Family: Rhamnaceae
Common Name: Californian Lilac

These pretty, decorative, evergreen shrubs originate mostly from California and other parts of western North America where they are much grown. They grow quickly, but may he short lived in some climates. A few species are deciduous and many flower both in spring and autumn. Many hybrids and cultivars have also been developed, particularly in France and England.

Species

C. cyaneus grows 2 m (6 ft) tall and produces cornflower blue flowers.

C. dentatus, with deep blue flowers, is one of the hardiest, most frost-resistant species. It grows to 3 m (10 ft).

C. impressus, zone 7, is a low-growing or prostrate plant, with a dense, spreading habit. Clusters of pretty, deep blue flowers bloom profusely during the spring.

C. thyrsiflorus is a very hardy species, with bright blue early flowers, which grows to 4 m (13 ft). The cultivars and hybrids include 'A. T. Johnson', to 4 m (13 ft), with rich blue flowers in spring and autumn; 'Burkwoodii' with bright blue flowers; 'Marie Simon', to 2 m (6 ft), with large clusters of pink flowers; C. x veitchianus, a very hardy hybrid, to 4 m (13 ft), with deep, bright blue flowers. New low-growing cultivars have been developed in California, including 'Emily Brown', with violet flowers; 'Joyce Coulter', with dark blue flowers; 'Julia Phelps', with cobalt blue flowers; and 'Yankee Point', a very hardy, wide-spreading plant, with bright blue flowers. All are suitable for growing on banks.

Cultivation

Ceanothus need a well-drained soil and full sun, generally doing best in an open situation, though they may require staking. They can be trained against a sunny wall in cool regions. Prune after flowering to retain shape and stability. Propagate from cuttings of firm, heeled sideshoots, taken in autumn. Strike in a light sandy loam, without heat, and pot as soon as they strike. Ceanothus dislike root disturbance, and transplanting of advanced plants is not advisable.

Climate

Prefers a cool climate or areas with hot, dry summers and cold, wet winters.