Viscaria alpina (Lychnis alpina) (0.8lt)

Arctic Campion. Suited to a rock or gravel garden in full sun to light shade. Forms tufted mounds of grey green grass like leaves and has clusters of small bright pink flowers on short stems in late spring. Height and spread to around 20cm. Seeds freely if site is well drained enough. Good for cracks and crevices in walls, paving etc.