I have an oval cemetery with 9 stones in it in the entryway of my ranch. My husband and I cleaned it out when we purchased the property; it was all weeds, tall dead trees, sticker vines, poison ivy et. I have killed everything in it 3 times, and then tried to plant groundcover (waiting the appropriate time), but the weeds and crabgrass always win. Watering is a problem. Any ideas what I could plant in there that would take hold before the weeds converged? I tried 100 red sedum, but no luck. It is about 40 ft x 80 ft. Thanks! Also, don't want to obscure the tombstones like they were when we purchased.