Soil: fertile, well-drained, neutral to alkaline soil
Rate of growth: vigorous
Flowering period: April to June
Hardiness: frost hardy (needs winter protection in cold areas)
In mid-spring, this spreading, evergreen shrub is an arresting sight, smothered in dense clusters of dark blue flowers. It makes a superb specimen plant for a south or west-facing border among spring-flowering bulbs, and when has finished flowering, provides an excellent foil for later-flowering deciduous shrubs and perennials. It needs a protected site, as the deeply veined, dark green leaves are easily scorched by cold, drying winds.
Garden care: Each year after the plant has flowered reduce the shoots by one third and apply a 5-7cm (2-3in) mulch of well-rotted organic matter around the base of the plant.