Pine Gall Rusts in Various Stages of Use
One day a few summers ago, I was walking my dog in the park and we came across a pile of dead pine branches with these interesting and weird looking growths on them. Always on the lookout for carving material, I picked up a branch and broke off the dead wood around the growth so I could take it home. I did some research and discovered that it was a pine gall rust.
Endocronartium harknessii is the scientific name for the fungus responsible for this disease. As the fungus grows into a sphere around the branch, it cuts off the supply of sap to the outer part of the branch, thus killing the branch beyond it. Because the fungal spores are airborne, several branches in one tree can be infected, and many trees in one stand can be infected. Removal of the infected branch or tree is the best treatment.
I returned to the park with a bucket and brought some more home. I thoroughly cleaned each gall, then left them in my garage to dry out a bit. Weeks later I came across them again. I attempted to carve into one, but found the material to be too hard for my liking. I decided that they would make interesting bases for my carvings though.
What I have learned over the past few years is that they are very resinous. Because of this, they can gum up saw blades and sanding disks, and they are good for starting campfires. It is best to let them dry for several months before sanding or cutting. I hang them from the rafters in the garage in mesh onion bags. After cutting, I like to let them hang to dry for another couple of months before finishing.
I love the look after cutting them into slabs/disks, and sanding and finishing them. They set off my miniatures nicely and make great ornaments.
For more easy to read information, check out this Cornell University Fact-sheet.
Next time, we will talk about mistakes…