Unless you're in the Great Plains and it's two feet high, a lawn is UNSUSTAINABLE.
I'm not saying to go out and tear yours up. I'm certainly not going to tear mine up, my wife wouldn't allow it.
But, I am saying, stop using grass and lawn imagery when you're promoting your Green products and services. It's going to backfire, and you'll wish you'd used some more accurate icon of sustainability. What would that be? Oh, I don't know. Use your imagination, and let me know if you think of something.