What Are Tree Burls?

Date April 06, 2023

Author TreeNewal Staff

Tree burls are bumps, bulges, or growths found on the trunk or root system of trees. While often unsightly, they generally cause little harm to the tree. These growths come in a wide variety of shapes and sizes that may have deep ridges and lumps. Find out about the impact tree burls may have on trees in the Dallas-Fort Worth, Texas, area.

What Causes Tree Burls?

Image via Flickr by Plant pests and diseases

Arborists don’t have a definitive answer why some trees grow burls. They speculate that the tree will grow a burl when it’s been stressed, either from an injury or from an infestation from pests or diseases. The tree bark cells grow abnormally, causing the rounded irregular growth known as a burl.

Are Tree Burls Dangerous to Trees?

Some people mistake galls for tree burls, but they are pretty different. A tree gall results from an insect or fungal infestation and may cause harm to the tree as the pests feed on the host plant. Tree burls, on the other hand, are benign growths that cause no harm to the tree.
If a burl forms in response to an injury to the tree, the hard, woody nature of the burl will wrap around the wound and protect the tree from further damage. Depending on where the burl grows, it may restrict the vascular growth of the tree. While this scenario is rare, a professional arborist can help.

Do Tree Burls Need To Be Removed?

It’s unnecessary to remove a burl from a tree unless the homeowner is unhappy with the sight of it. Removing tree burls can create a large wound that the tree will need to recover from, and the healing process may cause more stress for the tree, potentially weakening it. Woodworkers prize the unique grain of tree burls and use the burls to make bowls, cutting boards, and furniture. However, removing a burl for woodwork requires special care, and woodworkers should only purchase burls from a company that can remove them safely from a living tree or from downed trees.

Are There Ways To Prevent Tree Burls From Forming or Growing?

Keeping trees healthy is the best way to prevent tree burls from forming. A professional ISA-certified arborist can analyze the tree’s soil nutrient content and make recommendations on fertilization applications to boost the nutritional value of the soil. In addition, they will check for pests, insects, fungi, or diseases that can have a negative impact on the tree, which may cause the tree to grow burls. Burls rarely cause harm to the tree, but if new growth sprouts from the burl, the arborist will need to prune the growth back to keep the tree healthy with sound structural integrity.

TreeNewal is one of the Dallas-Fort Worth area’s premier tree-care service companies. We specialize in soil nutrition to help keep trees healthy as well as various types of pruning to keep trees shapely and healthy. Call today at 817-533-8438 or contact us to discuss your North Texas tree-care needs.