Question
My older globe willow has the following symptoms:  1) shedding of outer bark, mostly on trunk and large branches. 2) Sweet smell and oozing/dripping of clear/white sappy liquid at one of the branch joints and all down the trunk, which is attracting flies.  Is this the dreaded honeydew secreted from giant aphids eating my tree?  I didn't notice any giant aphids, but a ladybug landed on me while I was inspecting tree and I know they eat aphids.  I live in southern New Mexico.  What is this and how can I treat it?  Thank you! (P.S. I can upload a pic if necessary)

Answer
Sounds like a condition called Froth Flux. Honeydew will be on the foliage and under the tree on the grass and be very sticky.

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 with stand 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. Fertilize the tree with 10-10-10 fertilizer at the rate of 1 lb of fertilizer per inch of trunk diameter scattered around the tree and watered in good. Water-Place a pan under the tree and turn the sprinkler on and when the pan has 1 inch of water in it stop.