Gummosis on a peach tree. Gummosis on a Peach Tree

Gumming on a peach branch.
Gumming on a Peach Branch


  • All stone fruits


Gummosis is a general term describing the prolific oozing of sap from a tree. Stone fruit trees are sensitive to injury, and will respond by exuding a gelatin-like gum in spring. Gumming is produced due to a variety of factors, including borers, diseases, or wounding. It can also be a response to poor growing conditions, such as compacted soil. If the oozing gum is clear, the problem is abiotic (non-living). If the ooze is milky or dark-colored, it may be caused by an insect or disease.


See Cytospora/Perennial Canker if a disease is suspected.


  • Gelatinous-like ooze on bark that is clear, milky, or amber colored.


Where possible, prune out areas that have ooze. Where ooze is clear, there is little concern. If ooze is dark-colored, contact the Utah Plant Pest Diagnostic Lab for a diagnosis.


Inspect limbs and trunk during regular pruning practices and periodically over the summer.

Precautionary Statement: Utah State University and its employees are not responsible for the use, misuse, or damage caused by application or misapplication of products or information mentioned in this document. All pesticides are labeled with ingredients, instructions, and risks, and not all are registered for edible crops. “Restricted use” pesticides may only be applied by a licensed applicator. The pesticide applicator is legally responsible for proper use. USU makes no endorsement of the products listed in this publication.