Bacterial wetwood or slime flux, is a common disease that affects many hardwood trees. Wetwood is common on elm, cottonwood, aspen and willow, although it may also affect ash, fir, maple, apple and others.
To identify wetwood, look for a yellow-brown discoloration on the trunk or branches. The area of infection is moist and periodically has foul smelling sap oozing from the tree's central core where the problem originates. Fresh ooze is attractive to yeast fungi and insects. Dried ooze has an ashen-gray appearance. The dripping wetwood slime is toxic to the tree's cambium, (tissue that produces new cells) and is also is lethal to other plant foliage, young shoots and grass.
For more details please refer to PlantTalk script "Bacterial wetwood" and the eXtension article "Slime Flux".
