dying japanese willow tree

Question

My Japanese willow trees have been thriving in my garden beds for 6 years. Two summers ago, the trunk bark started splitting. I called the nursery where I purchased them and he said they did that sometimes and not to worry. Well, then this past summer, 3 of them came out on one side and the other side was dead. I had to cut them down. Now it appears that another one is doing the same thing. We live in the mountains of North Carolina. I cut the tree branches back each spring and clip during the summer months as needed to keep them off the ground. Deer have damaged one, but I have the others protected. I see no pests on them. My only thought is that they may be a short lived tree?? We have had plenty of rain this summer and fall. Thoughts? Thanks a bunch!

Answer 1

Japanese Willow are susceptible to a few diseases and insect issues.
Blight, Crown Gall, fungus, root rot, cankers, rust, Willow Scab,
leaf spot and powdery mildew are all issues associated with Willow Trees.
Pruning out any diseased material and disposing of it the right thing to do.
You can severely prune out the the plant and leave little healthy growth and still likely have a viable tree.
The problem may be able to be overcome by removing all the diseased branches.
Thinning out 1/3 of the old branches every year or two will help.
Older wood is susceptible disease.
In general bark splitting is generally not an issue.
It could be a result of environmental issues; winter frost, sun and sun scald can cause splitting.
A healthy tree can generally heal itself.

https://www.gardeningknowhow.com/ornamental/trees/willow/dappled-japanese-willow.htm