Updated: Oct 18, 2021
California has everything, even its own rose. No, it is not a fancy multi-petaled cut flower coveted by lovers, but it certainly has charm and useful benefits. Its pink blooms are simple, only five petals, opening in clusters atop the limbs. They are tempting to touch, but do not forget their stems are covered in equally small thorns.
I have been seeing more California rose plantings in ornamental landscapes. In Berkeley, a green stormwater infrastructure treatment was filled with these thorny stems. They will indeed thrive in such conditions, tolerating dry and wet soils, but the thorns (sorry for the thorn fixation) make trash and weed clean up treacherous without long gloves. In the City of San Jose, we have several landscapes that include this rose; a riparian habitat mitigation, meaning native species were planted in support of local habitat; and high on Communications Hill, a major subdivision, where I captured these photos.
There are considerable benefits to planting R. californica. While other native species tend to be persnickety about when and how much water they receive, this one is clearly quite adaptable. Too dry, and it remains more shrubby, but in a reasonably moist condition will spread and establish as a bramble or thicket, lending itself to barriers. The flowers are great for pollinators including California's native bee population, butterflies, and other beneficial insects. A long bloom period, from mid-spring into early autumn, is followed by showy, edible rose hips. In shade, it becomes delicate and almost vining, but in full sun will remain dense. Adaptable, hardy, and a multitude of benefits lends the California rose to many landscape design opportunities...despite thorns.
Point Lobos State Historic Park
Botanical Name: Rosa californica
Rosa: Latin for rose
Californica: Associated with California
Common Name: California rose
Family Name: Rosaceae
Origin: Native; throughout California, southern Oregon, northern Baja California
Positioning: Middle ground, perennial or seasonal streambanks or other intermittent moist areas
Garden Themes: Native, pollinator, cottage, riparian, woodland, rain
Uses: Barrier, mass, border, specimen, slope stabilization/erosion control, revegetation, screen, green stormwater infrastructure
Type: Semi-evergreen shrub
Form: Erect, spreading
Size: Highly variable based on location: '3 to 8' tall and spreading
Outstanding Feature(s): Fall color; rapid growth
Stems: Red-brown to green (when young); thorns may be few to abundant
Type: Odd pinnately compound
Shape: Ovate to elliptic leaflets, usually 5-7 per leaf
Margin: Serrate to biserrate
Color: Medium to light green
Flower: Spring to Autumn. Showy, small, simple with short stem but in clusters from 3 to 30 flowers, light pink with prominent yellow stamens.
Fruit: Autumn. Clusters of small but showy red fruit or hips, edible.
cultural requirements, tolerances & problems
Sunset Zones: 4-24
USDA Zones: 5-11
Light: Full sun to partial shade
WUCOLS SF Bay Area Hydro Zone: Low
Texture: Sand, loam, clay, well composted is best
Moisture Retention: Well-drained. Accepts periods of dryness or sogginess.
pH: Acidic to alkaline
Problems: Under right conditions, may developed into a thorny thicket difficult to control.
Branch Strength: N/A
Insects: Grape white fly
Disease: Powdery mildew
The United States Department of Agriculture's Natural Resources Conservation Services references Chumash people eating ripe rose hips raw, right from the shrubs. Other First People uses noted prepared hips and flower petals used for medicinal purposes, stems for basketry.
citations & attributions
Bayton, R. (2019). The Royal Horticultural Society's the Gardener's Botanical: An Encyclopedia of Latin Plant Names. London: Mitchell Beazley.
Calscape. "California Rose." California Native Plant Society, Sacramento. Accessed on October 2, 2021, from https://calscape.org/Rosa-californica-(California-Wildrose).
Ertter, B., & Lewis, W. H. (2008). NEW ROSA (ROSACEAE) IN CALIFORNIA AND OREGON. Madroño, 55(2), 170–177. http://www.jstor.org/stable/41425776
Smither-Kopperl, M.L. 2021. Plant Guide for California wildrose (Rosa californica). USDA-Natural Resources Conservation Service, Lockeford Plant Materials Center. Lockeford, CA 95237. Accessed on October 7, 2021, from https://www.nrcs.usda.gov/Internet/FSE_PLANTMATERIALS/publications/capmcpg13761.pdf.
Taxon Report. "Rosa californica Cham. & Schltdl." Calflora, Berkeley. Accessed on October 8, 2021, from https://www.calflora.org/app/taxon?crn=7179.
Water Use Classification of Landscape Species. "WUCOLS IV Plant List." University of California, Division of Agriculture and Natural Resources, Davis. Accessed on October 7, 2021.
All photos by TELCS.