Experts and BHG readers answer.
maple tree with raised roots
Sadly, there's not much you can do. Maple trees are notoriously shallow rooted and compete heavily with anything planted near them. You also can't put soil on the exposed roots without possibly damaging the tree. I would recommend you use a loose mulch such as shredded bark which won't suffocate the roots and then set pots of colorful shade-loving annuals underneath."