Creating a Lush, Healthy Lawn without Synthetic Chemicals

Many people love their lawns. In the post–World War II period, they became a symbol of domestic status and beauty, and at the same time became more uniform and “greener.” And though it may seem odd to think about environmental damage and lawns at the same time, “chemical” lawns actually cause significant damage to the natural world, including the climate.

Besides being a costly choice from an environmental perspective, lawn care is surprisingly expensive for many consumers. The ongoing costs of regular applications of fertilizers and pesticides add up: the home renewal show, This Old House, estimates that the average U.S. lawn costs $100–$200 per month to maintain.

There are more lawns than any single food crop in the U.S. More than 20% of Massachusetts alone is covered in turf grass. Maintaining turf typically involves fossil fuel–based synthetic fertilizers, fossil fuel–based pesticides, fossil fuel–powered mowers, and large quantities of water. There is an alternative: we can choose to reduce or eliminate our dependence on fossil fuels for our lawns — and often, save money at the same time.

Consider how lawns impact the environment:

Fertilizers. American homeowners use about 3 million tons of nitrogen-based synthetic fertilizer on their lawns every year. These products contribute to climate change during the manufacturing process and as they are used on lawns. Most synthetic fertilizers have a high nitrogen content, which can cause a quick “green up” of a lawn, but does little for the health of the grass plants and their critical root systems. Furthermore, a lawn often does not need, and cannot utilize, the amount of nitrogen in synthetic fertilizers.

Nitrogen from fertilizers can run off into local bodies of water and penetrate into groundwater. In water bodies, this can cause eutrophication, in which algae blooms thrive (visible in water as green scum). This depletes oxygen in the water, and can lead to so-called “dead zones” and fish kills. EPA (the U.S. Environmental Protection Agency) estimates that 40–60% of fertilizer nitrogen ends up in surface and groundwater.

Pesticides (herbicides, insecticides, fungicides, et al.). EPA notes that lawn chemicals can be absorbed through the skin, swallowed, or inhaled. During and/or after application, lawn chemicals can drift and settle on laundry, toys, pools, furniture, window screens, or other outdoor surfaces and objects. The agency also asserts that pets are at risk; studies show that the rates of lymphoma in pets of pesticide users are significantly higher than those in pets of non-chemical users.

Lawn equipment. Most lawn care equipment — including mowers, leaf blowers, and trimmers — in the U.S. is gasoline powered, requiring about 800 million gallons of gasoline annually, with an estimated 17 million additional gallons spilled by users. EPA notes that, together, this equipment released 26.7 million tons of pollutants in 2011, the most recent year for which data are available. The agency has also found that gas-powered lawn mowers create 5% of total U.S. air pollution.

In addition, the roar of lawn equipment can annoy neighbors and harm the hearing of those nearby. A riding lawn mower, for example, produces noise at 90 decibels. The National Institutes of Health (NIH) states that prolonged or repeated exposure to noise above 80 decibels can cause hearing loss.

Water use. Here in Acton, where we depend on our own town wells for drinking water, protection of water resources is essential. The water tables were so low in Acton in the summer of 2022 that Category 3 drought conditions were declared; this meant that we could water our lawns only once a week and only during certain hours.

Warming trends due to climate change indicate that we can expect, in the coming years and decades, an unpredictable mix of lower levels of precipitation punctuated by stormy deluges, which are poorly utilized by most kinds of turf, including the compromised soil structure that results from years of synthetic chemical applications. Remarkably — and worryingly — much of the water consumed by Acton residents ends up on lawns.

Transitioning to a Healthy Lawn

Changing practices from conventional lawn management to those that create and maintain healthy, beautiful, and sustainable lawns is a gift to ourselves, our families, and our environment. This transition involves attention to several factors; however, the landowner does not need to address all of them at once. The transition to a healthy lawn takes place over the course of a few years as the mix of grass changes, and the structure and health of the soil and its microbial ecosystems improve — making lawns far more resilient. Bear these factors in mind as you begin transitioning to a healthy lawn.

