I made these trellises last winter, but we waited until spring to install them.
The stock is 3/4″ clear red cedar, ripped and planed to 1 5/8″ strips. I applied a coat of oil base exterior primer to the wide cedar boards before I ripped them, then the edges were primed, and each board received two coats of white exterior paint.
The client requested that the units be 4′ x 8′, the size of my work table. I attached vertical stops around the edges of the table and laid out the outside frames tight to the stops. After marking the spacing, I cut the lattice at 45 degrees to fit snugly and attached with trim-head stainless steel screws.
After assembling the lattice to the frames, I installed the caps and casings. The units are attached to 1 1/4″ heavy-duty angle iron, painted with white Rustoleum, and driven 3′ into the ground.