Vines attached directly to wood siding can cause moisture damage and even pull the wood away from the house. Many vines attach themselves to structures with tiny holdfasts or rootlets that enter small cracks and can pull down the siding. Other vines use twining stems to attach to structures, but wood siding offers no surface for twining. The best option is to install a trellis system that makes it look as though the vines grow directly on the siding. This leaves clearance for evaporation and air circulation while providing a safe, sturdy structure to support the vines.
1 Run an electronic stud finder along the wood-sided exterior wall and use chalk to mark the location of all studs, which should be spaced 16 to 24 inches apart on center. As you glide the stud finder over the wood, the small machine detects the density and beeps or flashes a small indicator light when it hovers over a stud. You must find the studs because they are better able to support the weight of a trellis covered with vines. A heavy trellis could pull down the siding without proper anchoring.
2 Cut 2-by-4 boards to the desired height for the trellis, if needed, using a circular saw or compound miter saw. Boards generally measure 8 feet long, but the length varies, so cutting isn't necessary if the board length is equal to the desired trellis height.
3 Apply a 1/4-inch bead of construction adhesive along the long narrow edge of a 2-by-4. Line up the board with one of the wall stud marks; hold a level against the side to check the board for plumb. Push the board onto the wood siding and hold it tight for about 20 seconds until the adhesive bonds and sets. Enlist a helper so you can apply pressure over a greater portion of the board.
4 Attach additional 2-by-4s to the siding spaced about 4 feet apart. If the studs are spaced 16 inches apart on center, attach a 2-by-4 to every third stud mark; attach a board to every other stud if they are spaced 24 inches apart.
5 Drive 4-inch wood screws at an angle through the 2-by-4s and into the wall studs for extra strength. Install two screws on either side of the top and bottom of each board. You might need to drill pilot holes through the boards to make it easier to start the screws. Use a drill bit for the pilot holes that is one size smaller than the diameter of the screws.
6 Line up sheets of wood or plastic lattice with the studs you mounted to the exterior wall. Screw them into the studs, using 1- to 2-inch wood screws spaced 6 inches apart along the board height. Lattice comes in 4-by-8-foot sheets. You can attach a single panel vertically between two studs so the edges of two panels meet in the middle of a stud. Alternatively, install the lattice horizontally so that one sheet spans three studs and with two sheets stacked directly on top of each other.
7 Plant climbing vine plants in the ground about 1 foot out from the trellis. Follow the spacing required for the vine species you choose. Moonflower (Ipomoea alba, U.S. Department of Agriculture plant hardiness zones 10 through 12) grows only 3 to 6 feet wide, so you should space plants 3 feet apart. Sweet autumn clematis (Clematis terniflora, USDA zones 5 through 9) grows 15 to 30 feet wide, so each plant should be spaced 15 or more feet apart. Vines that have sparse growth with only a few vines might need to be cut back at planting to encourage branching.
8 Push the ends of vines in and out of the diamond-shaped grid for the first month or two to train the vines until they attach themselves to the trellis. If the vines don't stay woven in the trellis, tie them loosely with natural twine.
9 Cut back errant vines to control the size, shape and weight of the trellis. Check the back side of the trellis and clip any vines that touch or are growing toward the siding. Maintain the 4-inch gap between the wall and trellis so air can circulate and moisture in the vines doesn't rot the wood siding.