I have two pots of Lesser Periwinkle (Vinca minor). The blue flowered form is sometimes referred to as 'Bowles Variety' (after EA Bowles) and the white flowered variation as 'Gertrude Jeckyll'. Those renowned gardeners both had a special place in their hearts for the humble Periwinkle. It probably came to us from the continent in centuries past but I see it in woods from time to time among other flowers of the forest. Perhaps it's always been here?
 It should be ideal for the semi-shady environs of my back garden and I've planted it in a number of spots. It's noted as a tough groundcovering plant but in my case refuses to cover any ground at all! A few sprigs hang on with the odd flower from time to time but that's about it.
 Anyway, the trailing habit of V. minor makes it very attractive spilling out of pots and both the blue and the white are flowering merrily.