A Lush Lawn Without Pesticides

On one hand, it’s a minority of lawn owners who hire lawn-care companies or add fertilizers or pesticides to their lawns. In a February 2021 CR nationally representative survey of 1,772 lawn owners, 51 percent said they don’t use any pesticides or fertilizers on their lawns. And according to Peter Groffman, PhD, a professor at the Advanced Science Research Center at the City University of New York’s Graduate Center, who studies ecosystem ecology, “the biggest group of homeowners are what we call passive land managers—they just mow.”

Still, many American homeowners strive for a perfectly uniform, bright green lawn. And according to research by Paul Robbins, PhD, professor and dean at the Nelson Institute for Environmental Studies at the University of Wisconsin-Madison, many do this in spite of misgivings about the sometimes mysterious chemical inputs involved.

Lawn chemicals pose short- and long-term risks to health, and children are particularly vulnerable. Kids can accidentally ingest pesticides if they get their hands on them. Although acute poisonings are relatively rare, poison control centers still logged around 34,000 cases regarding pesticide exposure among children 5 and younger in 2019, according to the American Association of Poison Control Centers.

The long-term risks of chronic exposure to chemicals on our lawns are much harder to quantify than acute poisonings, but plenty of research has been conducted into how it may affect health. One thing we know: Lawn chemicals don’t just stay on the lawn. Research has demonstrated that pesticides can be tracked inside on shoes and clothes, where they then settle into the dust on floors and other surfaces. There, children, especially young ones who crawl around on the ground and explore the world by putting things in their mouths, are more likely to get these substances into their system.

The prenatal period and early childhood are also times when people are more vulnerable to the risks of these repeated tiny exposures, which may have long-term effects, says Sheela Sathyanarayana, MD, a pediatrician and an environmental epidemiologist at the University of Washington and the Seattle Children’s Research Institute.

Still, the specific health effects of cumulative exposure to individual pesticides are difficult to tease out, in part because pesticides are designed to be toxic to living organisms. Scientists don’t typically expose people to them on purpose to find out what happens, as they do with medications. The evidence we do have—based on observational studies and experiments in animals and in cells—is open to interpretation.

Take, for example, the herbicides 2,4-D and glyphosate (the active ingredient in Roundup). They were the two most common active ingredients found in home and garden pesticides used in 2012, the last year for which data on national pesticide usage was available from the Environmental Protection Agency. The International Agency for Research on Cancer, a part of the World Health Organization that investigates the causes of cancer in humans, classifies 2,4-D as a possible carcinogen and glyphosate as a probable carcinogen.

Still, the science isn’t perfectly clear. The IARC’s classifications of carcinogens only indicate the strength of the evidence showing a given substance’s link to cancer. But chemicals in the same category could pose very different levels of real-world risk. Bayer, glyphosate’s manufacturer, told CR that the IARC’s analyses of carcinogens “do not reflect real-world exposure,” meaning the agency doesn’t say whether the amount of a substance you would typically be exposed to is enough to be dangerous.

The EPA has ruled that there isn’t good enough evidence to say whether 2,4-D causes cancer in humans—and that glyphosate probably doesn’t. The EPA also says that although 2,4-D was indeed an ingredient in Agent Orange, it was a different component, known as dioxin, that was found to cause cancer. And Lindsay Thompson, executive director of the Industry Task Force II on 2,4-D Research Data, told CR that regulators have “consistently found 2,4-D not to have adverse human health impacts” when used as directed on the label.

A variety of studies, particularly among agricultural communities exposed to pesticides through their work or by proximity to farms, have linked these and other common lawn chemicals to an increased risk of other health problems, too. These include neurological issues, respiratory irritation, asthma, and liver and kidney damage. One 2015 study even suggests that both 2,4-D and glyphosate could be contributing to the development of antibiotic-resistant bacteria.

What’s more, several common lawn pesticides are suspected endocrine disrupters, meaning they might interfere with the body’s hormones. This is thought to occur at very low doses during certain vulnerable phases of life, such as the prenatal period and early childhood. Endocrine disruption may contribute to a range of issues, including diabetes and reproductive and developmental problems.

