A trellis provides more gardening space and adds an element of architecture to a garden. Although many gardeners build a trellis for a place on a fence, wall or garden, you can build a trellis to fit on your deck. This type of a trellis provides easy access to your plants--particularly vegetables, fruits or herbs. You can install it in full sun or partial shade by securing it to the house wall on the deck or on the side closest to the garden. When building the trellis, make sure to check the area's dimensions where you want to install the trellis, and measure the boards accordingly. A popular size is 4 feet by 4 1/2 feet.
Lay five 4 1/2-foot boards down vertically on a flat surface. Line up the edges evenly and create a box shape by spacing the boards about 3 1/2 to 4 inches apart. This is the deck trellis' main structure.
Pick up a board from the set of 4 1/2-foot boards. Measure 3 1/2 to 4 inches down from the top edge of the boards already lying on the ground. Lay one of the boards that are 4 1/2 ft long horizontally across at this measurement. Keep this board centered and even with the edges.
Repeat this process of measuring down and laying another horizontal board until you run out of boards and are at the bottom of the lattice. It should resemble a tic-tac-toe board. Keep all edges even and the boards centered.
Nail each intersection where the vertical and horizontal boards meet. After you finish all intersections on the front, flip the trellis over carefully and repeat the process of nailing on the back of the trellis, if you feel it needs more stability.
Stain or paint the trellis, if desired, with a design, stencil or to match your home decor or garden. Allow the trellis to dry for a couple of days.
Secure the trellis to your deck by either using trellis ties or hooks. If you are hanging the trellis on the side of the house, use the hooks secured into the wall with the drill and bit. If you want it secured to the side of the deck so it covers an open area that overlooks the garden, use the trellis ties to secure it to the nearest structural post or to an eave.