What Is Burl?
I have discovered that this question is the most searched question for burls on the internet. Over 140,000 times world wide per month.
So I read what Wikipedia’s definition is and found out that they are not clear and in some details are wrong in their definition. So I am going to attempt to clear the muddy waters.
First of all Wikipedia says: “A burl (American English) or bur or burr (used in all non-US English speaking countries) is a tree growth in which the grain has grown in a deformed manner. TRUE It is commonly found in the form of a rounded outgrowth on a tree trunk or branch that is filled with small knots from dormant buds. False A burl results from a tree undergoing some form of stress. TRUE It may be caused by an injury, virus or fungus. AND I WOULD ADD iNJURY DUE TO FIRE, BUG, TREE RUBBING EVEN WEED WHACkERS ETC. 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. FALSE AT LEASE IN THE AREAS I HAVE SEEN. Such burls sometimes appear as groups of bulbous protrusions connected by a system of rope-like roots. THIS HAPPENS SOMETIME.I HAVE SEEN IT IN MANZANITA BURL 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.” ONCE AGAIN NOT IN MY EXPERIENCE.
So here is my definition of a “What is burl”:
A burl is a growth on or at the base of the tree and sometimes under the ground that is due to damage to the tree. The tree started to heal itself and forgets to stop healing.
Burls are not always formed because of the injury. You can see an example from a branch being pruned off. When a branch is healed over in my opinion, is not a burl which is commonly mistaken. Yes it has some figure in it but not as a burl would have.
I have seen what I call “Sucker Burls” in box elder where there is multiple buds growing in the burl which makes for an additional niceness in the figure and color.
You have different kinds of burl
• Pen Burl
o Tubes that grow from the point of injury out
o Lace figure that frames the tubes
• Swirl burl
o Figure is in a swirly patter but no “pen”
o Another name “Konk” or “Bunion”
• Root Burl
o Grows under the ground sometimes deep as a big onion
o Grows on the root itself
o Both for the most part are pin burl
o You will always have good figure in root systems due to the compression in the corners of root.
I did forget to mention the Cluster log. which is burls all the way up the tree in clusters.
Don’t mistake figure in the wood for burling. That is another article for a later time.
Would love your insight and comments.
-- Greg, Southern Oregon, www.oregonburls.com What can I say but God Is Good!