MYTH BUSTING: Are Grass Clippings Clogging Our Landfills?

*The U.S. Environmental Protection Agency (USEPA) says at least one-third of all landfill material is yard waste and most of that is grass clippings.
*10-33% of the total waste stream in landfills is yard waste and grass clippings account for 2/3 of all yard waste.

1. “YARD TRIMMINGS,” ARE MORE THAN GRASS:

Based on a 1992 study, the USEPA estimates that “yard trimmings” including grass clippings, leaves, branches, brush and other plant materials, accounted for 17.9% of the total municipal solid waste, by percent of weight. Since 1960, when yard trimmings accounted for 22.8% of the total, this percentage has declined each decade, as follows: 1970 – 19.0%; 1980 – 18.2%; 1990 – 17.9%.

2. GRASS CLIPPINGS ARE WET & DEGRADE:

Most, if not all, studies of municipal solid waste are based on curb-side or landfill destination truck weights. Accordingly, 100 pounds of grass clippings weigh the same as a 100-pound refrigerator and they would be considered “equal” contributors to a landfill. However, grass clippings are 90% water and the remaining 10% is very degradable, unlike the refrigerator and many other landfill components such as plastics, metals, glass, construction debris, etc. If calculated at their dry weight, grass clippings would not be more than 2% of the total landfill volume and this volume will biodegrade very rapidly, helping to improve landfill soils and assist in degrading other organic matter.

3. “RESEARCH BIAS” CAN CONFOUND REPORTS:

A 1993 report on a study of Sacramento, California’s landfill composition reported that leaves and grass accounted for 26% of the total, leading second-place “non-recyclable paper,” at 8%, by a sizeable margin. However, one apparent purpose of the study was to identify potential income generating recyclable items and thus, different forms of paper were reported separately…non-recyclable paper, 8.0%; corrugated paper, 6.6%; mixed paper, 6.4%; newspaper, 6.3% and office paper, 1.0% for a “paper” total of 35.6%…well ahead of the 26% percent total assigned to “leaves and grass,” which we now know was calculated as a “wet” weight!

It should also be noted that the researchers made no apparent effort to distinguish high-water-content, rapidly decomposable grass clippings from tree leaves that most likely contain considerably less water and will take longer to decompose, depending on the variety of tree.

4. CLIPPINGS ARE TOO VALUABLE TO THROW AWAY:

Grass clippings contain an estimated 4% nitrogen that can be returned to the grass plant if they are allowed to remain on the lawn. Rather than disposing of clippings, they can be recycled in place to improve the turfgrass, save money and further reduce unfounded concerns about how they may contribute to landfill shortages.

1. Clippings are not a major landfill concern.
2. They’re too valuable to throw away.