Most people do not realize the environmental benefits of lawns. Lawns are known to cool the air, reduce soil erosion, remove dust and pollutants (including CO2) from the air, reduce run-off of water and pollutants, create oxygen for humans, and improve soils over time by supplying organic matter. Lawns are also important aesthetically and have been shown to improve human well-being. However, to be 100 percent environmentally friendly, we could never fertilize or water our lawns and only mow with a self-propelled reel mower. Or, we could get rid of our lawn altogether. Neither of these options is particularly appealing for most people. We can, however, have a high quality lawn and reduce our impact on the environment by doing some very simple things at the right times of the year. The following guide will walk you through a series of steps that are important for keeping your lawn looking thick and healthy and at the same time reducing pests and the need for chemicals and other inputs.