Great idea but I would need to know about the sun exposure, climate and type of soil to make the best suggestion. If you have sun and soil that is acidic than some low growing heather would be good, or in poor, dry soil sedums and succulents but for pollinators the magic carpet spiraea shrubs and if you live in deer country then some ornamental grasses such as blue fescue. Sometimes the best answer is to see what is growing well in your neighbor\'s yard or in the parking strips of commercial buildings in your town. Ivy as a groundcover is not recommended as it grows too invasive but kinninnick or bearberry is a native evergreen for the Pacific Northwest that is being used for sloping ground in my climate. You can add boulders or large stones to help create planting shelves so the new plants will not be planting on a such a steep slope.Keep growing, Marianne Binetti