Most purchased garden trellises are a lattice made of wood or vinyl. They come in single panels that are ready for installation. Deciding what supports to use and how to hang the trellis depends on the use of the trellis. Trellises meant for lightweight, decorative plants, such as morning glory, only require minimal staking to remain upright, while those holding a heavy vegetable crop require sturdy posts. If you are using the trellis as a decorative or shade item, the options are the same as those for lightweight plants.
Choose the area for your trellis. Prepare the garden bed by tilling and adding any required soil amendments before hanging the trellis.
Measure the width of the trellis panel. Ideally, hanging posts should be spaced every 4 feet. Plan to space them closer if your trellis panel is narrower.
Mark where each support post goes in the garden bed with small wooden stakes. Dig a hole for each post at the stake markings.
Set your posts into the holes. Bury them 10 inches for lightweight plants or shade structures or 1- to 1 1/2-feet deep for heavy plants. Backfill the soil into the hole around the post and pack it in place firmly.
Place your trellis panel against the two posts. Nail the trellis to the posts, spacing the nails 6 inches apart to ensure that the trellis is held securely. Alternately, screw the trellis to the posts with an electric screwdriver.