Data provided by the participants of the Consortium of California Herbaria

View additional distribution information on the Jepson eflora

Ceanothus oliganthus is a species of shrub in the buckthorn family Rhamnaceae known by the common name hairy ceanothus. It is endemic to California, where it can be found in most of the coastal mountain ranges in dry habitat such as chaparral. This is a large, erect shrub approaching 3 meters in maximum height. The evergreen leaves are alternately arranged and may be up to 4 centimeters long. They are dark green on top, paler and hairy on the underside, and are edged with hairy teeth. The flower cluster is a cluster or series of clusters of blue or purple flowers. The fruit is a capsule which may be hairy or not, depending on variety. There are three recognized varieties with overlapping ranges. The variety of this species known as jimbrush (var. sorediatus) is sometimes treated as a separate species.

Plant Ceanothus oliganthus on rocky slopes, particular north facing ones in the southern, drier parts of its range. This plant is fairly sensitive to summer water. Best to avoid all direct summer water after it's first year, though it will be happiest if it can stretch its roots out to a damper or irrigated area 10 feet away or so. This plant likes full sun but tolerates part shade.

Plant type

Shrub

Size

10 ft Tall
12 ft Wide

Form

Mounding

Growth rate

Moderate

Dormancy

Evergreen

Fragrance

Pleasant

Calscape icon
Color

Blue, Purple

Flowering season

Winter, Spring

Special uses

Bank stabilization, Hedge

Sun

Full Sun

Water

Very Low

Summer irrigation

Max 1x / month once established

Ease of care

Moderate

Cold tolerance

Tolerates cold to 15° F

Soil drainage

Fast, Medium

Soil description

Tolerates both heavy and sandy soils.
Soil PH: 6.0 - 8.0

Propagation

For propagating by seed: Hot water treatment.

Site type

Rocky, dry slopes below 4, 500 ft. most often along the coastal side of the mountains, frequently on north facing aspect, from Humboldt County to San Diego

Plant communities

Chaparral, Foothill Woodland, Yellow Pine Forest

Purple Sage (Salvia leucophylla), Sticky Monkeyflower (Diplacus aurantiacus), California Sagebrush (Artemisia californica), Deerweed (Acmispon glaber), Brittlebush (Encelia spp.), Sage (Salvia spp.), Manzanita (Arctostaphylos spp.), Oaks (Quercus spp.), Lodgepole Pine (Pinus contorta), Ponderosa Pine (Pinus ponderosa), Red Fir (Abies magnifica), Yucca species, native grasses, and Dudleya species

Bats
Caterpillars
Butterflies

Butterflies and moths supported

4 confirmed and 89 likely

Confirmed Likely

Chionodes occidentella

Duskywing

Erynnis afranius

Pacuvius Duskywing

Erynnis pacuvius

Recurvaria francisca