The Beauty of Burl Wood February 22 2015
A burl results from a tree undergoing some form of stress. It may be caused by an injury, virus or fungus. Most burls grow beneath the ground, attached to the roots as a type of malignancy that is generally not discovered until the tree dies or falls over. Such burls sometimes appear as groups of bulbous protrusions connected by a system of roe-like roots. Almost all burl wood is covered by bark, even if it is underground. Insect infestation and certain types of mold infestation are the most common causes of this condition.
In some tree species,burls can grow to great size. The largest, at 26 ft (7.9 m), occur in coast redwoods (Sequoia) and can encircle the entire trunk; when moisture is present, these burls can grow new redwood trees.
Burls yield a very peculiar and highly figured wood, prized for its beauty and rarity. Burl wood is very hard to work with hand tools because its grain is twisted and interlocked, causing it to chip and shatter unpredictably. This "wild grain" makes burl wood extremely dense and resistant to splitting.
Many burls resemble an explosion in which the grain grows erratically and these spectacular patterns enhance the beauty of the wood.