Replacing a turf grass lawn with a mulched landscape is a practical decision many homeowners make to conserve resources and reduce yard maintenance. Traditional lawns require significant inputs of water, fertilizer, and time for regular mowing, especially in drier climates. Converting to a mulched area dramatically reduces water consumption by limiting evaporation from the soil surface and eliminating the need for constant irrigation. This transition also minimizes the long-term effort associated with routine lawn care, providing a sustainable alternative for managing an outdoor space.
Planning the Conversion and Selecting Materials
The first step in this project involves clearly defining the area’s boundaries and calculating the necessary material volume. Use a garden hose or landscape-safe spray paint to outline the exact shape of your new mulched bed, ensuring the lines are smooth and aesthetically pleasing. This visual boundary helps confirm the final layout and ensures you only remove the turf you intend to replace.
Determining the required amount of mulch is essential for efficiency and budget control. Mulch is typically sold by the cubic yard, which is equivalent to 27 cubic feet. To calculate the volume needed, multiply the area’s length by its width (in feet) to find the square footage, then multiply that figure by the desired depth (in feet). Finally, divide the total cubic feet by 27 to arrive at the number of cubic yards required. A standard application depth for new mulch is typically 3 inches, which equals 0.25 feet in the calculation.
Choosing the right material involves weighing the benefits of organic versus inorganic options. Organic mulches, such as wood chips or shredded bark, decompose over time, enriching the soil with nutrients and improving its structure. Because they break down, they require regular replenishment, usually annually. Inorganic mulches, like gravel or crushed stone, offer a permanent solution that does not decompose, but they do not contribute to soil health. Shredded bark and wood chips are often preferred for planting beds because they provide the benefits of moisture retention and temperature regulation while feeding the soil.
Methods for Eliminating Existing Turf
Successfully removing the dense, interconnected root structure of turf grass is the most demanding part of the conversion. There are three distinct methods to eliminate the existing lawn, each requiring a different investment of time and labor. The choice depends on the project timeline, the size of the area, and your preference for manual versus passive removal.
Physical Removal
Physical removal is the fastest method, involving the manual or mechanical slicing of the sod layer. Using a flat-bladed shovel or a rented sod cutter, set the blade to cut approximately 1 to 2 inches deep, just beneath the grass roots. The shallow cut minimizes the loss of underlying topsoil, which is important for the health of the new bed. The resulting strips of sod can be rolled up, shaken to remove excess soil, and then repurposed or composted.
Sheet Mulching
A less labor-intensive, yet slower, method is sheet mulching, which smothers the grass. Begin by mowing the area as low as possible and watering it thoroughly to encourage decomposition. Cover the entire surface with overlapping layers of unwaxed corrugated cardboard or 6 to 8 sheets of black-and-white newspaper. The cardboard or paper acts as a light barrier, stopping photosynthesis and causing the grass to die, while also serving as a weed barrier. This layer should be kept damp and then covered with a thin layer of compost followed by the final mulch, requiring a waiting period of 6 to 8 weeks for the grass to fully decompose.
Solarization
A third option is solarization, which uses intense solar heat to kill the turf. This method is best performed during the hottest months of summer. Start by watering the area well, as moist soil conducts heat more efficiently than dry soil. Cover the ground with a sheet of clear plastic, typically 2 to 4 mil thick. Ensure the edges are completely sealed by burying them in a small trench or weighing them down with soil or bricks. The clear plastic creates a greenhouse effect, raising the soil temperature high enough to kill the existing turf and many weed seeds within 4 to 6 weeks.
Applying the Mulch and Establishing Boundaries
Once the existing turf is eliminated, the final steps involve establishing permanent borders and applying the mulch layer. Installing edging creates a clean, defined separation between the mulched bed and any adjacent lawn or hardscape. Edging materials, such as plastic coils, metal strips, or stone pavers, should be installed with a slight lip (around half an inch) extending above the soil grade. This physically contains the mulch and prevents it from spilling onto walkways.
Before laying the mulch, gently rake the bare soil surface to loosen any compaction that may have occurred during turf removal. Avoid deep tilling, which can bring dormant weed seeds to the surface and cause new germination issues. The surface should be slightly graded to ensure proper drainage away from any structures.
The mulch should be applied evenly across the area, aiming for a consistent depth of 2 to 3 inches. This depth is sufficient to suppress weed growth by blocking sunlight and moderating soil temperature, while still allowing water to penetrate the soil below. Avoid piling mulch directly against the base of trees or shrubs, a practice known as creating a “mulch volcano.” Leave a clear ring of 2 to 3 inches of space around the trunk to prevent moisture buildup that can lead to rot and insect damage. The final step is to lightly water the newly applied mulch, which helps settle the material and prevents it from being displaced by wind.