I recently had a patio installed. The contractor did an excellent job. However there is one problem. The contractor used a concrete bed and there is a 3 inch concrete border around my patio. I had planned on decorating around the patio with plantings and mulch. However, the concrete border is a problem. My husband wants to surround the patio with river rock and I think that is just too much rock and would make the patio look cold and hard. Any suggestions on how we could landscape this area?