Not that kind of grass? Although that would be interesting. I mean actually rolling on grass. I was just thinking it would be cool to train grappling outside in a park the early evening, just thought it would be a refreshing change from the hot room we're all acoustomed to. If anyone has tried it i'm curious how it went. I'm also wondering specifically how it would fly in central park in manhattan. How cool would it be if you were walking through the park and saw a group of people practicing bjj?