Lawn maintenance produces a substantial volume of grass clippings, which many homeowners view as an inconvenient waste product. These organic remnants are a valuable resource rich in water and essential nutrients. Instead of disposing of them, clippings can be repurposed across the landscape to improve soil health, reduce maintenance, and save money on fertilizer. The choice of what to do with them depends on the volume collected and the specific needs of your garden or lawn.
The Easiest Solution: Grasscycling
The most straightforward method for managing clippings is grasscycling, which involves leaving the finely cut material directly on the lawn surface. Grass blades are 80 to 85% water, meaning they decompose rapidly, typically within two weeks, returning moisture and organic matter to the soil. This process is beneficial because clippings can supply up to 25% of a lawn’s annual nitrogen requirement, acting as a natural, slow-release fertilizer.
To grasscycle successfully, adhere to the “one-third rule,” ensuring no more than one-third of the grass blade height is removed during any single mowing session. This keeps the clippings short enough to filter down to the soil surface without forming clumps that could smother the turf below. Using a mulching mower is helpful, as it finely chops the clippings, ensuring they disappear quickly and effectively feed the lawn. Grasscycling improves soil structure and helps the turf stay green longer by retaining moisture.
Turning Clippings into Compost
If the volume of clippings is too large for grasscycling, they function excellently as a “green” material in a compost pile. Clippings are a strong source of nitrogen, which microorganisms use to build protein, giving them a low Carbon-to-Nitrogen (C:N) ratio, often ranging from 12:1 to 25:1. This nitrogen-rich content accelerates the decomposition of carbon-heavy “brown” materials like dried leaves, straw, or shredded paper.
The optimal C:N ratio for rapid, odor-free composting is approximately 30:1, meaning fresh clippings must be balanced with browns to prevent the pile from becoming too nitrogen-heavy. Adding too many fresh clippings at once is a common mistake; their high moisture and density can compress, excluding oxygen and creating anaerobic clumps. This anaerobic environment leads to a foul, rotten-egg smell because decomposition slows and noxious gases are released. To avoid this, mix fresh clippings thoroughly into the pile with a 2:1 ratio of browns to greens, ensuring good air circulation and preventing matting.
Using Clippings as Garden Mulch or Fertilizer
Grass clippings can be utilized directly in vegetable gardens and flower beds for specific benefits. As a garden mulch, a thin layer of dried clippings helps suppress weed growth by blocking sunlight from reaching the soil surface. This layer conserves soil moisture by reducing evaporation, which is helpful during dry periods.
When applying clippings as a mulch, keep the layer thin, ideally no more than one to two inches deep, to allow water and air to pass through easily. Thicker layers can mat together, creating a barrier that sheds water and begins to ferment, potentially generating unpleasant odors or harming plants. Clippings can also be steeped in water for a week or two to create a nutrient-rich liquid fertilizer, often called “grass clipping tea.” This nitrogen and potassium-infused liquid should be diluted before use and provides a quick nutrient boost for flowering and fruiting plants.
When Removal is Necessary
While repurposing clippings is generally the best approach, removal from the property is necessary in specific circumstances. The most significant concern is the presence of chemicals; if the lawn has recently been treated with herbicides or pesticides, the clippings should be bagged and disposed of according to local regulations. This avoids introducing these substances into garden soil or compost.
Another scenario is when the lawn is suffering from an active fungal disease, such as dollar spot or rust. Leaving the clippings on the lawn or adding them to compost risks spreading the fungal spores to healthy areas. Finally, if the grass is excessively overgrown due to heavy rain or a missed mowing, the volume of clippings may be too great to integrate safely. Excessively thick layers should be removed to prevent smothering the underlying turf, making municipal yard waste collection the necessary last resort.