Sod is established grass held together by its root system, harvested with a thin layer of soil and transplanted to create an instant lawn. While the new turf provides immediate coverage, it is essentially a plant in shock, requiring time to heal and establish roots in the underlying soil. The initial weeks following installation are a delicate phase where the grass must dedicate its energy to integrating with the new ground. The first cut marks the transition from a fragile, transplanted piece to an established part of your landscape.
Determining Sod Readiness
The timing for the first cut is dictated by the extent of root growth beneath the surface, not a calendar date. Premature mowing can tear the sod from the soil, damaging the developing roots and setting back the establishment process. The turf must be firmly anchored to withstand the pressure and vibration of the mower.
To assess readiness, perform the “tug test.” Gently lift a corner or seam of the newly laid sod with your hand. If the turf resists your pull and stays firmly attached, the young roots have sufficiently penetrated the native soil. If the piece lifts easily, wait several more days before testing again.
The grass blades must also reach an appropriate height, generally three to four inches, before the first cut. Allowing the grass to grow tall ensures you avoid “scalping” the lawn. Depending on the climate and time of year, this rooting and growth period typically takes between 10 and 21 days after installation.
Proper First Cut Technique
The first mow requires careful preparation to prevent unnecessary stress on the young grass. Ensure the sod is completely dry before starting, usually by skipping watering the day before the cut. Mowing wet sod or soft, saturated soil can lead to the mower tires leaving ruts and displacing the unanchored turf.
Set your mower to its highest cutting height for the initial pass to remove the least amount of grass possible. Strictly adhere to the one-third rule: never remove more than one-third of the grass blade height in a single session. For example, if the grass is four inches tall, you should only cut it down to about 2.7 inches.
Using a sharp blade is important, as a dull edge will tear and fray the delicate new grass blades, leaving them vulnerable to disease and moisture loss. When operating the mower, make wide, gentle turns rather than sharp pivots. This minimizes lateral stress, preventing the newly rooted sod from being peeled or shifted.
Follow Up Care After the Initial Mow
Once the first cut is completed, transition your lawn care practices to encourage deeper root development. Before the first mow, frequent, shallow watering was necessary, but afterward, adjust to a less frequent but deeper watering schedule. This shift forces the roots to grow downward in search of moisture.
Water deeply a few times per week rather than daily, thoroughly soaking the top several inches of soil. This promotes a more resilient root system that can better withstand dry conditions. Establish a regular mowing schedule, maintaining the one-third rule and keeping the blade set high for the first several weeks.
If you did not apply a starter fertilizer before installation, the period immediately following the first cut is a safe time to do so. A light application of a low-nitrogen starter fertilizer provides the necessary nutrients, particularly phosphorus, to stimulate root establishment. Continue to limit heavy foot traffic on the new lawn for several weeks as the grass strengthens its connection to the soil.