Campanula poscharskyana 'Blue Waterfall' (Serbian Bellflower)
Cascading star shaped blooms in a lavender blue shade bring cool color to the garden for a long period from late spring to early fall..  The tight bell-like buds open to full blue stars with a white eye that cover the dark green, heart shaped foliage.  It grows 8-10" tall and spreads to 2' wide by underground stems.  It prefers partial sun with regular water to start but will tolerate some dryness once established.  This plant's low spreading habit is ideal for tumbling over a wall, planting in a rock garden or along a path, or trailing over the sides of a container or window box.   Shear the plant occasionally to keep it looking neat and tidy.