The sod, essentially a pre-grown lawn rolled out like a carpet, provides instant ground cover, but it is not instantly established. While the turf looks like a mature lawn, the roots have been severed from their original soil and must now grow into the new ground beneath. The answer to whether you have to mow sod is unequivocally yes, and the timing of this first cut is the single most important factor for the long-term success of your new lawn. Taking the proper steps ensures the delicate new roots can anchor themselves without being torn up by the mower.
Determining the Right Time to Mow
The decision to mow should be based exclusively on root establishment, not a fixed number of days after installation. The primary test for readiness is the “tug test,” which determines if the new roots have anchored into the native soil. To perform this, gently lift a corner of a sod piece; if it resists and stays firmly in place, it is likely rooted enough to handle the stress of mowing. If the piece lifts easily, you must wait longer, as mowing too early will cause the sod to shift and may tear the fragile, newly forming roots.
Allow the grass blades to reach a height of about 3.5 to 4 inches before attempting the initial cut. Waiting until the grass is sufficiently tall ensures that the subsequent cut still leaves enough leaf surface area for photosynthesis. Cutting the blades too short prematurely stresses the grass, diverting its energy away from root development and into leaf regrowth.
Preparing the Sod for the First Cut
Before mowing, check the ground conditions to prevent damage to the new turf. The soil must be firm enough to support your weight and the mower without sinking or leaving deep footprints. Mowing soft or muddy sod will cause ruts and can easily tear the unanchored sections of turf, disrupting the root structure.
It is also crucial that the grass blades themselves are completely dry before you begin to mow. Cutting wet grass can lead to an uneven cut and cause clippings to clump together, which can smother the new turf. Additionally, walk across the entire area to clear any debris left over from the installation process, such as small stones or loose scraps of sod. A clean path ensures the mower blades do not strike objects that could cause damage.
Executing the Initial Mow
The first cut on new sod requires a specific technique to minimize stress on the root system. You should set your mower to its highest possible setting, aiming to remove no more than one-third of the grass blade length. This “one-third rule” ensures the grass retains enough foliage to produce the energy needed for continued root growth.
Ensure your mower blades are extremely sharp before starting, as dull blades will tear the grass instead of cutting it cleanly. A jagged cut leaves the grass susceptible to disease and requires energy to heal, pulling resources away from root establishment. If possible, use a lightweight walk-behind mower for the first few cuts to reduce the pressure on the soft soil.
Move the mower slowly across the lawn, avoiding sharp turns that could cause the wheels to pivot and rip up the sod pieces. When you reach the end of a pass, lift the mower before turning to prevent scuffing the turf. If the clippings are light and sparse, you can leave them to decompose and return nutrients to the soil. If the clippings are thick and cover the grass in clumps, you must bag or rake them to prevent smothering the fragile grass blades. Once this first mow is complete, you can transition to a regular maintenance schedule, continuing to follow the one-third rule.