Vigorous and long flowering with large (up to 5cm across), saucer-shaped, violet-blue flowers with white centres. Forms mounds of slightly-marbled, deep green foliage. Perfect for underplanting roses, or filling a few gaps in the front of a border. 

Winner of the RHS Plant of the Centenary at Chelsea Flower Show 2013

Flowers in summer
Ideal for full sun or partial shade
Well drained fertile soil
Height 60cm
Spread 80cm