How High to Keep Lawn Grass

Benefits of Higher Mowing

• When grass is allowed to grow taller, the height shades out the growth of weeds and helps hold in soil moisture. Short grass allows sunlight-loving weeds to grow and results in faster soil moisture evaporation. Mowing a lawn to the proper height allows the longer blades of grass to convert sugars into starch. These starches then feed the root system's growth. Deeper roots result when the grass isn't cut too short. A well-established root system makes the grass grow faster and greener and reduces the amount of water needed to maintain the grass.

How Much to Cut

• Never cut more than 1/3 of the plant's height at a time. If the grass is 3 inches tall, cut only 1 inch. The top 1-inch clipping can easily fall between the grass blades to replenish the soil with nutrients. By only cutting one-third of the plant, you leave two-thirds of the plant to continue growing and feeding the root system. This cutting method invigorates the plant to increase its root system. New rhizomes can grow to help produce a thicker, healthier lawn.

Cool-season Grasses and Warm-season Grasses

• Set your lawnmower's blade height between 2 1/2 to 3 1/2 inches for cool-season grasses and between 1 1/2 and 2 1/2 inches for warm-season grasses. This is done by adjusting the wheels on push mowers and by adjusting the mower deck on riding lawn mowers. Cut your lawn whenever it has grown 1 inch above these optimal heights.

Growing Seasons

• Mow your lawn every 5 days during the spring, summer and fall growing seasons. Adjust that plan according to how fast or how slow the grass is growing. When the grass has stopped growing in late fall or early winter, mow it once again to reduce the chances of winter matting.