[Help] Possible Fungal Issue with Japanese Maples

[ajm55555]

I've seen similar small stripes on my maple and it seems to me they tend to be more visible on young branches, as Sergio said, when the tree is in the growing season. I think it's the effect of the trunk getting bigger. They tend to disappear/heal away in the fall and winter.

 

[Eric Group]

The neem oils may take care of both the scale and the tree. Japanese maples are sensitive to petroleum based horticultural oils, but I'm not sure about Neem.

No sir- I use Neem oil in JM every year without issue. Used it this Spring as a matter of fact and it cleared up a little bug infestation I was getting. I think Neem is one of the most mild options for horticultural oils... But is still pretty effective for a wide range of issues!

 

[papymandarin]

i agree with mach5, that's perfectly normal, it's "growth cracks", just a sign that the places where they appear are enlarging, they are also the starting points of the barking, that give the strypy look of mature bark, next year wehn you wi look the places where you have white lines, it will have become bark