Poor drainage creates persistent problems for many lawns, leading to waterlogged soil, thinning grass, and increased disease. Heavy clay or compacted soils often hold too much water, starving grassroots of oxygen.
One traditional method to address this issue involves amending the soil with a specific type of sand. Coarse, washed sand improves soil structure, facilitates water movement, and can help level the turf surface. Gardeners and greenkeepers frequently use sweet sand to achieve these results.
Consider the Material
Sweet sand is a washed, coarse sand with minimal silt or clay content. Its particles are larger and sharper than fine mason or beach sand. This texture prevents compaction, creating permanent pore spaces in the soil that allow air and water to pass through.
The “sweet” descriptor historically refers to its clean, neutral pH, free of salts or organic matter that could harm grass. Using the wrong type of sand, like unwashed or fine sand, can worsen drainage by cementing soil particles together.
Test Your Soil First
Before applying any amendment, diagnose your lawn’s specific condition. Simple tests show if drainage is the core issue. Dig a hole about one foot deep and fill it with water. If the water drains slower than one inch per hour, you have poor drainage.
Observe your lawn after rain; standing water for more than a few hours indicates a problem. A soil test from a local extension service can confirm soil composition and pH, guiding your amendment strategy.
Prepare the Lawn for Application
Proper preparation ensures the sand integrates effectively with the soil. Mow the grass very short to expose the soil surface. Then, aerate the lawn thoroughly using a core aerator.
It removes small plugs of soil, creating direct channels for the sand to enter the root zone. Remove the soil plugs and any excessive thatch from the surface. Aeration relieves compaction and is a vital step for the sand to work beyond the top layer.
Apply and Level the Sand
Spread dry sweet sand evenly across the aerated lawn. Use a stiff broom or the back of a landscape rake to push the sand into the aeration holes and distribute it across low spots. Aim for a thin layer, typically no more than ¼ to ½ inch deep.
The grass blades should remain visible after application. The goal is to fill the holes and depressions, not to smother the turf. For large lawns, a mechanical topdresser provides the most uniform coverage.