San Diego ceanothus is a large woody evergreen shrub or small tree native to southern California. It has gray-green bark and long wand-like branches bearing darker green leaves. Its most notable feature is the very showy medium blue flowers that appear in bunches from March to November. As one of the prettier ceanothus species, it is well-suited for coastal gardens where its long blooming season and habitat value for pollinators are appreciated. It requires full sun, tolerates various soil types and little summer water once established.

1. * San Diego Ceanothus – Ceanothus cyaneus
( see-an-OH-thus sy-AN-ee-us)
Family: Rhamnaceae (Buckthorn Family)
Native to: S. Peninsular Ranges, San Diego Co. ; rare on dry shrubby slopes to 1200'. Often in
dense chaparral with Chamise. Manzanita other shrubs.
large woody shrub/tree
mature height: 8-15 ft. mature width: 6-8 ft.
Tall, erect evergreen shrub/small tree.
Bark gray-green. Branches long, open-branched, almost
wand-like. Leaves toothed or smooth, darker green above and lighter beneath. Fast growth.
Growth characteristics:
Blooms primarily in spring (Mar-June) but may bloom off and on to Nov. in
gardens. Flowers in bunches on 6-8 inch stems above the foliage; shape typical for Ceanothus.
Flowers begin as dark blue buds becoming medium blue in full-flower. Very showy.
Blooms/fruits:
Uses in the garden: One of the prettier Ceanothus for garden use, with long bloom season and very
showy blooms. Good as a large evergreen shrub in bigger gardens, particularly in coastal areas.
Great on slopes.
Open growth habit makes it a good choice for training as a narrow screen or
espalier - looks great with Fremontias. Train also as small tree. Cultivar ‘Sierra Blue’ is a hybrid –
does well in heavy soils. Cultivar ‘Cal Poly’, also a hybrid, is good for well-drained soils along coast.
Sensible substitute for: Non-native evergreen shrubs; other Ceanothus.
Excellent bird habitat: provides cover and seeds for food.
insects, particularly bees.
Attracts:
Flowers attract pollinator
Requirements:
Element
Sun
Soil
Water
Fertilizer
Other
Requirement
Full sun (best) to part shade.
Most soils including clays.
Little needed after establishment (Zone 1-2 best)
Likes an organic mulch; leaf mulch is great.
Management:
Prune to shape after blooming in summer. Can tip/heading prune for denser shape.
Propagation: from seed: needs heat/smoke treatment
by cuttings: softwood in summer
Plant/seed sources (see list for source numbers): 1, 3, 8, 13, 20, 24
11/29/10
* Native to CA but not to Western L.A. Co.
© Project SOUND