Valued for clusters of intense blue, phloxlike flowers that bloom in summer to late fall, when cool hues are often especially welcome in the garden. (For pale blue-flowered Cape plumbago, see Plumbago auriculata.) Tolerates inconsistent watering. Shrubby species are usually treated like perennials in colder zones; cut them back after bloom and apply a thick mulch.Ceratostigma griffithii
Himalayan native that grows to 2 1/2–3 ft. high and wide, with roundish, deep green leaves. Even light frost will nip back the growth on this plant. Blue, phlox-like flowers appear in fall.
Native to Asia Minor. Tuberous-rooted plant 1 1/2 to 2 ft. tall and wide, with fresh green, almost fer...
From Korea and Japan. This is a tropical-looking shrub with long-stalked, big, glossy dark green, deep...
Native to South Africa. Performs best in areas with warm, dry summers. Bold, straplike leaves form clu...