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 Taiwan. Forms a compact clump to 2 1/2–3 1/2 ft. high and 3–4 ft. wide, with nar...
From China. Grows to 15–20 ft. tall, but can be held to 4–8 ft. New culms emerge green, bu...
Native to China and Japan. Erect growth to 2 ft. tall and 1 1/2 ft. wide. One of the few ferns with se...