RHS 
Herbaceous Perennial
A low-growing perennial to around 45cm tall with oval to oblong, toothed leaves forming a basal rosette. In late spring and summer, erect, hairy and leafy stems bear dense, terminal clusters of pale lilac, blue and white bell-shaped flowers
Position
Full sun, Partial shade
Soil Types
Chalk, Loam, Sand
Max Height
0.1-0.5 metres
Max Spread
0.1-0.5 metres