How long do you need to water new grass seed?

Newly planted grass seed should be watered a minimum of twice a day, depending on how hot and dry the area is. The top inch of soil should stay moist to prevent the seeds from drying out.

Continue watering twice daily, or more if conditions are extremely hot, until the new grass has grown enough to be mowed once or twice. After this point a normal lawn watering routine can commence. The new grass should not be mowed until the seedlings have grown at least three inches high if planted on bare ground. Mowing routines should be normal if old lawns have been reseeded.