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 2 1/2 to 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.
Many-branched plant 6–12 in. high, 1/2 –3 ft. wide. Oblong, 2– 4-in., bright green o...
Grows at a moderate to fast rate, eventually reaching 40–80 ft. tall, with a heavy-limbed crown ...
From Japan. Possibly the hardiest of the banana clan. To 15 ft. tall, with narrow green leaves about 8...