Rubus ursinus (California Blackberry)

Rubus ursinus (California Blackberry) is a trailing or climbing shrub with long canes abundantly armed with tiny, slender, hooked spines. The slightly prickly, dark green leaves grow in leaflets of three and are lighter green on the underside. The terminal leaf has three lobes, each pointed and toothed. From early spring to mid-summer, clusters of 2-15 white or pink flowers, 1.5 in. across (4 cm), develop at the ends of the fruiting canes. The blossoms give way to an abundance of oblong or conical, edible, red berries which mature to shiny black. The berries are sweet and flavorful and great for fresh eating, baking, or freezing. California Blackberry is dioecious, with separate male and female plants. Only female plants produce fruit. California Blackberry provides food and cover for many wildlife species. Blackberries are eaten by many bird species, including the ruffed grouse, northern bobwhite, sharp-tailed grouse, or California quail. Mammals such as coyotes, opossums, squirrels, and black bears feast on the berries too. The dense thickets of blackberries form good nesting sites for many small birds. Unlike other brambles, California Blackberry does not spread by underground rhizomes, but via its arching canes that root wherever they touch the ground, enabling the plant to spread vegetatively and form larger clonal colonies. This vigorous spreader needs cool temperatures and high amounts of moisture to set large fruit. Native to a large part of western North America from Baja to Canada and from the coast to the Rocky Mountains, Rubus ursinus occurs across a wide range of sites from warm, open areas to dense woodlands. It is particularly common in prairies, clearings, waste places, and canyons. California blackberry frequently assumes prominence on sites that have been burned or logged. The commercially grown loganberry, youngberry, and boysenberry were originally derived from this species. California Blackberry can be used as a groundcover, hedge, or in a wildlife garden. Be careful: the thorns make picking, weeding, pruning, and other maintenance activities quite unpleasant.

• Grows up to 2-6 ft. tall (60-180 cm) and 4-6 ft. wide (120-180 cm).
• Performs best in full sun to full shade in moist soils. This plant tolerates a wide range of soil texture and pH but requires adequate soil moisture for good growth. California blackberry appears to be tolerant of periodic flooding by brackish or fresh water.
• Prune during winter dormancy to shape and control spread. Remove any canes damaged by winter and thin, as needed, the remaining canes. Make sure to wear thick gloves and protective clothing to try to avoid, or at least minimize, injury from the thorns.
• No serious disease issues.
• Propagate from stem cuttings.
• California Blackberry grows from British Columbia to northern California and eastward to central Idaho. It is particularly common from the Cascades to the Pacific Coast. California Blackberry extends through southern California into Mexico.