Converting a lawn into a productive garden space requires the complete removal of existing grass, which is a highly competitive plant. Failing to eliminate the grass fully, especially perennial varieties, can lead to a persistent battle for nutrients and water against new plantings. The best approach depends on the area’s size, planting urgency, and whether you prefer a physical, organic, or chemical solution. Each method effectively kills the grass but varies in labor intensity, time commitment, and impact on the soil.
Manual and Physical Removal Methods
The quickest way to clear a plot of grass is through manual and physical removal, though this requires the most immediate labor. The simplest method involves using a flat-bladed shovel to slice underneath the turf, cutting the sod into manageable strips or squares. Aim to cut just deep enough to sever the roots, typically about two inches deep, and then roll the sections up like a carpet.
For larger areas, a motorized sod cutter, which can be rented from equipment suppliers, significantly speeds up the process. This machine uses an oscillating blade to cut the turf cleanly at a set depth, creating long, uniform strips that are easily removed. Physical removal is demanding, especially since the removed sod needs to be relocated for composting or disposal. With tenacious grasses like Bermuda grass or Quackgrass, ensure that all rhizomes are completely dug out, as even small fragments can regrow.
Smothering Techniques Using Organic Materials
A non-chemical method requiring minimal labor but a longer timeline is smothering the grass, depriving it of light. This approach, often called sheet mulching or lasagna gardening, simultaneously kills the lawn and improves the soil structure beneath. The process begins by mowing the grass short and thoroughly wetting the area to encourage decomposition.
Sheet Mulching
A thick layer of light-blocking material, such as overlapping corrugated cardboard or several layers of newspaper, is laid directly over the wet grass. It is essential to overlap the edges to prevent light from reaching the underlying lawn. This barrier is then covered with several inches of organic matter, such as compost, straw, or wood chips. The decomposition process takes several weeks to months, but the resulting soil is ready for planting directly into the top layer of added material.
Solarization
A related technique is solarization, which uses heat instead of light deprivation to kill the grass and weed seeds. This method involves covering the area with a sheet of clear plastic during the hottest months. The clear plastic traps solar energy, raising the soil temperature high enough (often above 140 degrees Fahrenheit) to be lethal to most vegetation and pathogens in the top six to twelve inches of soil. For solarization to be effective, the soil must be moistened beforehand to improve heat conduction, and the plastic edges must be securely buried to trap the heat, typically requiring four to eight weeks of continuous sunlight.
Chemical Application for Complete Removal
When speed and complete eradication of tough perennial grasses are primary concerns, a targeted chemical application may be used. Non-selective systemic herbicides, such as those containing glyphosate, are absorbed through the leaves and travel down to the root system, killing the entire plant. This method is most effective when the grass is actively growing, providing ample leaf surface area for absorption and translocation.
Safety during application is paramount, requiring personal protective equipment (PPE) like gloves, long sleeves, and safety glasses. Apply the herbicide on a calm, non-windy day to avoid drift onto desirable plants nearby. A waiting period is necessary before planting to allow the herbicide to break down in the soil; most product labels recommend waiting at least seven days before introducing seeds or transplants.
Preparing the Plot for Planting
Once the grass is dead or physically removed, the plot is ready for the final preparation steps to support a healthy garden. Begin by clearing away any remaining debris, such as dead grass clippings, cardboard remnants, or the plastic sheeting used for smothering techniques. If sheet mulching was not used, the soil structure may be highly compacted, requiring loosening.
Soil testing is valuable at this stage to determine the existing pH level and nutrient composition, which guides necessary amendments. Lightly tilling or turning the soil, typically six to twelve inches deep, helps to aerate the ground and break up compaction. Introducing generous amounts of compost and other organic matter, such as aged manure or leaf mold, is crucial for improving soil fertility, water retention, and overall structure before planting begins.