light brown spots on Japanese maple

[Ted Shoemaker]

Hello,

We planted a young (2-ft tall) Japanese maple "Red Select" about two weeks ago. Now it is showing some small, light brown, dry-looking spots on otherwise healthy-looking leaves. Is this a matter of concern?

Thank you.

Ted Shoemaker

[David E. Ross]

Japanese maples require a light, slightly acidic soil. They also prefer a climate where the air is humid during the growing season.

Where I live, I have seen Japanese maples in heavy clay soil. The soils and water both tend to be alkaline. Last week, we had several days when the relative humidity generally stayed below 30% after reaching 8% on 30 April. The maples here show severe stress by July and start to lose their leaves in September while other trees are still growing vigorously.