Get rid of the lawn if that is what that is. You may have to go in stages so the soil doesn't just slump out onto (the road? the sidewalk?) Plant long rooted and mat root/spreading root plants to hold the soil in, like ornamental grasses, daylillies, iris, rudbeckia whatever is appropriate for your growing situation. If money allows terracing would make sense, then you could put the space to use as for edibles, seating etc. If not, low maintenance carefree spreading plants, no invasives though that's what the previous homeowner did here where I live (English ivy, goutweed, vinca) and it was a nightmare to get back under control.

Terracing is another thought.....

This could be done in stages?

Best advice is hire a landscape designer who can specify what when and where and then do the yard in stages.....

This is another pretty idea for a sloped yarr......remove all plantings and regrade your slope. Resod half of it and install some sort of entry path that works with your house architecture. Do slope loving planting on the other side....you could do sod, walkway, plantings in stages over the seasons possibly....it is a very pretty and simple design.

No, is not "Hillside terrace gardens are a great way to grow an array of plants and vegetables without the worry of having all your hard work simply wash away. On steep slopes, terracing can make planting a gardenpossible. Terraces prevent erosion by shortening the long slope into a series of shorter, more level steps."

if you think that terraced gardens are another thing this is your problem

Huh?

http://www.finegardening.com/shrubs-slopes

http://www.bylands.com/blog-entry/plants-steep-hills

http://www.telegraph.co.uk/gardening/how-to-grow/how-to-plant-a-steep-sunny-bank/

http://guelph.ca/living/house-and-home/healthy-landscapes/landscape-planning/sample-garden-designs/planting-slope/

J Williams: was a answer to Susan

The only real solution for this strong a slope is terracing. Check out photos, find a look you like, start on bottom layer and work you way up. Probably need 3-4 steps. Start gathering broken concrete. You can use that with aggregate sides exposed as walling material. Once you start looking for it you will be surprised how much is laying around. Almost no cost aside from sweat equity. Read up on how to terrace properly. YouTube videos provide visual and technical help. Start in Spring.

Vatrice, Houzz has a Landscape Design forum. Click here.

You will be asked to provide more photographs. I don't see a need to terrace. There are ground cover plants for erosion control. It could be made more attractive.

Use the forum but know your zone, how much sun you get, and lots of pictures. They do not generalize, they will give advice down to the type of worm you need in your soil.

Terracing isn't always the biggest bang for your buck. Do you have a budget you're trying to stay within for this project? I know you have the backyard thread too, and what looks like a new deck. Is this a new (or new to you) home?