Ceratostigma plumbaginoides
Common Name: plumbago 
Type: Herbaceous perennial
Family: Plumbaginaceae
Native Range: Western China
Zone: 5 to 9
Height: 0.75 to 1.00 feet
Spread: 1.00 to 1.50 feet
Bloom Time: July to September
Bloom Description: Deep blue
Sun: Full sun to part shade
Water: Medium
Maintenance: Low
Suggested Use: Ground Cover
Flower: Showy
Leaf: Good Fall
Tolerate: Erosion, Clay Soil

Culture

Easily grown in average, medium, well-drained soils in full sun to part shade. Somewhat wide range of soil tolerance except for wet, poorly-drained ones. Appreciates some afternoon shade in hot summer climates such as St. Louis. May not be reliably winter hardy throughout USDA Zone 5 where it will benefit from a light winter mulch. Spreads by rhizomes and can be somewhat aggressive in optimum growing conditions.

Noteworthy Characteristics

Ceratostigma plumbaginoides, commonly called plumbago or leadwort, is a wiry, mat-forming perennial which spreads by rhizomes to form an attractive ground cover. Typically grows 6-10" tall on generally erect stems rising from the rhizomes. Oval to obovate, shiny, medium green leaves (to 2" long) turn bronze-red in autumn. Terminal clusters of 5-petaled, gentian blue flowers (1/2 to 3/4" diameter) appear above the foliage over a long summer to frost bloom period. Flowers resemble those of woodland phlox.

Genus name comes from the Greek words keras meaning a horn and stigma from the hornlike projection on the stigma of the flower.

Specific epithet means resembling the genus Plumbago.

Problems

No serious insect or disease problems. Will spread.

Uses

Late, long-flowering plant serves as excellent ground cover for sunny to partly shaded areas in the landscape. A good plant for interplanting with spring bulbs because foliage emerges late as the bulb foliage is dying back. Underplanting for shrubs. Edger. May be used in rock gardens or border fronts with careful monitoring of spread. As a ground cover, plumbago would probably be as extensively planted as vinca, pachysandra or English ivy, except for the fact that it lacks their evergreen foliage.