The trellis directly in front of the slab is made of cattle panel, which I've used a lot throughout the garden for plant supports, including an arbor for a climbing rose. Cattle panel is fencing made of 1/4 inch steel rods welded together into very sturdy 4 foot by 20 foot sections. It can be cut with heavy-duty bolt cutters and bent into various shapes - by standing on it and forcing it!