Choose the trellis type and size
Gather materials: wood, metal, or PVC; screws or nails; concrete; tools
Measure and mark the installation area
Cut the frame pieces to length
Assemble the outer frame
Add vertical, horizontal, or diagonal support slats
Secure all joints tightly
Sand rough edges if using wood
Apply weatherproof sealant or paint if desired
Dig post holes if the trellis will be freestanding
Set posts in concrete and let them cure
Attach the trellis panel to the posts or wall
Check that the trellis is level and stable
Train plants onto the trellis with ties or clips