Hi, Well the choice of plants is really up to you. You certainly don't want to plant too close to the tree because maples have shallow root systems, but any low growing perennial might work great. Catmint for example, blooms almost all summer and has great blue color that would contrast nicely. Walker's Low is a great variety. I'd go to our Plant Encyclopedia on this website and do an Advanced Search and I'm sure you'll find exactly what you need.