You’ll never get to enjoy your lawn or mow your grass if you don’t correctly water it while it’s young. New lawns are like babies. They need lots of tender loving care. You need to keep pouring water on them to allow a strong root system to form. Watering correctly is just as important as giving them water. Keeping traffic off of the new lawn until the grass mature is vital to establishing a healthy stand of grass.
Grass roots need to form in two distinct directions. They need to be able to spread out and to go down deep. Light watering will work for the first type of roots, but you need to water for extended periods of time for the moisture to soften the soil so that deeper roots can form. A healthy yard needs roots that penetrate six or more inches deep. If you only water the lawn for 30 or 45 minutes in a given area, the water will probably not get beyond 2 inches deep. Continual repeated watering is needed for deep penetration. If you have a commercial water purification system, the process will be much easier.
On a new lawn, you need to water about 1 hour in each location and repeat this everyday that it doesn’t rain for the first two weeks that a new lawn is forming. The cumulative effect will be to have water sink below the root line of the lawn. If you go cheap here on water, your lawn will fade away in mid-summer and come back next spring with gaps and weeds. When this happens, you get into the tricky business of having to over seed and re-seed your lawn. Water is an investment in a permanent and beautiful lawn for years to come. Take caution if the weather is too cool for good germination of the seeds, and don’t over water so much as to cause erosion or washing the seed away.
As soon as the grass has reached about 3 to 4 inches in height, skip watering for about a day so that the soil will firm up enough for mowing. You will need to do this each week for a few weeks to give you lawn nice well-cut look. After you have mowed your new lawn two or three times, you can back off of the water to about one got shot per week. In exceptionally dry conditions, more watering may still be needed. If you get an inch or more of rain that week, you may not have to water depending on your specific climate. With sod, your watering needs will be similar because deep watering is still needed to allow the roots to penetrate the soil beneath the sod. After two weeks or so, sod can be used in the same way as a mature lawn.