Beautiful sky-blue flowers.  This shade of blue is rare among all the various perennials.  Blooms begin in early June for us, bloom for quite a long time (several weeks).

Dainty foliage, height to 20 cm. Needs to be grown in shade, we've found the plants wilt in intense sunlight.  Is not happy if it dries out.  Likes soil which is rich in organic matter. The foliage dies down a fair bit once the plant is done flowering and hot weather begins.

Hardy to zone 5.

Glen's score:  8.