This is the back of my new construction... It's pretty long, about 100 feet wide, 10 feet tall, and 20 feet deep, so it's quite steep as well. The builder wants to put grass there but I think it will be too dangerous to mow. I'm thinking about planting groundcover like vinca (the slope gets full sun in Summer). I know it takes a long time for groundcover to get established, so shall I mulch the whole area for now? Is weed barrier fabric needed? I heard mulch will be washed away by rain... If I let the builder install sod there and plant vinca later, would it be difficult? Any ideas highly appreciated!