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.
All of these South African natives form fountainlike clumps of strap-shaped leaves that are evergreen ...
Short-lived perennials in Zones 8–24, H1, H2; often treated as an annual in all zones. Many-bran...
Grows at a moderate to fast rate, eventually reaching 40–80 ft. tall, with a heavy-limbed crown ...