The top quarter inch of the seedbed must be kept moist during the germination period. As the grass grows, decrease the frequency of the watering but increase the quantity of water for deeper penetration. Start mowing when the seedlings are high enough to cut, usually 2-3 inches. Mowing will enhance lateral growth and help reduce competition from weeds. Expect some weeds to crop up.
Weeds usually grow faster than good grass and typically come from weed seed in the soil.
With regular mowing many of the weeds will be eliminated. After a spring or early summer seeding, a weed control can be used the following September. For late summer or fall seedings, delay the weed control application until the following spring. Prepare the seedbed as you would for seeding. Buy sod that is three-quarters to an inch thick.