Google "hoop house". Instead of perfectly clear plastic, use the sort that is a little hard to see through but lets light in.
Or build a lean-to type structure with the south wall sheathed in translucent corrugated fiberglass.
A solid building with a lock on the door offers better protection from prying eyes than a greenhouse sheathed in plastic sheeting. It might also be different in terms of rules for a search, but you would have to look that up.