Slime Flux

One of the strangest questions I get as a horticulturist goes like this, "My trees seem to have foam like shaving cream or soap suds coming out of cracks in the bark." This is not a typical plant disease symptom and some gardeners are reluctant to even ask such a question because they fear someone will question their eyesight, their sanity, or both. Trees are not supposed to produce foam or soap suds. This symptom is from a bacterial disease called bacterial wetweed or slime flux. Infections cause wet, gray-brown area on limbs and trunks. The slime from the infection runs down to the bark, discolors the plant tissue and results in a build up of dry, unsightly scum. The oozing material has a putrid smell and can damage surrounding plants. The ooze drips onto the the lawn or other plants below, resulting in dead or discolored spots. Bacteria enter through wounds in the bark from improper pruning, boring insects, poor branch angles, lawn mowers, or weed eaters. Healthy, intact bark is an excellent barrier, much as your skin is to you. Susceptible trees include elm, cottonwood, poplar, boxelder, Russian olive, ash, mountain ash, aspens, poplars, fruitless mulberry, and with the "Globe" or "Navaho" willow being the most commonly affected. Insects like worms, maggots, beetles, flies or wasps are looking for a free drink of the sweet fermented liquid that occurs when the bacteria ferments the sugary sap of the tree. Next time you see your trees oozing or frothing at the bark, don't question your sanity. Disinfect the wound with rubbing alcohol or a 10% bleach solution(one part household bleach and nine parts water). Prompt treatment may save some trees, but the disease must often run its course and the tree will either live or die, depending on the extent of the infection. Hopefully yours will be spared this affliction.