Sounds like a tough site to fix. I am guessing this is not a place where you need to walk...useful space. You mentioned having a fence. I am guessing this will be up closer to the house...right?

One tough old plant that can take a lot of abuse is the perennial vine, Vinca Minor. You would have to water most anything to get it established. Might even need to make little pockets of decent soil to plant it in, but it will hold a bank in time. I have seen people do a whole hillside up here. It will mask over the places where rain has cut trenches in the hillside if they aren't too deep and wide. As it grows, you can toss some fine organic matter (ground leaves, compost, etc.) over it to help it take hold. Eventually it will trap leaves and sort of make it's own. I have seen it nearly covered with leaves, but in the spring it comes right up through them and they end up feeding the Vinca Minor. It will tolerate the full sun, or shade, but I would try to water it for a year or two...not a lot, but enough to keep it from wilting down too much. It pretty much grows in all directions, so you might need to plant in rows or staggered pattern over the hill side.

If you want to try this one, email me...I may be able to help with dormant plants this late fall. Best time to start them in your zone, I would think. Early spring works, but would take more water to get established.

Honeysuckle is used on roadside banks too steep to mow in Missouri, and it will cover. But, it does stand taller. Not sure about training, but don't see why not. Just place the runners where you want them and peg them down with a hair pin shaped piece of coat hanger, or lighter wire if you can find it. Up here, I would use rocks. LOL It might do the job faster. Or, you could put the Honeysuckle midway down the hillside and train both ways, then put the Vinca Minor up closer to where your fence will be. That way maybe your decorative fence will stay visible. ;O)

How much area does this space cover? I agree that vinca minor (periwinkle) and honeysuckle are good bank covers. You mention trees. What kind of trees, how much spread, and are there surface roots? We've had good luck on the bank outside of our fence with iris and day lilies. There is also the honeysuckle and periwinkle ground cover ( over a very rocky and dry area). Periodically it, gets cut with a weed eater. That's all. We also build up the areas under the trees with the fall leaves. We put them in piles and leave them. We usually keep them in place with welded wire cages. In spring we put on some top soil and plant in it. We have transferred day lilies , iris, and stoksia aster into a dry corner area under trees. Tiger lilies and tall phlox are also doing well there. The phlox was there when we came here 18 years ago. The only thing we have done to it has been to thin it out and cut it down when finished blooming. It is in full bloom now. I feel the most important thing is to build up the soil well enough to nurture the roots of the plants and to choose plants with shallow roots or rhizomes, such as the iris and day lilies. That also helps with the erosion. There is nothing blooming continually but the day lilies follow the iris and there has been color since spring. Many of the plants we have used have been divisions shared by neighbors. One of the prettiest gardens I have ever seen was a corner of a city block filled with zinnias entwined with blue morning glory. It might be a little hot and dry now for seed sowing but zinnias germinate and grow fast and come in many shapes, sizes, and colors. For a fast annual garden a variety of zinnias would be enough. Last fall when the zinnias had gone to seed I pulled them and piled them around a stump. There is now a patch of blooming zinnias there and I haven't done another thing to it. We also have a self sowing petunia that returns year after year and homestead purple verbena which has been very durable. Hope you will give us feed back. EP

Here is another plant that does very well as a bank and ground cover. Link below. EP

Here is a link that might be useful: showy pink primrose

being a flower lover myself, i sort of hate to mention these, but how about some grasses or wisteria, i have wisteria growing in dry sandy soil and it thrives, no rain and no water for over six weeks and it still thrives!!
how about salvias? there are several that like it dry and the western sun wouldn't bother them!!

All the above are good suggestions. I have seen the showey pink primrose growing in nothing but and inch or two of dirt that vehicles tracked onto a paved street in Berryville, AR. You know how it will end up along a curb...they have been blooming in that street for as long as I have lived here...hard to believe. Only problem is that they are kind of ugly when finished blooming, but if mixed with some other plants might work out well. They must throw their seed because they will spread all over the place.

The problem might be too much shade depending on how dense the trees are.

The homestead purple verbena blooms after the pink primrose and would be a nice combination with it. Ours are in full bloom now. They are native to Arkansas and very durable. The sunlight/shade factor is significant. The periwinkle will grow anywhere, in shade or full sun. Ours needs to be cut back with a weedeater periodically but once there it is there forever. The primrose and verbena also need periodic trimming.EP

Welcome Julie!
My yard is pretty flat so I can't give you any advice. It does seem like your landlord would be happy for you to make improvements. Maybe you can sneak in a little or show him some photos of what you'd like to do.
The book below has some great photos and ideas in it and is probably available at your library.
Best of luck - Christie

Here is a link that might be useful: Hillside Landscaping - Sunset Books

Thanks, everyone, for your input :)

Well - I tried two things: First, I bought some evululvous? (serious spelling check needed, but they're little blue flowers that "vine" a bit...) and I began digging...Years of being a dirt yard has ground the soil down to the stone - so I didn't get very deep. I ran out of energy and enthusiasm for it after digging two medium sized holes.

So, I decided to get a bunch of ivy and plant that all over the hill - easier to dig for, easier to care for and by the time it's grown completely up the hill, I won't live here :)

So - that's what I've done, quick and simple - I had all the plants planted in two days.

There is other work I want to do to the yard - around the trees, I think I'll make white-stone beds with potted flowers and a bench or two, perhaps....Up by the house, where there is nothing, I'll make a small bed with some elephant ears, or something of that sort.

I'll keep you posted, and I'll post pics when I can :)

Thanks for your input, much appreciated.

Hope it works. Good luck. EP

Here is a link that might be useful: link

Grow native.
There are a lot of native plants, wildflowers, grasses that will do well in poor soil and conditions that you describe.
Native plants evolved to flourish in this area, and once they get going, maintenance is minimal. They take a few years to establish from seed and so may not work in your situation, but long term, natives are the way to go.

May I ask why you are growing something UP a hill instead of DOWN it? It seems to me it would be easier to grow it down. There are quite a few sedums that are pretty rampant you could grow in full sun and also the orange daylily "fulva" which is called ditch lily. I have those growing on a bank and they spread very quickly and are pretty with Queen Anne's lace mixed in.

Nancy