Japanese Maple Dieback Cause??

[St. John]

Hey guys. A friend of mine has a Japanese Maple in the front yard. Approximately a 12 footer. It lost an entire trunk last year and now there is another branch that has died. It is specific to a single side. There is no evidence of pests. The tree was installed at the same time as the landscaping so root trauma is not likely.

There was an odd looking wound at the base. Wondering if anyone has thoughts.
The trunk pictures show the very base and the trunk to the picture left was the one that died. The other photos show just a dead branch (something else in the foreground).
Thanks everyone!
Location = Northwest Washington State.
View attachment 297693View attachment 297694View attachment 297695View attachment 297696View attachment 297697

 

[Raintree]

I don't see any insects or pathogens from your pics. Just a poor specimen of a Jap Maple, double stem w/ weak crotch & wounded stump, possible old nursery bruise. Tip die back most likely from winter injury.

 

[St. John]

I don't see any insects or pathogens from your pics. Just a poor specimen of a Jap Maple, double stem w/ weak crotch & wounded stump, possible old nursery bruise. Tip die back most likely from winter injury.

Thanks for the assessment. I tend to agree that it is potentially a nursery defect. The open healed wound also looked to me like a sun scald or like you said, a nursery bruise.

The only thing I am not sure about is the damage from a winter injury. We had a super mild winter here. only one or 2 days where it dipped below 32 (hence the tent caterpillar onslaught currently going on).

They like the tree but I don't know what to do to prevent more dieback.
I was considering some rootzone aeration on the side having problems, combined with addition of mychorrizae, maybe sealing the wounds after bark tracing them.

 

[Raintree]

I would leave the wounds alone, get a soil test done & keep the tree well mulched.