Enhancing our Environment Plants protect water quality. Proper landscaping reduces nitrate leaching from the soil into the water supply. Plants also reduce surface water runoff, keeping phosphorus and other pollutants out of our waterways and preventing septic system overload. Proper landscaping reduces soil erosion. A dense cover of plants and mulch holds soil in place, keeping sediment out of lakes, streams, stormdrains, and roads; and reducing flooding, mudslides, and duststorms. Plants improve air quality. One tree can remove 26 pounds of carbon dioxide from the atmosphere annually, equaling 11,000 miles of car emissions. Landscape plants, including shrubs and turf, remove smoke, dust, and other pollutants from the air. One study showed that I acre of trees has the ability to remove 13 tons of particles and gases annually. Landscaping lowers summer air temperatures. According to the EPA, urban forests reduce urban air temperatures significantly by shading heat sinks such as buildings and concrete, and returning humidity to the air through evaporative cooling. Trees shading homes can reduce attic temperatures as much as 40 degrees. Landscaping conserves natural resources Properly placed deciduous trees reduce house temperatures in the summer, allowing air conditioning units to run 2 to 4 percent more efficiently, but allow the sun to warm the house in the winter. Homes sheltered by evergreen windbreaks can reduce winter heat loss and are generally warmer than homes without such protection. By using trees to modify temperatures and protect against wind, the amount of fossil fuels used for cooling and heating is reduced. Landscaping screens busy streets. Well-placed plantings offer privacy and tranquility by screening out busy street noises and reducing glare from headlights.