Many homeowners use a landscaping service to maintain their yards. Ask your lawn services provider what products they are putting on your lawn and why. Your landscaper may not be familiar with the principles of transitioning to and maintaining a nontoxic, sustainable lawn. Ask if they are willing to support your desire for a healthier lawn in their practices. They should offer you a plan or, if necessary, you can tell them what you want to be used on your lawn. There are landscaping companies that provide sustainable lawn care services if your current company cannot do so.

A nontoxic, sustainable lawn depends on a healthy, biologically active soil environment, notes Chip Osborne, a specialist in sustainable lawns who educates and consults widely on the topic. The following points are based on his expertise. In making the transition to a healthy lawn, either you or your landscaping company will want to address these points:

Soil Health

Test your soil. When you test, you know exactly what you need to add to your soil to achieve the lawn you want. Each soil test determines pH (soil acidity), macronutrients (like nitrogen, phosphorus, and potassium, all of which are needed in larger quantities), and micronutrients (like zinc and iron, needed in smaller quantities). Soil testing is available from UMass; testing kits can be found at retail outlets or online.

Replace synthetic fertilizers with natural ones. Production of synthetic fertilizers consumes fossil fuels and releases greenhouse gases, and their use disrupts the soil ecosystem. By damaging the soil’s healthy microbial life, you are robbing the soil of its ability to replenish itself. Also, synthetic fertilizers have high nitrogen and salt content, which can leach into the surrounding water system. And, as Osborne notes, “pesticides do not always stay where they are put” — they can end up in many unintended places, including inside your home. Compost is the best all-round fertilizer for nearly all purposes, including lawns.

Adopt natural mulching practices. Use plant, animal, or mineral-based compost to top-dress your lawn; these can continuously feed the soil. You will find this approach more cost effective over time. Free compost may be picked up at Acton’s Transfer Station for those with a sticker. (Note: if you want to use only organic practices and products, be aware that compost from the Transfer Station may well have synthetic pesticide residues in it.) You may also use compost from your backyard composter, or purchase it in bag or bulk from garden centers.

Apply lime wisely. Because of our generally acidic soils, Acton residents need to apply lime, ideally in the Fall. Use 50 pounds per 1,000 square feet as a maximum rate in a single application. Note that lime can take 100 days to break down and effect a change in soil pH.

Evaluate whether you need to aerate the soil. Almost all lawns will benefit from aeration, and a great lawn demands it. That said, most lawns do not need it unless there is heavy foot traffic, excessive thatch, or heavy, clay-rich soils.

Thriving Grass

Plant more ecologically friendly grass. In most areas of Massachusetts, tall fescue is the most suitable because it is drought tolerant and resistant to disease and pests, and usually survives New England winters. For shady and less fertile areas, fine fescues (such as red fescue) are good choices. A blend of grass seeds makes your lawn more pest tolerant and disease resistant.

Avoid use of synthetic pesticides and herbicides. There are some plant protection products that are permitted by the National Organic Program’s National List of Allowed and Prohibited Substances for organic management. These are less likely to imperil pollinators, e.g. But it’s important to look at all product labels for warnings like “poison,” “toxic,” or “danger” and use these products only according to directions.

Water Conservation

Use water sparingly. Lawns need 1” of water (including rainfall) per week during May, June, and September; that increases to 2” weekly (including rainfall) in July and August.

Divert roof runoff to low-lying areas or rain barrels; use that water for lawns.

Mowing

Keep your grass taller. Set the mower blades to 3–4 inches to create a luxuriant green lawn. The longer the blades of grass, the deeper and more productive — and drought-resistant — will be the roots underneath.
Keep mower blades sharp for the whole mowing season. A dull blade rips and pulls at the grass blades, weakening them and promoting grass diseases.

Lawn Care Equipment

Use sustainable equipment for mowing, leaf-blowing, and trimming: switch from fossil-fuel driven equipment to manual or electric. In the last few years, the prices of electric equipment have dropped, and their quality has risen dramatically. In addition to lowering consumption of gas and oil, you will be kinder to the climate and to your ears — and those of your neighbors.

Resources

Lawn specialist Chip Osborne of Osborne Organics has done numerous talks and articles on sustainable lawn care:
• “Simple Steps” to Organic Lawn Care
• Organic Management of Natural Grass (video)
• Organic Lawn Care with Chip Osborne
Also, check out Lawns and Landscapes in Your Watershed, an article from the Commonwealth of Massachusetts.