What kind of plants/shrubs have shallow roots that will grow over concrete that's 8 inches deep?

We just bought a house, and to my horror, when I went to plant the azelea's I just purchased, I discovered a concrete slab about 8-10 inches under the dirt. It is the "brace" for the fireplace so I can't have it removed. I want to landscape the entire front of the house and the spot where the concrete is will be bare and ugly unless I can find something that will actually grow there without harm.