Don't Close-Crop Your Lawn: One secret to a greener lawn? Let it grow longer.
Different types of grass have different optimum heights, so it's not a bad idea to consult gardening books or speak with the staff at your local nursery to determine what's best for your yard, and then aim for the upper range. However, Paul Tukey, author of The Organic Lawn Care Manual ($13.50 at amazon.com ), points out that cutting grass to three- or four-inches-tall can reduce evaporation by 70% to 80%. Don't forget to keep cutting blades sharp, as that prevents the tearing that is hard on plant tissue.