Osteospermum 'Snow Pixie'

The African Daisy is a very popular low growing ground cover perennial for the front of a sunny border, although it looks equally good in pots and planters.  The large white single daisy like flowers with a central yellow disc can ofetn last for months in summer, and it will carpet an area almost a metre across when mature.  Said to be half hardy and requiring protection from frosts, but I know a wind blasted hillside in North Yorkshire where on the southern facing slope it's lived quite happily for years.  Evergreen, though it may lose some leaves in a cold winter , Snow Pixie can grow up to about 40cm tall.  Give it a sheltered, well drained site on any reasonable soil, and it'll put on a show for you.