Still, industry groups maintain that the EPA’s approval of existing lawn pesticides means the chemicals should be safe to use as directed on the label. Responsible Industry for a Sound Environment, an association representing pesticide and fertilizer industry players, says the EPA reviews hundreds of studies to arrive at its approval of a pesticide. And Andrew Bray, vice president of government relations for the National Association of Landscape Professionals, says, “We look at EPA as the experts.”

It can be hard for consumers to know what to make of all this, especially when studies come to contrasting conclusions. After all, if these chemicals posed a real danger, why would they still be on store shelves?

In fact, David Dorman, PhD, a professor of toxicology at NC State College of Veterinary Medicine in Raleigh, N.C., says many dangerous products have been banned in the U.S., including DDT. Modern pesticides, he says, are “so much safer than what was used even 40, 50 years ago. So progress has been made.”

In theory, the EPA’s approach to regulating pesticides is precautionary—it requires manufacturers to demonstrate a chemical’s safety before bringing it to market. But many consumer advocates, including CR’s Hansen, say the EPA’s testing requirements are outdated and don’t reflect the latest in toxicological science. That allows some significant harms of pesticides to go undetected.

The problem, says Laura Vandenberg, PhD, associate professor of environmental health sciences at the University of Massachusetts Amherst, is that a clearer understanding of some of the most serious potential effects—such as cancer—may take decades to emerge. In that time, millions of people will have already been exposed unnecessarily, she says.

The EPA told CR that it is in the process of incorporating endocrine disruption into its standard tests for pesticide safety, and that it is implementing a set of new evaluation methods designed to reduce the need for animal testing. The agency says its risk assessment “ensures that when a pesticide is used according to the label, people and the environment are adequately protected.”

Lawn chemicals don’t just stay on your lawn or end up in your household dust. They can also sink deep into the soil, float off into the air, and be carried off by stormwater, ultimately causing harm to a range of organisms they were never meant to target.

A major component in conventional lawn care, fertilizer, is a key source of water pollution. The excess nutrients get washed out by rain into local waterways or sink into groundwater.

Once the nitrogen and phosphorus from fertilizer reach a lake or pond, they can prompt an overgrowth of algae, which eat up the oxygen in the water. That can cause fish to die en masse and sometimes makes water toxic.

Synthetic fertilizers and pesticides may also gradually degrade the health of your soil by diminishing beneficial microbes and fungi. Healthy soil, along with being great for your grass, can help keep carbon out of the atmosphere, an important bulwark against climate change, says soil scientist Asmeret Berhe, PhD, professor of soil biogeochemistry at the University of California, Merced.

If you’re concerned about the potential health and environmental effects of synthetic lawn chemicals, you might think the answer is choosing organic chemicals instead, or employing a green lawn-care service. But that can be harder than it sounds.

For agriculture, the federal government enforces regulations for food producers that would like to label their food as organic. But no federal laws exist for “organic” lawn-care products or service providers.

Before you hire a provider advertising organic lawn care, ask plenty of questions, says Michele Bakacs, associate professor and county agent with the Rutgers Cooperative Extension in New Jersey. “If the first thing the landscaper talks to you about is the type of product that they’re using, well, that may be a little bit of a warning sign,” she says. Instead, look for a provider that offers a soil test and talks to you about improving the health of your soil, putting the right plant in the right place for your yard and using several types of turfgrass. These are signs of a provider interested in the unique ecology of your yard.

Although uncertainty remains about the extent of the harms of lawn products, reducing risks to people and the environment is easy: Avoid using synthetic lawn chemicals. There are other ways to achieve the same goals that are better for your lawn and for your family (see “How to Rehab Your Yard”).

It can take a bit of a mindset shift, says Joseph R. Heckman, PhD, an extension specialist and professor of soil science at Rutgers University in New Brunswick, N.J. “If you want to have an organic lawn, you have to have a little bit of tolerance for something less than perfect,” he says. He underscores how important it is to create healthy and fertile soil as the foundation for an organic lawn.

Over the years, the practice of pesticide-free yard care has evolved for Lydia Chambers and her husband. They still live in New Jersey, and Chambers now considers herself an environmental activist. Their latest effort: converting much of their 3-acre property from lawn into meadow. Soon, in place of acres of trimmed turf, they’ll have a spread of native wildflowers and grasses. The meadow will encourage a more diverse ecology in her lawn, she says—and there’s a bonus: “It will be way easier than handling more flower beds.”