In the garden: Burls are unexplained, and best left alone

Scott Eckert
Special to The Newton Kansan
On occasion trees can develop some unwanted growths that were not on them when planted.  One of these strange growths is called a “burl.”

Homeowners are proud of the landscapes they create around their homes so they can enjoy the beauty of their surroundings. You can do everything correctly like pruning and fertilizing but on occasion trees can develop some unwanted growths that were not on them when planted. One of these strange growths is called a burl.

Burls are hard, woody protuberances that grow on the roots, trunk or branches of nearly every tree species. 

The cause of most burls cannot be explained though they may develop as a result of insects, bacteria, fungi or environmental injury, such as freeze damage.

Their growth is chaotic, and they feature irregular grain patterns that do not match the grain of the rest of the tree. As years go by and the tree grows, the burls continue to grow as well. They can span from several inches to several feet across.

They do not harm the tree directly, but there is some scientific evidence that burls make a tree more susceptible to insects and disease.

Sprouts arising from the burl may be pruned off; otherwise, no treatment is necessary.

Removal of the burl may damage the tree and is not recommended.

Burls are hard, woody protuberances that grow on the roots, trunk or branches of nearly every tree species.
Scott Eckert

— Scott Eckert is a Kansas State Research and Extension agent for Harvey County. Horticulture is his specialty. He can be reached at 316-284-6930.