Removing an existing lawn is the first step for successful sod installation. Failing to clear the old turf creates a barrier between the new sod’s roots and the soil, preventing proper establishment and access to moisture and nutrients. Old grass and weeds also compete directly with the new sod for resources, leading to weak growth and an uneven surface. A clean slate ensures the new turf can root deeply, providing the foundation for a smooth, healthy, and long-lasting lawn.
Non-Chemical and Time-Intensive Methods
Homeowners who prefer to avoid machinery or chemical products can use methods that rely on time and environmental conditions to eliminate the existing grass. One popular technique is solarization, which uses the sun’s heat to kill vegetation. This involves mowing the area short, watering it, and then securely covering the entire space with clear plastic sheeting, typically 2 to 4 millimeters thick, for four to six weeks during the warmest part of the year.
The clear plastic traps solar radiation, raising the soil temperature to levels between 104 and 140 degrees Fahrenheit, killing the grass, weeds, and seeds down to a depth of several inches. This process is most effective in areas receiving at least six hours of direct sun daily. An alternative is smothering, or sheet mulching, which involves covering the grass with overlapping layers of cardboard or newspaper before topping it with mulch.
Smothering works by completely blocking sunlight, starving the grass. This process is slower than solarization, often requiring several months to fully kill the turf and allow the organic materials to begin decomposing. For small areas, manual removal using a flat-edged shovel or spade is an option, although it is labor-intensive and challenging to ensure all roots are removed. When digging manually, water the area a day or two beforehand to soften the soil, making it easier to cut and lift the turf in manageable sections.
Quick Removal Methods
For larger areas or when time is limited, mechanical and chemical removal methods offer faster results. The most efficient physical method is using a powered sod cutter, which can be rented from equipment suppliers and quickly strips the turf in consistent, uniform rolls. A sod cutter works by slicing the grass and a thin layer of soil beneath it, typically set to a depth of 1 to 2 inches, which is sufficient to remove the root system.
Before operating the machine, the lawn should be mowed at its lowest setting and lightly watered to ensure the soil is moist but not muddy. The machine is guided in long, straight passes, and the resulting strips of old sod must be immediately rolled up and removed from the area to prevent the cutter from bogging down on subsequent passes. This mechanical process removes the unwanted grass.
A chemical approach involves applying a non-selective systemic herbicide, such as a product containing glyphosate, which kills all treated vegetation down to the roots. This option is highly effective, especially where aggressive weeds or perennial grasses are present, and requires minimal physical labor. Herbicide application must occur when the grass is actively growing. Wait seven to ten days after the final application to ensure the vegetation is completely dead and the chemical has degraded before installing new sod.
Final Soil Preparation for Sod Installation
Once the old turf is removed, creating a proper soil foundation is paramount to the new lawn’s success. The soil should be tilled to a depth of at least 2 to 3 inches to break up compaction and promote healthy root penetration. Tilling also allows for the incorporation of soil amendments, determined by a soil test to identify nutrient deficiencies or pH imbalances.
Adding organic material, such as compost, into the top 4 to 6 inches of soil improves both drainage in clay soils and water retention in sandy soils. This step is important for establishing a nutrient-rich and porous base. After amending and tilling, the area must be graded to create a smooth, level surface with a slight slope away from any structures to ensure positive drainage.
The final grade should be approximately three-quarters of an inch below the level of sidewalks, patios, or driveways. Using a landscape rake or a roller to firm the soil lightly helps reveal any low spots that need to be filled before the sod arrives. This ensures the roots make immediate and complete contact with the prepared soil.