These durable plants are valued for their clusters of intense blue, phloxlike flowers that bloom in summer to late fall, when cool hues in the garden are most welcome. (For pale blue flowered Cape plumbago, see Plumbago auriculata.) Tolerate inconsistent watering. Not browsed by deer. Shrubby species are usually treated like perennials in colder zones; cut them back after bloom, and mulch heavily.
C. griffithii. BURMESE PLUMBAGO. Evergreen shrub. Zones MS, LS, CS, TS; USDA 7-11. Himalayan native. Resembles C. willmottianum but has rounder leaves and more compact, somewhat lower growth (to 2123 ft. high and wide). Also blooms somewhat later. Growth often nipped back by frost. White-blooming selections are available.
C. plumbaginoides. DWARF PLUMBAGO. Perennial. Zones US, MS, LS, CS; USDA 6-9. Native to China. Wiry-stemmed ground cover 612 in. high. Bronzy green to dark green, 3-in.-long leaves turn reddish brown with frosts. Most effective in early or midautumn, when blue flowers contrast with red fall foliage. In loose soil and where growing season is long, spreads rapidly by underground stems, eventually covering large areas; plant 1112 ft. apart for quick cover.
Dwarf plumbago is semievergreen only in the mildest-winter areas; best to cut back after bloom. Dies back elsewhere; leafs out late in spring. When plants show signs of aging, remove old crowns and replace with rooted stems.
C. willmottianum. CHINESE PLUMBAGO. Deciduous shrub. Zones US, MS, LS, CS; USDA 6-9. Grows as airy mass of wiry stems 24 ft. high and wide. Deep green, 2-in.-long leaves are somewhat diamond shaped, with tapering tips; turn yellow or red and drop quickly after frost. 'Palmgold' ('Desert Skies') has golden leaves.