Japanese Maple 50 yr old
I noticed something affecting the tree a few years ago. I called a local arborist to look at it, as well as to trim it. He said there was nothing wrong with it. The bark was split from bottom up to about 2.5 feet. The branches were dying off. I noticed the top of the tree branch is now dead and a few other outer small limbs are dead. Also, I had trimmed/cut off a dead limb last year, and I noticed recently there were carpenter ants nesting. I did read they only eat into dead/diseased wood. I flushed them out. I called another arborist to look at the tree. He said it had canker. He could inject the fungicide in, which may turn the tree green and that the tree has a 50/50 chance of living and he would fertilize for $250. I had called the 1st arborist the other day stating my concern of him 'missing' the fact the tree was dying. The 1st arborist came today and said, the tree has Verticillium Wilt. He said there was nothing to do to save the tree. This tree has sentimental value. I've read some articles that say fungicide can't help, nothing can be done, but I just read taking out 6" of soil and covering with a tarp in hot weather can kill the leftover spores in the soil. I live in NJ, and we'll be having at least 1 last week of 80-90 degree weather, IF I can do that. I called the Rutgers Agriculture extension and they said the dead branches are due to the drought we've been having, but the splitting bark is more serious. I am not sure who to believe.
I would agree that the severe bark damage is likely a canker.
When the tree is stressed and is diseased it becomes susceptible to other infections and infestations, thus the ant issue. This could also be part of the reason for a difference in professional advice.
I would certainly treat the insects with Neem Oil. This works as both an insecticide and fungicide and works systemically.
Use it weekly on the tree. It is safe for people, pets and bees, so there is not harm in trying and using it.
Remove dead material and dispose of.
Time will tell if your tree continues to decline.
Best of luck.
Remember that a loss in the garden makes for new opportunities.
Though solarizing the soil around the tree can help the soil condition it would likely be to late for any effect on your tree.
I certainly understand your love and concern for this tree. These beautiful specimens are usually a focal point of a yard and when a tree has been nurtured for the amount of years that your tree has it's very hard to lose them.
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