How would you construct a trellis for red raspberries?
There are several different trellis systems. A two-wire permanent trellis is commonly used to support raspberries in the home garden. Its construction requires wooden posts, No.12 or 14 galvanized wire, and 2- by 4-inch lumber. The wooden posts should be 3 to 5 inches in diameter and 6 to 8 feet long. Posts should be set 2 to 3 feet into the ground and spaced 15 to 20 feet apart. Near the top of each post, nail or bolt a 24- to 30-inch-long crosspiece. Then run or attach the galvanized wire through the ends of each crosspiece and down the entire length of the row. The two wires should be spaced about 18 to 24 inches apart and positioned 3 to 4 feet above the ground.
A temporary trellis may be constructed of posts and twine. Set the posts approximately 15 feet part. The canes are supported by running twine between the posts. This temporary structure is most suitable for fall-bearing red raspberries grown exclusively for the fall crop.