Blackberry varieties fall into two categories: erect canes and trailing vines. Growing conditions in the West favor the trailing types, according to The New Sunset Western Garden Book. Blackberry cultivation presents challenges in the form of diseases, insect pests, soil conditions, water needs--and sharp thorns. On the other hand, blackberries rank highest by far, when compared with all other berries and grapes, in the production of anthocyanins, antioxidant compounds derived from the berries' pigment.
Fruit does not appear until the second year after planting. Trailing varieties must be supported on trellis systems set up in the field. Paul Vossen of the University of California at Davis Extension Service advises that erect cane plants also be trellised to keep the rows neater and facilitate harvesting. To provide good drainage and aeration, plant blackberries in sandy or loamy soil. Consistent moisture is a necessity, but do not allow water to stand and rot the roots. Because blackberries are susceptible to verticillium wilt and other viruses carried in the soil, do not plant them on the same ground where tomatoes, potatoes or other members of the nightshade family have grown in the previous three years.
"Arapaho" and "Black Satin" top the list of cane blackberries that can grow without support. Summer bloomers, both are approved for USDA Zones 7-9. Each has the added benefit of being thornless and disease-resistant. "Chester," which blooms in late summer and early fall, is also thornless and described as vigorous and productive. Although bearing large thorns, "Darrow" boasts large fruit produced over a long harvest season.
Several of the vine types have been dubbed by their variety names combined with "berry." That is the case with the widely grown "Boysen" and "Logan" varieties. Boysenberries began with a plant on the abandoned farm of Rudolph Boysen. His neighbors at Knott's Berry Farm transplanted some of the vines in 1923 and named them for Boysen. Thus, the Knott's empire was based on this variety. "Marion" and "Olallie" also enjoy popularity among the trailers.
Improvements in the Newest Blackberries
Plants certified as free of viruses are now easily attainable. Most of the latest varieties have no thorns, although some growers say the thorny ones are the sweetest. "Triple Crown," an erect cane for USDA Zones 5-9, rated high in taste tests, as did a similar variety, "Navaho." An early summer producer, "Rosborough," was developed by Texas A&M; University for the warmer 7-10 zones.
- The New Sunset Western Garden Book; Kathleen Norris Brenzel
- University of California at Davis Extension: Growing Blackberries in California
- Mother Earth News: Enjoy Fresh Blackberries
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