Growing Berries in Your Backyard
Figure 16.3. See more detail in pdf linked, below.
Raspberries generally require a structure to hold the canes upright. In the hedgerow system canes are supported by wires that hold the canes upright and within the row. A four-wire trellis system, which uses two high and two low wires attached to the outside ends of 18 inch crossarms, is usually best. Heavy posts (4" X 4") are used to hold the crossarms. The two upper wires are placed 5 to 6 feet above the ground, and the two lower wires are placed approximately 30 inches above the ground. The posts are placed 15 feet apart in the row. This trellis system provides good separation of fruiting canes and protects primocanes, which then grow up the middle. Strong galvanized wire (Number 10 or 12) should be used for strength and durability. The trellis should be installed at planting time.