UACES Facebook Wet Wood/Slime Flux
skip to main content

Wet Wood/Slime Flux

(October 2008)

QuestionI have a sugar maple, ‘Autumn Blaze’ about five years old in my front yard facing the south. It is at least 10 to 15 feet tall.  I recently noticed an area close to the bottom of the tree about 7 or 8 inches from the ground that is bleeding a black substance.  Is this usual or should I be concerned?


AnswerOne of two things can be happening.  Maples are notorious for “bleeding” sap from any wound.  If something wounded the tree such as a weed eater or lawn mower, this could simply be the case and is nothing to worry about.  The other scenario could be wetwood or slime flux, which is caused by a bacteria.   Gasses and liquid by-products of the bacteria cause the internal pressure of the sap to increase, forcing the liquid to ooze out any opening along the tree. It tends to have a sour or fermented smell to it and is quite attractive to insects. It can be dark in color or white and foamy.  While it doesn’t signal imminent death, it does tell you the tree is stressed.  Keep the tree as healthy as possible with regular watering.  Try to use your garden hose to remove the sap from the trunk of the tree as the fermented sap can be damaging to the trunk of your tree if left there.  This problem is usually more common during spring and summer.

 All links to external sites open in a new window. You may return to the University of Arkansas System Division of Agriculture web site by closing this window when you are finished. We do not guarantee the accuracy of the information, or the accessibility for people with disabilities listed at any external site.

Links to commercial sites are provided for information and convenience only. Inclusion of sites does not imply University of Arkansas System Division of Agriculture's approval of their product or service to the exclusion of others that may be similar, nor does it guarantee or warrant the standard of the products or service offered.

The mention of any commercial product in this web site does not imply its endorsement by the University of Arkansas System Division of Agriculture over other products not named, nor does the omission imply that they are not satisfactory.