We have this steep hill in our backyard that is about 12-15 ft. It's so steep, that you can't mow the hill, even w/ a self propelled mower. This hill is also runs in our ajoining neighbors, which is higher in their yard. We really need some serious landscaping advice as to how we can maintain this hill properly. We've thought about putting up a retaining wall & creat a flower bed at the top, but we figured that would cost us an arm & a leg. We could put schrubs thru out the hill, but we just can't get seem to agree on anything.