Cultivate "superfood" blackberries

By Denise Ruttan

When you're planning this year's garden, don't overlook one of the unsung heroes of the fruit world – the blackberry.

"Many people don't want to plant blackberries in their yard because they think it's an invasive weed," said Bernadine Strik, a berry crops specialist with the Oregon State University Extension Service. “But they're actually thinking of the Himalaya blackberry,

which is an invasive weed introduced to Oregon in the late 1800s that is very difficult to kill.”

Cultivated varieties do not become weeds like the wild plant growing along Oregon's roadsides, Strik said. Marion, commonly known as "marionberry," is possibly the state's most famous cultivated blackberry – named after Oregon’s Marion County, where much of the world's supply is still grown.

Cultivated blackberries are actually one of the easiest, tastiest and most nutritious fruits to grow at home, Strik explained. Blackberries, often called a "superfood" for their nutrient-rich qualities, have high levels of antioxidants and are packed with vitamin C and fiber. Plus, cultivated blackberries are much more aromatic, flavorful and contain smaller seeds than their wild relatives, she added.

Trailing blackberry varieties can grow vigorously, so it's essential to manage them by training them on a trellis and pruning them, Strik said. Basically, the term "trailing" means it is a type of blackberry that requires a trellis for support.

Strik recommended the blackberry varieties below for gardeners. These cultivars grow best in western Oregon, as trailing varieties can be sensitive to cold, Strik advised.  

* Columbia Star: This variety is not available in most retail nurseries yet, but gardeners could look forward to seeing it in a couple of years if it is popular with commercial growers, Strik said. This thornless blackberry has large-sized, uniform-shaped fruit and outstanding flavor. It produces fruit in July.

* Black Diamond: This thornless variety has less vigor than most and produces fruit with a good flavor in July.

* Obsidian: This thorny blackberry produces large-sized fruit in starting in late June. Excellent flavor.

* Marion: Often called marionberry, this thorny blackberry produces medium-sized, soft, dark purple fruit with excellent flavor.

* Boysen: Often called boysenberry, this thorny blackberry produces large-sized, purple fruit with a unique and very good flavor.

* Triple Crown: This thornless blackberry produces fruit in late August and September. Its medium- to large-sized fruit is black, glossy and has good flavor. But note that it is prone to sunburn.

Late March and April are the best times to plant blackberries, said Strik. Remember to keep the plants free of weeds. You can do this by placing landscape fabric around the base of the plant, provided you use drip irrigation. Or you could apply well-composted mulch to reduce weeds. Train new canes in the plant's first year by tying them to a trellis, advised Strik, a professor in OSU's College of Agricultural Sciences.

The plants won't bear fruit in their first year, but they will produce fruit in the second year and become mature in the third year, Strik said. They will produce fruit every year after the third year. Most of the fruit ripens from June to August.

For more information about raising blackberries, see the recently updated OSU Extension Service publication "Blackberry Cultivars for Oregon". Also see the OSU Extension publication "Growing Blackberries in Your Home Garden" .

Image above: Photo by Stephen Ward. Cultivated blackberries, which are not weeds, have a more aromatic flavor and smaller seeds than the wild Himalayan blackberry, which is an invasive weed. Many cultivated varieties, such as Marion (the “marionberry”) and Obsidian, are easy to grow at home.