Planting sloped area outside house which had grass

Unusually for housing estate have small triangle of grass between footpath and garden wall. Not sure of ownership but trying to check with council. With advancing years have removed grass from front and back garden, leaving this as only tiny patch requiring mowing and ownership of law mower. Thinking Mypex, and trailing plants, biggest problem is slope making mulch or chippings difficult to keep in place. Suggestions of plants etc.