Bacterial Burls on Monkey Puzzle Tree: Harmless but Fascinating

What Are Those Growths?

The unusual, resin-oozing growths at the base of your monkey puzzle tree (Araucaria araucana) are bacterial burls. They form when bacteria (or sometimes viruses/fungi) irritate the bark, triggering abnormal wood growth. The bacteria stimulate rapid, disorganized cell division, creating the knobby, figured wood prized by woodworkers.

Impact on Tree Health

• No structural weakness: Burls do not compromise the tree's stability.
• No disease spread: The bacteria do not infect other trees.
• No treatment needed: Removing burls creates large wounds that invite decay. Leave them alone.

What to Expect

The white resin is a natural response. Some crown dieback may be normal seasonal shedding. Monitor for signs of other issues (fungal conks, extensive deadwood), but the burls themselves are a benign, lifelong feature. Enjoy the unique character they add—woodturners would love them!