Bacterial Wetwood (Slime Flux)
Erwinia nimipressuralis

Curtis E. Swift, Ph.D.
Area Extension Agent (Horticulture)
Colorado State University Extension

Wet Wood oozing from an old pruning cut

Wetwood, also called Slime Flux is caused by the bacterium Erwinia nimipressuralis among others. This organism causes the fermentation of plant tissues deep within the trunk. The resulting pressure (up to sixty pounds per square inch) usually forces the bacterial ooze out cracks, branch stubs and pruning cuts but can cause tree to burst open. As the ooze runs down the branch or trunk it discolors the bark. Previous recommendations for correcting this problem included drilling a hole in the tree to relieve the pressure. We now know that this causes further damage by spreading the disease organism, resulting in increased infections. At this time there is no `cure' for the problem.

The slime drips from branch cuts high in the tree

As the pressure builds up in the tree, the slime may drip from branch cuts high in the tree. This alcohol-based ooze kills the cambium tissue near the cut preventing the proper callusing of wounds. The ooze kills grass and other plants upon which the slime drips.

Further information is available at Bacterial Wetwood

Placed on Internet April 15, 1996
Updated on July 26, 2010