Mowing the Lawn After Seeding

When to Mow

• Mow when the grass is about one-third taller than the intended grass height of the lawn. For example, if the lawn will ultimately be kept about 3 inches tall, cut it when the grass is about 4 inches tall. Monitor the grass as it grows after seeding. It may be necessary to mow the lawn in sections to accommodate areas where the grass grows more rapidly or slowly than in other areas.

How Much to Cut

• Cut one-third of the grass height when mowing. This leaves enough of the grass plant in place to continue photosynthesis and growth. Do not cut the new lawn too short. This allows more sunlight to reach the ground level between the plants which could lead to weed seed germination and growth.

Equipment

• Sharpen the lawn mower blade before cutting the new lawn for the first time. A dull blade pulls at the grass, which can displace the plants' new root structure. Avoid using heavy lawn mowers, such as riding mowers, on new lawns if the ground is soft. Allow more of the root structure to form to firm up the ground.

When Not to Mow

• Do not mow lawns, especially new lawns, when temperatures are above 90 degrees. The combination of heat and mowing stresses new grass. Always avoid mowing the lawn if the grass is wet because it makes the clippings clump and can damage the mower.