Serbian bellflowers have an easy, undemanding habit. Creating a stream of lavender blue, the 1-inch-diameter star-shaped blossoms bloom reliably from late spring to early fall. The foliage remains evergreen in mild winters and needs to be sheared only once in a while to keep its appearance tidy. ‘Blue Waterfall’ flows beautifully along bed edges and through rock gardens in full sun to partial shade. Long bloom period. Low maintenance. Good ground cover.