We have just completed a pool project in South Jersey. The pool has a raised wall and a signicant slope behind the wall that is approximately 40 feet wide X 20 feet deep X 6 feet high. Rather than bringing in 20 ton of 3-5 inch river rock to cover the area, I'd like to consider some natural non-invasive ground covers to be part of the landscape. The area gets shade in the early morning and full sun from about 10-11am on. I'm looking for something (or variety of things) that is low maintenance, attractive, and is good at keeping weeds and crabgrass in check.