How to Harvest and Sell Burls

I get a lot of responses to my website from people who have burls and want to sell them. Here's the advice I usually give them.

First, do some careful measuring of the burl and be able to describe it well when you make contact with someone.  A few photos would be helpful, especially if you have a ruler or yardstick as a size reference.  If the bark is gone it's probably rotten and not worth much.  A big factor for me if I am looking for or buying burls is if they are an "eyed burl"  or a "layered burl." Here is some information to help you figure that out, but if you can't, just tell your seller you are not sure if it's a layered or eyed burl

A large oak layered burl. You can see this is a layered burl because the shape is rather random and not circular. Note cutting a bit above the burl to protect the burl from splitting.

A layered burl is the result of an injury to the tree.  That might be a frost split (caused by a sharp frost when the sap is already running), very common on maples, physical damage done the tree or a broken off branch that the tree grows over to protect itself.  The layers are the way the tree protects itself from further damage by sealing off the hole in the tree's bark. The shape of a layered burl tends to be rather random, and not rounded like an eyed burl

The more valuable burl is called an "eyed burl," or a basal burl, and it is really a tumor on the tree.  An eyed burl can usually be identified by the round or dome-like shape it makes on the outside of the tree.  Note that the burl can be made up of multiple round shapes stacked close to and overlapping each other but the basic building block shape is still round.  Once you cut open the eyed bur, you can see that they have eyes- a kind of bird’s eye where the burl growths

I understand that is true because the eyed burl develops from a very small burl earlier in the tree's life which grows larger but still radiates symmetrically each year as the tree grows in diameter. I observe that the burl wood from a larger burl on a smaller tree is more dense, uniform and of higher quality than the same size burl on a larger tree.  The ultimate I have found are "ball burls" which are like a 'tootsie roll pop" on a stick.   To harvest those, definitely leave 6-8 inches of wood on both ends of the burl to protect it from cracking.

This is a Boxelder eyed burl built up of many rounded shapes. It's tricky to keep your saw sharp cutting so close to the ground, but worth it for good burl. Use a wire brush to clean off all the dirt you can and be prepared to sharpen your chain saw blade often. Some people think all burls are root burls, which is not correct. Most burls are higher up on the tree.

To harvest a burl, it's best to harvest the whole tree.  That's because most of the burl is inside the tree, often reaching all the way to the center or pith.  To cut the burl off even with the outside of the tree, which I call a "cow pie" or a burl cap is both wasteful and damaging to the tree's health.  When someone offers me "cow pies" I assume they were poached (cut without permission) and I am very hesitant to buy them.   I prefer to wait until the tree has reached maturity and cut down the whole tree.  Then the best way to harvest them is to leave some normal wood on either side of the burl, maybe 6-8 inches, to avoid cracks in the burl itself.

Cutting a black ash burl into sections. I try to cut on natural fault lines in the burl. Using round cardboard circles helps me visualize bowl blanks from the burl.

If you absolutely need to cut up the burl, you risk losing lots of its value.  If you can, let the buyer supervise the cutting up of the burl into smaller pieces. That might be necessary if you don’t have a way to move or haul the full burl.  If you need to cut it, look carefully at the burl and look for "fault lines" in the burl.  In eyed burls they are  formed when smaller burls around the tree push up against each other and form a defined boundary between them, often with bark included.  At least for bowl stock, I generally would try to cut from the outside of the tree directly toward the pith of the tree.  That could be either vertically or horizontally.  I often use various sizes of cardboard discs to lay out the best use of the burl.  Once you’ve cut the burl, you should coat the cut surfaces with an end grain sealer to keep them from cracking and then get them out of the sun as soon as possible. Either buy some end grain sealer at a woodworking supply store or catalog, or use something like Elmer’s wood glue to paint on the surface. Paint is not worth your trouble. Covering it with a tarp will help somewhat, canvas would be better than plastic, and make sure it can breathe around the outside edge of the tarp so it doesn’t trap all moisture inside. Then it will “spalt” and discolor, or maybe that’s the effect you want.

Here is a Boxelder burl cut up for transport. For best quality, haul and store it in one piece if you possibly can.

Burls of Black ash, boxelder, and cherry turned into bowls and hollow vessels.

Most of the hundred bowls from one huge Black ash burl, and a bit of the burl that remains to be cut up.

If the burl will be used for slabs instead, you will have to visualize how the slab will be cut out of the burl and cut accordingly. If you’re cutting for table top slabs, you must not cut at a right angle to the trunk, though that may seem the obvious way. A slab that includes the pith of the tree will definitely crack. Instead, cut the burl lengthwise to the tree’s growth, straight up and down if the tree were still standing. That is the most likely way to keep the slabs from splitting. For slabs, I much prefer to have a sawmill cut my slabs, but you may need to make your first cut lengthwise along and through the pith to get pieces you can handle.

Now, as to finding a buyer, I'm partial to woodturners and they tend to be good customers for burls.  To find them, Google "woodturner" along with the name of your town or nearby larger city.  You are likely to find a listing for woodturners who sell their bowls and likely buy burls or know who would be interested.  If there is a specialty woodworking shop in your area, like Woodcraft, check with them.  The staff there tend to know who would buy burls or will perhaps post a notice on their bulletin board.

If that doesn't work, then you should go to the American Association of Woodturners website,  http://www.woodturner.org/  In the "Find a Chapter" section under "About," fill in your state to find nearby chapters.  There are about 400 of them so there should be one relatively close.  There you should find a website link or the email of an officer.  Contact them and ask who they could contact about selling a burl. Include several photos if you can.

For example, I found from my Google search a  good resource directory for Minnesota at the site http://files.dnr.state.mn.us/forestry/um/sfp_htm_directory.pdf   It has lists and information for both harvesters and sellers and for buyers of burls and other forest products like diamond willow, crotch and other specialty wood.

Finally, don't have unrealistic expectations about the price.  Most burls, especially layered burls, are not particularly valuable.  On the other hand, a larger eyed burl in good condition should bring $25 to $200 depending on size, species and condition.  I have had burls up to 8 feet in diameter, and many in the 4-5 foot range. Those can be worth $500 or more if they are sound and not rotten.  It may be worth it to seek more than one offer on your burl if you think it is particularly valuable. If you have access to many burls, it would be worth your time to cultivate relationships with woodturners or slab table makers. Use the information above to find them, set up a time to visit with them, and learn all you can from them about what they are looking for. A woodturning club meeting would be a total revelation to you as to all the ways to use burls. You may want to bring some burls there and sell them right there.