Correctomundo, Paul W. Right off the bat, darn it. Retractable (woven) roof; designed to accommodate a bit of snow, but you don’t want to leave it in place for any more than that. This was at the Merrifield Garden Center in Alexandria. Winter of 2011. I was there speaking to the fabulous Fairfax Master Gardeners and trainees (SandyG, I swear you were there).
The snow cover just seemed kind of odd/neat, because the roof was closed back up by the time I walked in.