The Biggest Berries
Jason planted several rows of 'Kiowa' blackberries four years ago and has trained them to grow on a trellis. The upright plants do have thorny canes, but they produce enormous fruit. In fact, they have the largest of any blackberry. They can grow 8 to 10 times bigger than wild berries.
Training on a Trellis
Jason sets plants out 5 feet apart in a sunny location. A post-and-wire trellis supports the vigorous growers. Two wires run horizontally between the posts. The first wire is 24 inches off the ground, and the second is 48 inches high. Once the plants begin to grow, Jason selects the two strongest canes to train and cuts the rest to the ground.
Throughout the summer, he prunes out any new canes that appear so they don't take energy away from berry production. He allows the first cane to grow 2 or 3 inches above the 24-inch-high wire, and then cuts it off an inch below the wire. Two side shoots will branch out below where the stem was cut. These are then trained to run along the wire. The second cane is allowed to grow a couple of inches above the 48-inch wire; then it's cut an inch below that wire. The two side shoots that appear are trained to grow horizontally on the upper wire. As the side shoots lengthen, they are wrapped around the wires and loosely held there using plastic ties or twine. While training the thorny selections, you will definitely need a pair of leather gloves.
'Arapaho' and 'Navaho' are two outstanding thornless selections that can be trained this way and are much easier to work with. You can also get plants to grow on an existing fence or even espalier them against a wall. A family of four will need to grow only five or six plants to have plenty of fresh produce.