Trailing blackberries can be best described as living tripwires; that is, they are trailing woody vines to 6 m (20 ft.) long.
They arise from rather small woody roots that lead to long, arching, thin stems that scramble over whatever purchase they find. The vines often tangle into half-meter-deep (20 in.) masses over large areas. As with many blackberries, shoot tips root strongly in the fall, expanding the domain of the species. Well-toothed evergreen leaves of one to three leaflets are widely spaced along the stems. Slender prickles line the bluish stems and leaf stalks. These prickles are fine enough that they don’t gouge out chunks of flesh as does Himalayan blackberry (Rubus discolor), but I have learned well that they can lodge under the skin surface and cause minor irritation for several days. Hairy and prickly clusters of bright white flowers rise upwards from the horizontal stems. Male and female flowers occur on separate plants, an important point to keep in mind when growing trailing blackberries for fruit. Stamen-bearing male flowers are 2 to 4 cm (1 to 11/2 in.) wide with five narrow pointed petals.
The female flowers are slightly smaller, but their petals are wider. The shiny black fruit is an elongate blackberry about as big as the tip of your small finger. Flowers appear as early as April on south Vancouver Island and the sweet juicy fruits follow by mid-summer. Trailing blackberries thrive on disturbed sites such as old pastures and roadsides, growing well particularly after fire. They grow in and at the edge of shrubby thickets and in forest openings, too. They are one of the last native species to remain in sites where most native species have been removed through repeated clearing. In British Columbia these blackberries grow on Vancouver Island, on the adjacent mainland into the lower Fraser River Canyon and, notably, at a site in the Kootenays. The distribution range extends at low to middle elevations south to California and eastward to central Idaho.
Trailing blackberry found wide use among British Columbia’s coastal First Nations. Berries were eaten fresh or mashed for drying into cakes. Older red leaves, considered the most flavourful, were picked by some coastal peoples and boiled into a tasty tea. Medicine from leaves and roots treated ailments from dysentery to sores in the mouth. The vines supported and covered various types of food in steaming pits, and berry juice was used as a purple skin stain. Today, trailing blackberry leaves are used in several commercial herbal tea mixes. The plant’s most important contribution is as one of the parents of the delicious loganberry, which arose as a chance cross in Judge Logan’s garden in California.
In suitable coastal climates, blackberries are extremely easy to grow. Once established in a garden they may even need to be held in check. They are readily propagated from the rooted tips, which can be harvested and planted in moist fall and winter months. Choose a sunny to partly shaded, well-drained site and work the soil 10 cm (4 in.) deep. Plant your rooted stem cutting soon after digging it. Before selecting plants for propagation, note whether they are male or female and plant at least one male with the females. (If you are growing the plants for tea, the sex of the plant does not matter.) strongly suggest training the vines on a trellis or wires for ease of maintenance and harvest, and control of spread. Plants are easily propagated from seed, too, and if you grow other brambles in your garden, I can vouch that some delicious natural fruit crosses may result.
As well as being a great source of tea and wild fruit, the scrambling stems form excellent groundcover over eroding slopes and restrain human foot traffic. Food, drink, groundcover and easy to grow…one could hardly ask for more from a native species. The following plant is hardy to the zone number indicated: Rubus ursinus (trailing blackberry) – zones 5-6 An expert on native plants, Richard Hebda is curator of Botany and Earth History at the Royal British Columbia Museum in Victoria. Gardenwise Spring 2005