Guerilla Garden Ground Cover
 

I've done a bit of guerilla gardening this year but now need some suggestions for ground cover as the "soil" (and I use that term loosely) is quickly eroding. The garden is on an embankment between two roads and inclines at 30% at it's lowest point to 60 % at it;'s highest point. The "soil" is mostly clay and the garden is in direct sunlight all day and for most of the evening. As this is guerilla gardening all the flowers and herbs have been donations so if I'm going to spend $$$$ it has to be a "cheap and cheerful" purchase. We have alot of scilla in the neighbourhood so I would prefer to plant something else. I have planted some vinca but it's not taking off fast enough - any thoughts from the master gardeners (which I DEFINITELY am not!) ? Oh yes - must be able to tolerate some dog whiz and road salt given it's location.

I'm afraid I'd be out of my element to know what plants can withstand your cold winters. Avoid ivy as it attracts rats and snails. Guerilla?

Google 'ground cover slope' and you'll get plenty of information and tips, such as stabilizing the slope with sacking or mulch, then making holes for the plants, etc.
If you take a walk in your area and see what grows in similar conditions, you'll probably be able to dig up your starter plants from the wild. And since they are already highly adapted, you'll have a better chance of success.
My mother has an eroding bank leading down to her beach. Several years ago, she planted out a beautiful ivy my sister had given her in a pot. It spread beautifully. Remember even if you choose a species that dies back a bit in the winter, the root system will still be in place, although I would be inclined to plant something more hardy that provides at least some visual pleasure in winter.

Thanks for the advice!
A guerilla garden is a green-thumb-friendly-takeover (assumption without permission or authority to do so if you want the legalese) of either public space which is not parkland or abandoned private space. I'll post some before and after pictures when the garden comes into it's own. Mind you, with all the rain we've been having it may come into it's own a few feet down the street on a mud slide!

I planted some Periwinkle(Sp?)in an ugly empty spot and if you want a spreading,nonkillable,groundcover that's it...pretty bluish flowers in the spring and some through the summer.Grows in any soil!!