I have a 4 year-old weeping willow that has been (apparently) completely healthy and growing very rapidly and fully until about a week ago. At that time I noticed that the leaves on the left side of the tree off of one main-trunk branch had gone brown, while the leaves on the right side were showing normal signs of late-mid summer yellowing. This morning I did an inspection of the tree up close and found that the trunk bark from the ground up to about 3 feet off the ground had largely separated and peeled away from the wood and that there was a very large “clump”? of what looked like hair attached to the underside of the peeled bark and to the wood. On further examination, it looked very much like tiny parasitic veins that had attached themselves to the trunk. I had to work very hard to pull this clump off. I also noticed several light yellow “pods” about an inch long that looked like medicine capsules attached to the trunk as well. Are they related problems? I peeled all the “infected” and separated bark off and got as much of the “veins” off as well. Is this a fungal infection? I can’t seem to see anything online that looks like this problem. Most importantly: Can this be cured? Do I need to wrap that naked section of trunk now? Any help would be appreciated!
In suspicious that your willow has picked up some type of borer that is hollowing out the layer under the bark. If the bark has come off all the way around the trunk, then it won’t recover. If there is still bark adhered to the trunk then there is hope for recovery if the borers are killed. Borers are difficult to control by spraying so a systemic will be the way to go. I’d suggest Bonide Annual Tree and Shrub Insect Control. This is mixed with some water and then soaked gently into the soil at the base of the tree. Dosage and use instructions are on the jug. Read and follow the directions and do it soon while the tree is actively growing.