To me, I see the edges covered by the same kind of rubberized material used to cover the edges of car doors. I'd like to ask about the bottoms of the corrugated sections....IS there a bottom, or is it merely a landscape fabric beneath, or does the entire garden sit on a concrete pad, covered over with crushed stone for looks and proper drainage?

I'm sure that places like Lowes and The Home Depot sell the protective rubber covering the top edges. But, rolling a hem toward the inside will also accomplish the same thing, just not as neatly.

The edges appear to be covered by split garden hose. Sometimes the hose is adhered to the lip with construction adhesive.