Lawn leveling, often called topdressing, is a maintenance practice designed to smooth out minor surface irregularities, dips, and humps in a turf area. This process involves applying a thin layer of specialized material over the grass to gradually even out the grade. Using the correct mixture and application technique is necessary to ensure the turfgrass survives and continues to grow robustly through the newly applied layer. Proper material selection prevents suffocation and provides a stable, healthy environment for root development, which ultimately improves the playability and appearance of the lawn.
Selecting the Right Topdressing Material
The most suitable material for leveling a lawn is not just any sand but a specific grade known for its uniformity and drainage properties. Fine, washed, angular sand is the type most frequently recommended because its particles interlock, providing stability without compacting tightly. Angular grains improve the porosity of the underlying soil, allowing water and air to move freely, which is beneficial for root health.
Materials labeled as masonry sand or screened topdressing sand often meet these requirements, provided they are thoroughly washed to remove fine silts and clays. The ideal sand should have a uniform size, typically between 0.15 and 0.5 millimeters in diameter. Washing is important because it reduces the chance of the sand hardening into a cement-like layer that would impede water infiltration, ensuring the leveling layer drains effectively.
Using unsuitable materials can severely damage the turf. Beach sand often contains salts that can dehydrate and kill turfgrass. Play sand is too fine and tends to compact excessively, blocking air and water exchange. Builder’s sand can contain too much clay or silt, leading to poor drainage and soil stratification when layered over existing turf.
While pure sand offers excellent drainage and stability, many professionals prefer a custom topdressing mix for added benefit to soil structure and fertility. A common blend consists of 60% to 70% fine washed sand and 30% to 40% high-quality compost or topsoil. The organic component introduces beneficial microbes and holds nutrients and moisture, which pure sand lacks.
Applying a sand-compost mixture is particularly advantageous when leveling over heavy clay soils, as the organic matter slowly improves the structure of the native soil over time. This balanced approach ensures the turf is leveled effectively while simultaneously enriching the growing medium.
Essential Lawn Preparation Steps
Preparing the turf before applying the topdressing material ensures the new layer properly contacts the soil surface. The best time to undertake this work is during the turf’s active growing season, typically late spring to early summer or early fall. This timing allows the grass to quickly grow through the leveling layer; applying material during dormancy increases the risk of suffocation and disease.
The first step involves cutting the grass significantly lower than its normal mowing height. This low cut helps expose the soil and crown of the grass plant, preventing the leveling mix from resting on top of long blades. Immediately following the low mow, collect all clippings to prevent them from interfering with the material’s ability to settle.
Managing the thatch layer is another important consideration, especially in older lawns. Thatch is organic matter that accumulates between the soil surface and the grass blades. If the layer is thicker than half an inch, it should be addressed by dethatching or power raking to ensure the leveling material reaches the underlying soil.
Aerating the lawn before topdressing can significantly improve results, especially in areas with soil compaction. Core aeration pulls small plugs of soil, creating channels that allow air, water, and the topdressing mixture to penetrate the root zone more effectively. This process relieves compaction and encourages deeper root growth.
Techniques for Spreading and Leveling
Once the lawn is prepared, the application process requires careful attention to the quantity and distribution of the leveling material. Apply no more than a quarter-inch to a half-inch of material in a single application to avoid smothering the existing turfgrass. Applying too thick a layer prevents sunlight from reaching the grass crowns, which can lead to thinning or death.
The material should be transported using a wheelbarrow and dropped in small piles across the area needing correction. Use a shovel or the back of a rake to spread these piles into an even, thin layer over the designated sections. This initial spreading ensures uniform distribution before the final leveling takes place.
A specialized tool, such as a landscaping rake or a dedicated turf leveling rake, is then used to work the material down into the turf canopy. Drag the flat edge of the rake back and forth across the area, allowing the sand or mix to filter through the grass blades and settle into the low spots. The goal is to fill depressions while keeping the tips of the grass blades visible.
For larger areas, a drag mat or a simple push broom can be effective for smooth distribution. A drag mat, pulled across the surface, helps shear off high points and deposit material into surrounding lower areas. A stiff-bristled broom can also be used to brush the material off the grass blades and down to the soil level.
Addressing deep depressions, defined as those deeper than one inch, requires a gradual approach over multiple seasons. If a deep spot is filled all at once, the volume of material will likely suffocate the underlying grass. Instead, raise these areas by a half-inch per application, allowing the grass to grow through the new layer before the next application several weeks later.
Immediately following the leveling process, lightly water the turf to help settle the material and wash particles clinging to the grass blades down to the soil surface. This aids in consolidating the layer and encourages the grass to begin recovery. Continued proper irrigation and fertilization will promote rapid turf recovery.