Headed to the hardware store to puppy proof the yard?

I'm getting a lab puppy in 2 weeks and I have an area about 3' X 20' where we had some landscaping done that the dog cannot touch. I was considering getting some chicken wire and laying it across said area. But if there is a certain type of mulch I can use I'd rather do that. Does anybody have any experience with any of these methods or any better suggestions.