Hi Peggy, A sandy hillside is tough for even tough plants to contain. Ornamental grasses, ivy, cotoneaster and hypericum are a few plants that could help but all can be invasive especially in a small area. A better choice might be to terrace the hillside using large boulders or timbers so that you create some level areas for plants. This could require heavy equipment and engineering advice if the area is large and the hillside is supporting soil that is near any building structures. A professional landscape designer with a background in soils would be the best person to give you advice on a situation like this. Keep growing, Marianne Binetti