Laying a blue blanket across California hillsides each spring, Ceanothus (California lilac) is a large genus of North American native shrubs in the buckthorn family Rhamnaceae. The genus includes more than 60 species of highly fragrant plants, ranging from low-growing shrubs to small trees. Many varieties are endemic to California.
Keanothos is Greek for ‘spiny plant’, a fitting description for this evergreen family. Many species feature sawtooth-spined leaves, similar to holly with their sharpness and glossy green surface.Often marked by three strongly delineated parallel veins from the base, the leaves range in color from dark green to gray green or variegated, and are quite pretty.
While flower colors may be occasionally be white or pink, Ceanothus has achieved its place as a gardener’s prize due to the ‘true blue’ color of its masses of showy blossoms.
From frosty light blue to breathtaking cobalt and indigo, the flowers are stunning against the backdrop of glossy green leaves and plum-toned buds as they bloom out each spring (March – May or longer, depending on cultivar.)
Soil and Water Requirements
As a true California native, ceanothus grows best in conditions that mimic wild habitat: dry, well-drained soil, particularly slopes or banked areas. While new plants should be lightly irrigated with spray heads, once established, plants will thrive on natural rainfall and morning dew alone, making them a valuable addition to a water-conscious, low-maintenance garden. With appropriate care (or neglect?) many species have life cycles of 15+ years.
For best practice in pruning ceanothus, think “light nibbling”, like a deer. They don’t get very far into these spiny-leaved shrubs, and neither should you! New growth can be cut back to healthy leaf sets through mid-season to keep size in check.
Deep cuts (branches more than 1 inch in diameter) will cause damage. It is important to avoid pruning late in the season; it can trigger new growth, vulnerable to die-back, if cold autumn weather moves in earlier than expected.
Ceanothus Features and Uses
Ceanothus earns its spotlight status for a long list of highly-desirable traits:
- Attracts birds, bees, butterflies, and other beneficial insects
- Grows quickly and can fill in large spaces in a short period of time
- Variety of garden use: works well as screens, hedges, groundcovers, specimens, wall plantings, shrub borders, and as container plantings
- Thrives despite near-neglect level of care (low/no watering is a must)
- Deer resistance: the less water and fertilization in the soil, the more deer resistant the plants become
- Medicinal: according to the UC Sonoma County Master Gardeners, a historic use for fresh or dried flowers of some varieties was lathering into soap, providing relief from poison oak, eczema and rash.
We carry dozens of Ceanothus varieties and would love to assist you in choosing the plants that are right for your garden. Visit the nursery for personal guidance, or use the Plant Finder to browse our selection before you arrive.