CORVALLIS, Ore. – There's more to blackberries than the tangled, prickly masses you find growing aggressive and wild on roads and pathways.
In fact, Oregon gardeners can enjoy home-grown blackberries that are known around the world for their flavor and quality thanks to the breeding efforts of Oregon State University Extension Service and the USDA Agricultural Research Service.
A new publication from OSU Extension gives details on how to start growing tasty, improved blackberries – many without thorns – that will stay productive for 15 to 20 years. "We have an ideal climate with warm summer days and cool nights, so our berries reach peak flavor and quality," said Bernadine Strik, Extension berry crops professor at OSU and author of the publication.
Publication EC 1303 may be found online at "Growing Blackberries in Your Home Garden."
Commercially, Oregon growers produce the highest yield of blackberries anywhere, Strik said, and Oregon is second only to Serbia for the amount of blackberries sold worldwide.
What's the difference between a blackberry and a raspberry? They are distinguishable by where their white core remains when picked. The blackberry core remains with the berry and is part of what you eat. The raspberry core remains with the plant, leaving an opening in the fruit.
The three main types of blackberries are trailing, erect and semi-erect. Trailing berries are considered excellent, with good aroma and small seeds, but are the least cold-hardy. Trailing cultivars (varieties) include Marion, Cascade, Santiam, Black Diamond, Obsidian, Thornless Evergreen, Boysen, and Logan. Erect and semi-erect berries need summer and winter pruning and are glossy and firm with larger seeds than the trailing types. Common cultivars in these groups include Navaho and Triple Crown.
Blackberries produce best in full sun but will tolerate partial shade, Strik said. "All types are self-fruitful so you need only one cultivar for pollination and fruit production," she said. The fruiting season ranges from mid-June to September, depending on the variety, and no fruit is produced the first year.
Trailing blackberries grow well west of the Cascades, and you can grow them in colder areas with low winter rainfall if you leave the canes on the ground and mulch them in winter.
"It's best to purchase certified disease-free plants from a nursery, "she said. "Plants from a neighbor could introduce root-rot organisms, viruses or other pests into your garden."
Plant as early as you can work the soil in the spring, Strik advises. Almost any soil type is suitable as long as drainage is good. Blackberries grow best when the soil pH is between 5.5 and 7.
"It's advisable to trellis blackberries,” she said. “You can grow them without support but trellises help prevent cane breakage from wind. A trellis also provides a neater planting and makes cultivation and harvesting easier."
Details on planting, fertilizing, irrigation, pruning and weed management are available in the newly revised publication.
More information on varieties can be found in the OSU Extension publication EC 1617: Blackberry Cultivars for Oregon.