I have done a little research into this myself. I have come up with a few that I am trying out. So I am not sure what the end result maybe. Here are the few plants I am trying on the steep banks.Crown vtch, ice plants, and snow in summer. I have already had some trouble with snow in summer as it is too hot were I live for them to do good. So if you google search those plants you can decide if they may work for you.