When you want a trellis to support your vining plants, all you really need is a piece of lattice, wire mesh or any other paneling with lots of holes the plants can "grab" onto. It's possible to lean that paneling against a fence or building, creating a vertical -- and slightly leaning -- space for your plants to grow. If the paneling is thin or the conditions make it so the paneling won't stay in its leaning position, you'll have to brace it to the siding or fence. You can try a few methods to accomplish this.
Inspect the area where you want to lean the trellis. Determine whether the surface the trellis is leaning on is concrete, wood, metal fencing or some other material.
Measure the trellis' width using a tape measure. If your trellis panel is made of latticework or wire mesh, it may come as a 4-foot-by-8-foot panel.
Cut a 2-inch-by-4-inch piece of lumber to the length of the trellis' width.
Hold the this board along the wall at the height where the trellis will meet the wall.
Drill 2-inch screws through the 2-inch-by-4-inch board and into the wall, if the wall is wood or paneling that can be drilled through. If the surface is metal, stucco or something else, dig two holes in the ground a few inches short of the trellis' width, each 2 feet deep. Place 4-inch-by-4-inch boards, measured to 2 feet longer than the height of the trellis, into the holes. Fill the holes with quick-drying concrete and add a little water. Hold a level to the sides to ensure you've placed the boards level; adjust if needed. Allow the cement to dry for at least 20 minutes, and then drill through the 2-inch-by-4-inch board and into the top of each 4-inch by 4-inch post.
Drill 2-inch screws through the trellis paneling and into the top of the 2-inch by 4-inch horizontal board. If you're using wire mesh or some other type of metal for your trellis, place industrial staples over the sections of wire that touch the horizontal board and secure them to the board with a hammer.