Low spots in a lawn are more than a cosmetic issue. These uneven areas cause water to pool, leading to poor drainage and potentially drowning grass roots. They also create a tripping hazard and result in an inconsistent cut when mowing. Repairing these imperfections is a manageable task for homeowners.
Identifying the Causes and Necessary Materials
Low spots frequently develop due to the natural settling of soil, especially after utility work or improperly filled trenches. Decomposition of buried organic material, such as old tree roots, can also create voids that collapse. Soil compaction from heavy traffic is another common cause, reducing air pockets and leading to a sunken surface.
The composition of the leveling material is significant for a successful repair. Using pure topsoil or sand alone is not recommended, as topsoil compacts and sand inhibits nutrient absorption. A high-quality leveling mix usually consists of a blend, such as 50% topsoil and 50% fine sand, or a mix incorporating compost. Experts recommend a final blend of around 70% sand and 30% organic material or loam to ensure proper drainage and growth.
Repairing Shallow Low Spots with Topdressing
For depressions less than 2 inches deep, the existing turf can be leveled using topdressing. First, mow the area shorter than usual and remove all grass clippings. This allows the leveling mix to make direct contact with the soil surface and ensures the grass blades are exposed.
The leveling mixture must be applied in thin layers, maximum 1/2 inch at a time, to prevent smothering the grass. Spread the material using a shovel, then use a leveling board or the back of a rake for even distribution. Work the mixture down into the grass canopy using a stiff brush or rake, keeping the grass tips visible. If the depression remains, wait for the grass to grow through the first application before applying another thin layer.
Addressing Deep Depressions Requiring Turf Removal
Low spots deeper than 2 inches require turf removal, as topdressing would suffocate the grass crowns. The existing turf must be temporarily removed to allow for the bulk addition of leveling material. Begin by using a straight edge, such as a 2×4 board, to identify the boundaries of the low area.
Use a flat-bladed shovel or sod cutter to slice around the perimeter and cut the turf layer, aiming for one to two inches deep. Gently peel back the sod, exposing the underlying soil. Add the leveling mix to the depression in layers, lightly compacting the material to prevent future settling.
After filling, use the leveling board to ensure the new soil surface is slightly lower than the surrounding grade to accommodate the sod thickness. Carefully replace the turf piece, then walk or gently tamp the sod to ensure firm contact with the new leveling material. The goal is for the replaced sod to sit perfectly flush with the adjacent lawn.
Watering and Post-Repair Maintenance
The final steps involve proper care to ensure the grass recovers quickly and the new soil settles correctly. Immediately after the repair, thoroughly water the area to help settle the leveling mix and hydrate the grass or replaced sod. This initial watering is crucial for establishing necessary soil-to-root contact.
For the following seven to ten days, keep the repaired area consistently moist but not saturated. This encourages the grass to grow rapidly or allows the replaced sod to root into the fill material. Gradually reduce watering after this period to encourage deep root growth, allowing the soil to dry slightly between cycles. Avoid heavy foot traffic or mowing for at least two to four weeks, or until the grass has firmly rooted.