Here's a few photos of our trellis. The posts are 6x6 and 8 feet long. We set them 3ft in the ground leaving us with a 5 foot post. We strung cable in three rows 15 inches apart. We are putting matching wire rows on the other side too, but our snippers petered out. It will be finished by this weekend. I misspoke when I said it was twenty feet of raspberries...its actually 30ft!!! yum yum
The thought is that the wire is strung on the outside of the row of raspberries. So when the plants grow, we can hang the canes over the wires for support. Its also nice because you can access the plants from both sides!