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. deep magenta-purple daisy-like flowers from mid-summer until the first frosts, 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 , Tresco Purple can grow up to about 50cm tall. Give it a sheltered, well drained site on any reasonable soil, and it'll put on a show for you.