Rubus 'Columbia Giant' Blackberry cultivar is valued not only for fruit production but also for ornamental purposes, fitting beautifully into edible landscapes and mixed beds. A thornless trailing blackberry cultivar, the plant grows up to 6 feet in height on a trellis and bears fruit 1 to 2 years after planting.
An early mid-season variety, Rubus 'Columbia Giant' Blackberry produces high yields, higher than 'Marion' blackberries, of 10 to 15 pounds of very large, well-formed, attractive blackberries. The berries are giantup to 3 inches longand have a uniform conical shape. They are firm, juicy fruits with a well-balanced sweet flavor that has just a touch of tartness. The plant is hardy to -10 degrees Fahrenheit.
Easy to grow, Rubus 'Columbia Giant' Blackberry prefers full sun and moist, well-drained soil in a location protected from wind. Add organic content to enrich the soil; fertilize in early spring with an all-purpose fertilizer, such as 10-10-10 or a 16-16-8; and keep well-watered, mulching around the base to conserve moisture and kill weeds. The plant is pest and disease resistant.
Blackberries are self-pollinating, so multiple plants are unnecessary for fruit production; however, planting two or more varieties with similar bloom times encourages cross-pollination, producing larger yields of larger berries. Planting early, mid-season, and late-fruiting varieties extends the blackberry season from early June to the end of the summer.
