Answer: Excessive sunshine will cause the leaves to lose their red color. This happens more with young maples than with older, more established ones so if your tree is young, it may adapt. If your maple has been established for several years and is exhibiting this behavior, it may never adapt and you might consider moving it. If you cannot transplant your maple to a shadier garden site, you may want to plant a tree or larger shrub to provide some protection from direct sunshine.
Best wishes with your garden!
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