Where a trellis is used, the posts and string are removed and replaced after mowing. We recommend applying a lime sulfur spray in mid-March and mowing the plants within several days of the spray. Prior to mowing, posts and string are removed and then replaced after mowing. Mowing close to the ground is recommended. Thornless Blackberry Production System 5.
Thornless blackberries are vigorous and require a trellis.
Primocanes are tied to two or three wires in March. Wires are fastened to treated posts at three feet and at five feet. The vigorous main shoot may be allowed to grow along the top wire either to the next plant or past the next plant. A single-T trellis has two horizontal wires at five to six feet from the ground. A double-T trellis has one set of two horizontal wires at four feet and another at six feet from the ground.