Our recommendations will depend to some extent on whether your bank faces north or south, and what type of soil you have. But Humulus (golden Hop) is a quick growing climber which dies back in the winter and seems to grow anywhere. Evergreen spreader is Vinca (periwinkle; dark blue or light blue); perennial Geraniums for colour: spread from year to year once established.

Obviously you have space for several different plants.

You might consider Crown Vetch. It is a EXTREMELY fast and aggressive ground cover which is very successful without any attention. It is used often in hard to reach areas to prevent soil erosion.