OneStop | Directories | Search U of M 

CUES: Center for Urban Ecology and Sustainability

Table: Diagnosis and Control of Bacterial Wetwood
Pest Identification Host Plants Damage Symptoms
Bacterial Wetwood of Elm
Erwinia nimipressuralis, and other anaerobic bacteria
Elm, oak, and other hardwoods. The bark of infected trees appears brownish to gray in color. The discoloration of the bark is the result of bacteria oozing out of the tree. Bacterial ooze is usually associated with some type of wound. Bacterial ooze may smell foul.
Monitoring Control Options Pesticides
This disease does not need to be monitored. Elm trees appear to be predisposed to infection, while other hosts appear to be affected by site quality and tree vigor. There are no control options. Do not insert pipes into the tree to help the tree drain. None
Description and Life History
Description: Wetwood is caused by a bacterium that utilizes carbohydrates (not cellulose) in the heartwood of the tree.

Life history: Bacteria enter trees through wounds. Once inside, the bacteria multiply and begin to produce ooze, which flows out of wounds. Bacteria may be dispersed through rain splash and wind.

Overwintering: Bacteria overwinter in the heartwood of the tree.


Back to Diseases of Deciduous Trees


(C) Regents of the University of Minnesota. All rights reserved.
The University of Minnesota is an equal opportunity educator and employer.

Contact U of M | Privacy
Last modified on March 07, 2013