Triple Crown Thornless Blackberry
Improved Blackberry Plants for Thornless Harvesting
If you’ve ever picked wild blackberries, you may have come home with scratches on your arms and torn clothing, which made berry-picking an unpleasant adventure. But there’s a world of difference between wild blackberries and Triple Crown Thornless Blackberry (Rubus ‘Triple Crown’), notably the lack of sharp thorns! As a cultivated blackberry, introduced by the USDA in 1996, Triple Crown Thornless is also tastier, and it has smaller seeds than its wild berry relatives.
Triple the Benefits
Triple Crown Blackberry is so-named because of its three crowning characteristics:
1. Sweet flavor. The berries are bred to be larger than many blackberry types, without compromising sweetness for size.
2. Large harvests. University research shows typical yields of 10 to 20 quarts of berries per mature plant.
3. Vigorous plants. Blackberry plants are classified as brambles, which have canes that bear the fruit. Triple Crown Blackberry has strong, thick canes that are able to support the plant’s abundant harvests.
Blackberry Cultural Needs
• Sun. Plants will tolerate partial shade, but they perform best in full sun (at least 6 hours each day).
• Soil. The soil must drain well; plant in raised beds where drainage is a problem. A soil pH level between 6.0 and 6.8 is optimal.
• Water. Give new plants plenty of water during their first year of establishment. When fruit is developing on the canes, give each plant 2 gallons of water each day. During non-fruiting times of the year, 1 inch of water per week is sufficient.
• Fertilizer. Fertilize based on soil-test recommendations. In the absence of a soil test, apply 1 cup of 13-13-13 fertilizer (or organic equivalent) around each plant, one month after planting. In subsequent years, apply 2 cups of 13-13-13 fertilizer (or organic equivalent) around each plant, once in spring.
• Pollination. Triple Crown Blackberry is self-fruitful, which means you don’t need to grow more than one plant to ensure cross-pollination. However, you’ll enjoy larger harvests of sweet berries if you grow multiple plants.
Trellising and Pruning
Each cane on Triple Crown Blackberry plants grows for two years -- the first year’s growth is called primocane, which doesn’t bear fruit, and the second year’s growth is called floricane, which flowers and produces the berries in summer. Classified as a semi-erect blackberry, Triple Crown’s growth is mostly upright. Because of the large harvests, plants are best supported by training them to a 5-foot-tall fan-shaped trellis and following these simple pruning tips:
• As plants grow, tie 6 to 8 of the canes to the trellis, fanning them out.
• When the canes grow taller than the top of the trellis, cut off the tips to prompt lateral growth for bigger harvests the following year.
• During the dormant season (late winter), remove the canes that produced berries the previous summer by cutting them to the ground. Cut back the remaining canes to 24 inches – these are the ones that will bear fruit during the upcoming summer – and tie them at intervals to the trellis as they grow.