We have a relatively newly planted maple tree(maybe 2 years) and this year we have noticed it is full of tiny red dots all over the leaves. What needs to be done, if anything? We live in Germantown, WI, zone 5.
This sounds like galls. They are caused by tiny insects or mites and although they can disfigure the leaves somewhat, they're generally harmless. And there's not a lot you can do about them in any case.