Ask An Arborist: October 29, 2009

Slime Flux on Hardwoods

Image 1 Submitted by John Image 2 Submitted by John

John in Roswell Writes...

Our red oak developed a seep near the base of the trunk in late spring. Recently, another small seep has developed (photos above). We want to know if this condition is something we should be concerned about and, if so, what remedial measures can be taken to protect the health of this tree.

And The Answer Is...

Slime flux, also known as Bacterial Wet Wood is an infection that is common to many hardwoods, especially oaks and tulip poplars. The wound is characterized by an oozing or wet appearance that is dark and often foul-smelling. Bubbling or foaming may also be seen at the infection site. Sap in the infected area is fermented by the bacteria which also causes carbon dioxide gas the build up in the affected tissue. The nearby bark cracks and peels away from the area. Often, insects such as flies, bees and occasionally butterflies will gather to drink the fermented oozing sap. I have seen insects become intoxicated on the "brew."

The bacteria responsible are commonly found in the environment and are native to North America. They enter through wounds in the tree which can be caused by mechanical injuries (lawnmowers, weed whackers, etc.) or where limbs have broken out of the tree and so forth. Stress can leave trees susceptible to slime flux. Always avoid injuring tree trunks with equipment by maintaining a mulched bed around the base of all trees. Properly prune limbs so that the tree is able to seal off the wounds and reduce the risks of infection.

Fortunately, slime flux is rarely fatal to otherwise healthy trees. Do not attempt to apply anything to seal the wound but you can remove any damaged bark with sharp pruners. Usually the wounds heal on their own after several weeks, but it can take up to several months.

Trees suffering with slime flux should be kept as healthy as possible. Make sure that there is ample organic mulch (2-3 inches) over the root zone preferably extending out as far as the branches. During times of drought, water deeply 1-2 times per week. Apply a slow release fertilizer in mid spring. If your tree is growing in compacted soil, you may want to hire a tree professional to aerate the root zone with the proper equipment.

For more information on slime flux, you may want to read these articles:

North Carolina State University
Iowa State University

If you are concerned about the trees in your landscape, you can contact a Certified Arborist or a professional tree company in your area through the web site of the Georgia Arborist Association.

If you have comments or questions about this article or want to submit a question that may be used in a future article, please email me.

Unless otherwise noted, Images & Drawings Copyrighted © 2009 by Theresa Schrum - All rights reserved