Mow newly seeded bluegrass lawns at a height of 2 inches as soon as grass becomes 3 inches tall. Frequent mowing at this height will encourage spreading and promote a thicker lawn. If the new grass is allowed to reach a height of 4 inches or more, set the mower blade as high as possible and promptly mow. Gradually reduce the height of the grass in later mowings.
This article originally appeared in the May 6, 1992 issue, p. 71.