Lawn sand is a specialized granular product designed to address two common issues in turf maintenance: moss infestation and dull grass color. This mixture serves as a multi-functional treatment, helping homeowners restore the health and appearance of their lawn. It works by delivering specific chemical compounds directly onto the lawn surface, where they interact with the moss and the grass plants.
What Ingredients Make Up Lawn Sand?
Lawn sand is typically formulated with three primary components. The bulk of the product is composed of very fine silica sand, which acts as an inert carrier for the active ingredients. The sand’s uniform texture allows for easy and even distribution across the lawn without smothering the grass blades.
The main active ingredient is ferrous sulfate (iron sulfate), which is responsible for the product’s moss-killing and greening effects. This mineral salt provides a concentrated source of iron. Many formulations also include a nitrogen source, such as ammonium sulfate, which functions as a fertilizer. This nitrogen encourages the grass to grow vigorously and fill in thin patches after the moss is removed.
The Dual Action: Killing Moss and Greening Grass
The power of lawn sand comes from the chemical reaction initiated by the ferrous sulfate upon contact with the moss. When the iron sulfate granules settle onto moss plants, the iron is absorbed, and oxidation occurs. This rapid chemical interaction causes the moss to essentially burn, leading to a visible blackening and death within a few days of application.
Ferrous sulfate also provides benefit to the grass itself. Iron is a micronutrient that plays a role in the grass plant’s ability to produce chlorophyll. Supplying the grass with readily available iron stimulates chlorophyll synthesis, resulting in a rapid deep greening effect. Additionally, the nitrogen component, if present, acts as a primary nutrient, promoting lateral growth and helping the turf recover quickly after the moss dies.
Step-by-Step Guide to Application
Successful application of lawn sand begins with proper preparation of the turf. Mow the lawn a few days before application, ensuring the grass is relatively short. The treatment should be applied when the moss is actively growing, typically during the spring or early summer, and on a calm, dry day to ensure even spread. Applying the product in windy conditions can lead to uneven coverage and potential drift.
Using a calibrated lawn spreader is recommended for the most uniform results, as it helps prevent over-application. The application rate will vary depending on the product’s iron concentration, but a typical rate is around 80 grams per square meter. If no rain is expected within 48 hours, the lawn must be lightly watered to wash the granules off the grass blades and into the soil. Approximately 7 to 14 days after the moss has turned completely black, it should be removed using a rake or a powered scarifier.
Necessary Precautions and Storage
The iron content in lawn sand requires careful handling, as it poses a risk of staining hard surfaces like concrete, paving stones, and decking. Granules spilled onto these areas must be immediately brushed or swept away without using water, as moisture activates the iron and causes permanent discoloration. Avoid tracking the product from the lawn onto walkways or into the house.
For safety, children and pets should be kept off the treated lawn until the product has been thoroughly watered in and the surface is completely dry. This prevents accidental ingestion and contact with the chemical components. Store the product in a sealed container in a cool, dry place. Exposure to moisture can cause the sand and active ingredients to clump together, making even application impossible.