i use a lot of crown vetch and am very happy with that on the yards edges. looks good, covers good and the weeds and grass dont stand a chance. anything else i can use? im in north western ne. at 4000 ft. what can grow here and be as good as crown vetch? i like different things and im sure i am missing out on a couple of good ground covers. i want them to come back each year with out replanting.