The marionberry is a vigorously growing trailing vine, usually producing just a few canes up to 20 feet long. The vines have many large spines, and the fruiting laterals are long and strong, producing many berries. The berry is glossy and, as with many blackberries, appears black on the plant, but turns a deep, dark purple when frozen and thawed. It is medium in size and tends to be conical, longer than it is wide. The berry has a somewhat tart flavor, fairly earthy with traces of sweetness. It is larger, sweeter and juicier than the 'Evergreen' blackberry. The relative complexity of its flavor has led to a marketing label as the "Cabernet of Blackberries". The more powerful flavor of the marionberry has led to it dominating current blackberry production.
Development and cultivation
The marionberry was developed by the USDA Agricultural Research Service at Oregon State University in Corvallis, Oregon. It was bred by George F. Waldo, as a mix between the small, flavorful 'Chehalem' berry and the larger, better-producing 'Olallie' berry. Both the 'Chehalem' and 'Olallie' berries are caneberry hybrids, as well. Waldo made the initial cross in 1945, selected it as OSC 928 in 1948 in Corvallis, and tested it in Marion County and elsewhere in the Willamette Valley. The berry was released in 1956 under the name Marion, after the county where it was tested extensively. Oregon produces between 28 million and 33 million pounds annually, with Marion County and the Willamette Valley collectively accounting for over 90% of current production. The marionberry is well adapted to the mild, maritime Oregon climate, with its mild rains and warm summers. The berries ripen throughout late spring and early summer. The harvesting season is typically between July 10 and August 10, with a single acre producing up to six tons in a harvest. There is a hybrid variety with Boysenberry in Australia called Silvanberry. Classed under the blackberry family, Sylvanberry plants have many characteristics commonly found among other blackberry varieties. These plants are long living perennials, hardy and cold tolerant, easy to grow, and productive spreaders.
As of February 2009, the Oregon Legislature has proposed to make the marionberry the official state berry, under House Joint Resolution 11. Although supported by all 90 legislators, the resolution has been delayed by the Oregon Raspberry and Blackberry Commission, as a Washington County farmer named Larry Duyck has objected. Duyck grows the Kotata blackberry, as opposed to the marionberry. He suggests, as the marionberry is already the most produced variety of blackberry, official recognition would boost its sales even more and hurt other varieties. Most legislators have agreed not to press the issue.