The word green comes from the Middle English and Old English word grene, which, like the German word grün, has the same root as the words grass and grow.
According to the Turfgrass Extension and Outreach program at UIUC, every mowing should remove one third of the grass blade's height. [http://what-if.xkcd.com/70/]
Grass conserves water and cleans the air. Grass traps water and reduces soil erosion. The average grassed yard can absorb more than 22.7 m3 (6,000 gallons) of rainwater. [aitc.oregonstate.edu]
