Frothing Globe Willows

If your globe willows are frothing at the mouth or at least at the trunk it is >not because it is Halloween. The sweet frothy, smelly, sappy stuff coming out of >the tree trunk is slime flux or bacterial wetwood. > >Older book often talked about drilling holes and putting in drainage tubes or >other remedies but they are of no value. The insertion of a drain tube to >release the gas pressure is an old and discredited recommendation; it does such >more harm than good. If the dripping sap is causing problems on the lawn or >surfaces below the tree, wash the offending material with water. > >It is not possible to cure the problem, but it can be managed to some extent. It >is debilitating to the tree, so the minimize stresses imposed on the trees by >environmental and cultural factors. Don't let them suffer for lack of ater, >provide adequate fertilizer, and prune them properly. This means no popping or >extremely heavy pruning. Remove weak, damaged and dead branches. > >There are two types of slime flux in Utah, the heartwood type and dark/cambial >type. Each type needs to be discussed separately because the treatment is >different for each. > >The bacteria attacking heartwood result in the build-up of internal pressure up >to 60 pounds per square inch. This can burst the infected tree, but more often >the pressure forces the ooze out through cracks that extend from the eartwood >(inner portion) to the bark surface. Flux runs down the tree trunk, tilling the >bark tissue it contacts. It also drips to the ground where it kills grass or >other plants, leaving large, yellowish, dead areas. Trees are rarely filled with >this type of infection. > >There is no cure for the heartwood infection that is common in elms, >cottonwoods, and other poplar species. Drilling a hole in the infected area and >inserting a plastic pipe to drain off the ooze can relieve the internal >pressure. This prevents the unsightly slime from running down the trunk or >killing the grass, but does not eliminate the infection. > >Bark/cambial infections frequently result in death of the tree within 1-2"ears. >In willow, the bacteria tend to be limited to the tissue between the outer bark >and the wood called the cambium. Fermentation produces the offensive odor and >slime, but attempting to alleviate the problem by inserting a tube does not >relieve the problem. If the fluxing is noted soon enough, the tree can be saved. >Waiting and hoping the problem will correct itself often results in a dead tree. > >Trees with small bark/cambial infections may be saved by promptly cutting away >diseased tissue. Prune infected branches off at a lateral. With larger branches >or trunk infections, remove discolored bark down to the wood. In some bases this >means removing a lot of bark. If the infection encompasses more than half of the >trunk, it is probably best to treat with a chain saw at ground level and start >over with a less susceptible tree. > >Clean the wound with a disinfectant such as rubbing alcohol or a 10% solution of >bleach (1 part household bleach and 9 parts water). Watch the treated area for >evidence of recurring disease activity. If tissue on the edge of the ound >begins to flux, a spot of diseased tissue may have been missed. > > "Will the tree die?" Yes, but all trees die. Slime flux speeds its demise out >is not necessarily an immediate death threat. Keep the tree as long as it looks >good. When the care becomes too much trouble or the tree looks too bad, remove >the tree and replace it with another tree. Replace it with a flower-growing but >more resistant tree. Other trees subject to slime flux are mulberry, cottonwood, >ash and many of our other fast-growing trees. Larry A. Sagers >Regional Horticulturist >Utah State University >Thanksgiving Point Office >