This group consists of about 55 evergreen and deciduous creepers, shrubs and small trees that grow wild throughout the U.S., Canada, and Mexico south to Guatemala. Ceanothus are commonly known as California Lilacs, as many species are native of that state. Most Ceanothus are tender and need a mild climate in which to grow, though there are a few hardy varieties. These beautiful plants are mainly grown for their fluffy clusters of white, pink, or blue flowers. Ceanothus arboreus var. Trewithen Blue is a tender, vigorous-growing, large, spreading, evergreen shrub or small tree that is covered with large, ovate-shaped leaves. In the spring, large panicles of deep blue, lightly scented flowers are borne. It is better to grow this shrub against a wall, where it will have support if it becomes top-heavy. Ceanothus 'Concha' is a compact, medium-sized, evergreen shrub that has arching branches covered with narrow, glossy, dark green leaves. From late spring to early summer, a profusion of clusters of dark blue flowers open from red buds. Ceanothus 'Marie Simon' is a tender, medium-sized, deciduous shrub that produces panicles of pink flowers, in the summer. Ceanothus prostratus (Squaw Carpet) is a creeping evergreen that makes a thick mat up to 5 feet wide, with leathery, toothed, dark green leaves that grow opposite on the branches. In the spring, it is covered with bright blue flowers.

Most Ceanothus hybrids aren't hardy enough to survive too far North, but they also do not thrive in the summer heat and humidity of the East or Midwest. They should be planted in light, well-drained soil in a sunny site that is sheltered from cold, drying winds. Give carefully thought when choosing a site for your plants, as they resent being transplanted once they are established; this is especially true of the evergreen types. Most Ceanothus will not survive in hot, shallow alkaline soil, though some lime is tolerable. Most can be grown in coastal regions. It is better not to prune the evergreen types at all, except for removing dead branches in the spring. Deciduous types should have their lateral branches cut back to within 3 or 4 inches of the previous year's growth, in early spring.

Cuttings may be made from semi-hardwood shoots, in the summer. They are inserted in a frame that is kept closed until the cuttings form roots, which should be after five or six weeks. Seeds can be sown in the spring, but named varieties will not come true this way.

Ceanothus arboreus & var. Trewithen Blue;
Ceanothus 'A.T. Johnson';
Ceanothus 'Autumnal Blue';
Ceanothus 'Blue Jeans';
Ceanothus 'Blue Mound';
Ceanothus 'Burkwoodii';
Ceanothus 'Caskade';
Ceanothus 'Concha';
Ceanothus 'Dark Star';
Ceanothus 'Delight';
Ceanothus 'Edinburgh';
Ceanothus 'Gloire de Versailles';
Ceanothus gloriosus & var. Emily Brown;
Ceanothus griseus & var. Yankee Point;
Ceanothus impressus;
Ceanothus 'Italian Skies';
Ceanothus 'Marie Simon';
Ceanothus papillosus subsp. roweanus;
Ceanothus 'Perle Rose';
Ceanothus prostratus (Squaw Carpet);
Ceanothus 'Puget Blue';
Ceanothus 'Southmead';
Ceanothus thyrsiflorus (Blueblossom) & var. Millerton Point, repens (Creeping Blueblossom), Skylark;
Ceanothus 'Topaz';
Ceanothus veitchianus.