is the layer that is woven into baskets. The concentric circles are considered in the tangential plane and wood is split tangentially (with the layers) to achieve thickness.
Also visible on this cross-section are the rays. Ray cells are wide flat plates that radiate from the center of the log and cross the growth rings at a right angle. This is where checking occurs. Checking is a split in the wood caused by loss of moisture.
The direction the rays lie is called the radial plane and wood is split radially (perpendicular to the rings) to achieve width.
The remaining component of our cut log end is the bark and the thin layers just under it. The cambium lies between the sapwood and bark and supplies cells to both. In the spring and summer the cambium layer becomes active and splits off rows of wood cells to the inside and bark cells to the outside. Cells toward the wood tend to collect while bark tends to shed old cells. In the bast (soft inner bark) are sieve tubes through which sugar, formed by the leaves during photosynthesis, travels to be stored in the roots and stems. During warmer months, this layer is moist and the bark peels off easily.
The outer layer, generally referred to as bark, is rough and thick and offers protection for the tree. These outer layers are all removed during the splitting process.
All parts of a basket are made with wood that is split with the grain. The grain is the direction in which the fibers or vessels of the wood lie. Wood split with the grain is stronger than sawn wood.