Proper mowing practices are essential for the health of your lawn. Many homeowners and contractors make poor decisions when it comes to cutting practices. Many make the mistake of cutting the grass too low. Cutting grass too low allows sunlight to reach the ground which allows weed seeds to germinate. This can lead to a weed filled lawn requiring herbicide use. Cut your grass at a height of four inches. Taller grass helps to shade out weeds.
Washington DC area lawns can be ravaged by our hot summers. How many times have you seen contractors cutting nothing but dust on a hot August afternoon? Cutting frequency should decline during hot, dry weather. Conversely, grass grows faster during wet, cooler weather, therefore necessatating more frequent cutting. Cutting the lawn should be determined by the health and height of the grass. Never cut "just because it's Thursday".
Never bag your lawn clippings. Almost all mowers on the market today are available with mulching blades which grind up clippings into much smaller pieces than older models. Leave the clippings on the ground. Leaf blades contain nitrogen, an essential nutrient for plant growth. As they decompose, nutrients are released and become a valuable fertilizer for your lawn.
Have the blades sharpened every year. Grass leaves should be cut cleanly. A dull blade tends to rip the leaf. A ripped blade provides a larger opening for disease pathogens to enter the plant.
Vary your pattern every cut. This will help prevent "tracking" and soil compaction. Soil compaction can stress your lawn by reducing oxygen availability to grass roots.