Question
I live in Western Nevada (30 miles east of Reno) at 4200 feet.  I have a large Globe Willow tree that has some sort of disease.  The bark on several branches has split and sap is continuously dripping out.  It's a lot of sap.  In some places it appears that the sap is foaming out. The general consensus of opinion is that is bore worms.  Does this sound right?  My landscaper drilled holes to the roots and treated it with some stinky chemical.  It's not getting better.  In fact, more branches are oozing sap.  What should we do next?

Answer
Sounds like a disease called Frothy flux.

Frothy Flux is different from the Bacterial wetwood (slime flux) seen afflicting many other hardwood trees. Frothy flux  is contained to the layers of cells immediately adjacent to the cambium, while the true bacterial wet wood, found in elms, ash, hackberry and many other hardwood trees, is in the heartwood of the tree, deeply buried under many years of tissue. The term "froth flux" is used here to avoid any confusion that may occur with the true "slime flux" disease. Dr. Emroy Shannon, Extension Plant Pathologist, New Mexico State University, feels that "frothy flux" is not caused by a true pathogen, but is the result of a yeast or other saprophytic or secondary organism that invades the tree through a wound, causing the fermentation of the plant tissue.

Frothy Flux invades young as well as old trees, killing the cambium and contributing to the tree's death often within a few short years. The organism -- not yet positively identified by researchers at Colorado State University (or any other university to my knowledge) -- in addition to invading the tree through freeze injury, may gain entry through pruning wounds, insect damage, or mechanical injury caused by lawn mowers, weed whips, or other devices. Once gaining entrance to the cambium layer, the fermentation of the bark cambium and inner sapwood layers of the tree occurs. This results in a froth that exudes through cracks in the branches and trunk of the tree at the site of attack.

Larger, reasonably healthy trees seem to outgrow the problem. A weaker tree may have frothy flux for a year or two; the problem may seem to go away for a year or two; and then the problem reappears. Improving the health and vigor of the tree helps reduce the chances of the problem becoming severe.

There is not anything that can be sprayed on the trunk to stop this oozing. if You are careful and do not cut around the entire trunk you may want to try this.If it's not too pervasive, you can try cutting out the infected bark tissue. First mix up a bucket of 10% bleach water (one part bleach in nine parts water). Use a strong, sharp knife to cut out the infected bark. Dip the knife blade in the bleach water to disinfect it after every cut to prevent spreading the disease. Cut the bark down to hard wood. Be sure to cut out any discolored bark. Once you've got it down to the wood and all cleaned out, soak the open wound with the bleach water. At this point, leave the wound alone. Don't paint, cover or wrap it. Leave it open and exposed to the air. Dryness is your friend here. Keep an eye on the wound. If you get some foaming ooze at the edge of the wound, just repeat the process.

You don't want to remove more than one half of the circumference of the bark on a stem when you're cutting out the bark. Cutting off more than that will do more harm than good. If the infection requires you to cut off more than half, you're better off to remove the branch completely, or just leave the tree alone to fend for itself. Actually, I've seen willow and frothy flux sort of coexist for years. The disease never really goes away, it just fades in and out of the picture. The important thing is to keep your tree as healthy and happy as you know how to make it. Water the tree deeply, but don't keep it wet all the time. We tend to think that Willows need lots and lots of water, but they withstand drought much better than we give them credit for. Let the soil dry slightly several inches down, and then soak it deeply again. Fertilizer is okay, just don't overdo it. Too much fertilizer can result in lank, weak, disease-prone growth. Hope all this helps.


I would make sure the tree has water at least 1 inch per week and fertilize the tree. You might consider something like Miracle-Grow or Peter's, and even lawn fertilizer that is high in nitrogen.