A group of semi-tender and half-hardy shrubs and herbaceous perennials with bright blue flowers.
Botanical Name: Ceratostigma (ke-ra-to-stig-ma)
Common Names: Shrubby plumbago, leadwort
Foliage: Evergreen or deciduous, simple dark green leaves. Good autumn colour.
Flowers: Short spikes of saucer-shaped, attractive, bright blue flowers.
Flowering Period: Late summer into autumn.
Soil: Moist but well-drained or well-drained soil (chalk, clay, sand or loam). Acid, alkaline or neutral pH.
Conditions: Full sun. Plant in an east or south facing aspect, in a sheltered position.
Habit: Bushy, clump forming.
Type: Shrubs or herbaceous perennials.
Origin: Asia and tropical Africa.
Hardiness: Reasonably hardy through much of the UK. Although the woody stems often die back to the base in winter, they will regrow in spring.
Plant in the spring. Suitable for a wide variety of soils, including chalk.
Best grow in moderately fertile, free-draining loam, in full sun. Ideally sited in a sheltered position at the base of a south or west facing wall.
Retain stems over winter to provide some protection and cut back the old growth hard in the spring.
Can be affected by powdery mildews.
Take softwood cuttings of young basal shoots in spring or take semi-hardwood cuttings in summer.
Increase perennials by division in the spring, just as the young shoots are emerging.
Ceratostigma plumbaginoides (Plumbago) is a bushy perennial with reddish stems and hairy green leaves. Purple-blue flowers in August-October. Can become invasive. Height 12 to 18in (30-45cm), spread 3ft (90cm).
Ceratostigma willmottianum (Miss Willmott's Plumbago), is a deciduous shrub with bristly, purplish stems with small, coarse green leaves. Dense clusters of brilliant blue blossoms in July-October. Height up to 4ft (1.2m).