Okay I'll post it here since I no longer seem to be allowed to use the Pest Identification forum (which was the most valuable forum here, imho). I have a black locust tree, at least I am pretty sure that is what it is.... two of them actually which came up volunteer along the fence about 10 years ago. They grew pretty fast, and are now quite tall- trimmed them high above the power wires so they make kind of a canopy. All that is fine. What is not fine, is that one of them has developed the most perplexing of problems. And it couldn't be happening in the worst spot. The tree has a pronounced lean, and leans over the neighbors house. I decided this year that maybe I should take the tree out- so then I called a tree cutter who assured me that 1) taking out the tree would be an astounding $1200.00, and that was probably the best price in town and 2) this type of tree practically never falls over, they are very solid and not to worry about it falling over. So I decided to leave it. Then something very weird happened. It seems like the bark is moving away from the tree, on the front side at the base. Or the wood inside is melting away. Or something. It looks normal, but you can push the bark in about an inch. I don't want to rip the bark off to see what is there exactly, because of course then there will be a big gaping bare spot. Attached are pictures. I don't see any bugs except there were some very small ants on the tree, after which I put ant poison in the area and they seem to have disappeared. Does anybody have any idea what might be going on here? Fearing the worst of course but I don't have any idea really what to do. Thanks much for any input. :/ http://oi58.tinypic.com/2zf64ps.jpg http://oi61.tinypic.com/o870xu.jpg http://oi61.tinypic.com/jj8k1x.jpg The pictures are a bit misleading. It looks a lot less noticeable from further back: http://oi61.tinypic.com/r7lvtt.jpg The whole tree. http://oi57.tinypic.com/288waiq.jpg
Two other things I want to point out in the pics: 1- Note the wood 'shavings', that look like toothpics on the bark. That was stuff inside the tree that I brushed out, leaving the hollow area under the bark. It looks white like bone in there. 2- That round root. A friend came by and suggested that could be another tree growing up inside the first tree, pushing the bark away. (???) Seems a bit fantastic but thought I'd mention it. I just figured it was part of the tree itself.
Something killed the cambium layer on one side of the tree several years ago. If it is on the south side of the tree, sunscald is a possibility; or the base of the tree could have been damaged somehow. Anyway, something killed the cambium layer under the bark that feels hollow underneath; and the heartwood started to rot, all hidden by the thick layer of bark on the surface. Since that happened, the living cambium layer on both sides of the dead area has been regrowing, trying to cover the damaged part. As it grows, it thickens and lifts the bark above it, leaving the hollow space that you mentioned. What you described as a root is the newly regrown cambium, now several years old. You should be able to find something similar on the other side of the dead area, probably still hidden by old bark. Since the heartwood is obviously decaying from fungal action, the tree trunk is already weak and will only get worse. In your situation that tree has to be removed. You can see a similar situation, but more obviously visible, in the nearby thread titled "Help! Large amount of bark peeling away"
why can't I treat the fungus? The tree is regrowing over the damaged part and the wood underneath seems solid enough.
The wood looks pretty rotten in the first picture, but it's difficult to tell how bad it is. You should remove all of the loose bark to determine the extent of the damaged area. Leaving the bark there just encourages rotting of the wood underneath because it traps moisture under the bark. If any of the interior wood is soft and rotted, then you can expect the whole interior to rot eventually. The fungus will have spread far beyond the visibly affected area, and I don't think that treatment will be effective. However, the best thing to do is to have it inspected by a certified arborist, who will determine the best course of action.
