Should I Mow Grass Before Fertilizing?

Lawns that are mowed and fertilized on a regular basis grow vigorously and cover the yard in a thick blanket of green, while lawns that are not cared for tend to become thin, weed-infested blots on the landscape. Though there are no hard, fast rules to lawn care, as a general rule, the grass should be mowed first, then fertilized; this removes excess lawn waste and exposes the soil, which helps the fertilizer work more efficiently.

During phases of active growth, lawns need plenty of nitrogen. These periods of development vary from one type of grass to another; cool-season grasses multiply rapidly during the early spring and autumn, while warm-season grasses are most active during the summer. Nitrogen is water-soluble, and while it is normally present in the soil, it does tend to be in short supply, as it is easily leached by irrigation and rainfall. Grasses also need potassium and phosphorous, but these nutrients are usually supplied by the surrounding soil.

To give the lawn a quick boost, apply an inorganic fertilizer that uses ammonium sulfate, urea or ammonium nitrate, as these water-soluble forms of nitrogen are easily taken up by plant roots. For slow, even lawn growth, choose an organic fertilizer or one that uses water-insoluble forms of nitrogen, such as urea-formaldehyde or sulfur-coated urea. These fertilizers break down slowly, providing the lawn with an ongoing supply of vital nutrients.

Mow the lawn to a height of 1 to 1 ? inches, then use a rake to remove the clippings and debris. Apply the fertilizer according to the package directions. If no directions are available use approximately 1 lb. of actual nitrogen for every 1,000 square feet of lawn. Do not mow the lawn again until the fertilizer has been properly watered in, either through artificial irrigation or natural rainfall, and do not reapply the fertilizer for at least six weeks.

When the lawn turns brown in response dry summer weather, do not worry. Many grasses naturally go dormant during periods of drought. They will green up when the rain arrives. Do not mow the grass until it turns green again; leaving the grass intact will help protect the roots from the scorching effects of the summer sun. Additionally, do not add extra fertilizer in an attempt to turn the grass green. Too much fertilizer can chemically burn the lawn, which only makes it look worse.