Are lawns really killing the environment?
Let’s face it— many Americans have a love affair with their lawns. Waking up early on a Saturday morning to mow a tidy swath of bright green grass, waving hello across a white picket fence to the neighbor who is busy doing the exact same thing, is basically a quintessential slice of the American Dream. But recently lawns have become a controversial topic, with people exclaiming you should “kill your lawn!” and “plant native!”. While the overall sentiment towards manicured lawns has been gradually changing over recent years, 40-50 million acres (roughly the size of Oklahoma, or all of New England) of the United States are still covered in turf grass. So… is that really as terrible as some environmentalists claim? There is a lot of intense shaming and fear-mongering surrounding this subject on the internet these days, so I am just going to lay out some information to help you decide for yourself. Let’s look at the pros and cons:
Benefits of mowed turf lawns:
A cushioned, durable space for kids and pets (and adults!) to play outside.
A tidy, uniform, suburban look that appeals to many. Provides contrast against flower beds, trees, and shrubs.
Complies with most HOA requirements.
Can be a relatively affordable groundcover to install per square foot.
Provides visibility near intersections and across landscapes, compared to most trees and shrubs.
Resistant to foot traffic near sidewalks and paths.
Sequesters more carbon than a paved, artificial, or bare soil surface (approx. 5.8 tons of carbon per hectare per year, although an average of 32% of that carbon is reintroduced through maintenance activities, not including irrigation).
Reduces stormwater runoff, limits erosion, and absorbs more noise compared to paved surfaces, gravel, bare soil, or artificial turf.
Ground temperature is significantly cooler than concrete (about 18 degrees cooler in this video).
Downsides to mowed turf lawns:
Vast majority are invasive or non-native monoculture species which do not provide any habitat or food sources for pollinators, birds, and other wildlife.
Little to no variation in color, texture, or height to provide visual interest.
One of the most labor-intensive and expensive groundcovers to maintain per square foot.
Do not provide any privacy, screening, or windbreak in the landscape. Do not dampen as much noise as most shrubs or trees.
Sequester a low amount of carbon compared to other plants (conservative estimates show that trees sequester approx. 11 tons of carbon per hectare, or about 2.8 times more than the net sequestration of a hectare of turfgrass after accounting for maintenance). Depending on maintenance practices in a given area, turfgrass may actually produce carbon emissions rather than sequester it.
Irrigation as well as chemicals such as fertilizers, herbicides, and pesticides are often used to maintain uniform appearance. These can be expensive and can potentially have harmful health and/or environmental effects.
Lawn mowers and other gas-powered equipment are generally very inefficient and produce harmful emissions for our health and environment (more than 30 million tons of CO2 emissions released by lawn equipment in the US in 2020 – more than the greenhouse gas emissions of the entire city of LA!). In addition, an estimated 17 million gallons of gas are spilled when refilling lawn equipment each year, spreading into our soil and water.
Mowers, weed whackers, and leaf blowers contribute significantly to urban noise pollution which can negatively impact the health and quality of life of humans as well as wildlife.
Very shallow roots (especially when grass is mowed short) which do not provide as much protection against stormwater runoff and erosion compared to other plants with deeper root systems.
Ground temperature is significantly hotter than when planted with taller groundcovers, shrubs, or trees (between 33 and 46 degrees cooler in the same video)
Why do we like our lawns so much anyway?
Let’s dig into some context surrounding how lawns became an American mainstay. Vast green, closely clipped lawns became popularized in Europe in the 1700s and 1800s as a status symbol, since only the wealthy had servants to hand scythe the grass, the ability to devote precious acreage on non-productive lawns (vs. food crops), and had ample leisure time to play yard games. This cultural ideal was adopted by American settlers, and exotic turf grasses were imported in order to create tidy European-inspired landscapes as well as to feed livestock. While the livestock enjoyed snacking on these monoculture eurasian grasses, the natural wide variety of habitats and food sources of our native wildlife was gradually destroyed. During the 20th century, with the rise of planned suburbs, golf and other organized sports, public parks, and homeowner’s associations, lawns soon became a hallmark of American success. If you think about it from the perspective of a landscaper or developer, rolling out a nice carpet of sod is one of the easiest, cheapest, fastest ways to cover a bare landscape around a house for curb appeal. It also presents an ongoing revenue opportunity, because now the homeowner will probably want to pay for products or services in order to maintain that nice lawn, including mowing, fertilizing, adding sprinklers, and spraying pesticides and herbicides.
European-style lawns are good for yard games, but they don’t provide much in terms of wildlife value.
If I can afford to maintain my lawn, what’s the problem?
Synthetic fertilizers are often used to keep our lawns thick and green, but after irrigation or rainfall they can create runoff into our groundwater and local waterways, leading to devastating consequences like toxic algae blooms, fish kills, and contaminated drinking water. The EPA estimates that landscape irrigation accounts for about a third of all residential water usage in the US. That means we collectively use a whopping 9 BILLION gallons every day, just to water our yards! In addition, we have lost around 90% of our native grasslands due to agriculture and development. Most of us are aware of the impacts of deforestation, but many people don’t realize that around 40% of land in the US was once native grasslands and open savannas. Many important species of plants and animals are now endangered or threatened due to this extreme habitat loss. Last, our gas-powered mowers, blowers, and weed whackers usually have inefficient two-stroke engines which all emit air pollutants and particulates, contributing to ground ozone (smog) and harmful exhaust emissions. These pollutants, which may cause respiratory problems, cardiovascular disease, neurological conditions, and cancer, pose an especially high risk to children, the elderly, and people with health conditions such as asthma.
Due to grassland habitat loss, native species such as quail could be on track for extinction by 2050.
Okay, so do I really need to kill my beautiful lawn?
The facts suggest that our environmental footprint, health, climate, and the wildlife around us would all likely be better off if we eliminated (or reduced the size of) our non-native turf lawns and planted native grasses, perennials, groundcovers, shrubs, or trees instead. Our neighborhoods would probably regulate temperature better, be less noisy, have better air quality, and attract more birds and beneficial insects (which tend to eat annoying things like garden slugs and mosquitoes!). Native plants and trees often require much less maintenance because they were perfectly designed by mother nature to thrive in your local ecosystem. They are better protected against pests and diseases and more likely to survive using only your natural soil nutrients and normal levels of rainfall, without the headache and cost of adding synthetic chemical fertilizers, fungicides, pesticides, or extra irrigation. Some native plants can sequester as much as 9 times more carbon than invasive species. Non-native edible plants might still need maintenance and irrigation, but they have the added benefit of feeding your family nutrient-dense produce, helping to build local resilient food systems, and reducing food miles. On the other hand, if you are deciding between a grass lawn and artificial turf or non-permeable paved surfaces, I would personally recommend the lawn. Compared to an artificial or paved surface, turfgrass decreases stormwater runoff, reduces temperature, improves air quality, and sequesters some carbon.
In short—compared to other types of landscape or garden plantings, lawns aren’t a great choice for benefitting your local wildlife and reducing your environmental impact. But if you love your grass (or your pets or kids do… or your HOA requires it), the good news is there are steps we can each take to reduce the impact on both our local ecosystems and the larger environment.
While most mowed turfgrasses have roots less than 6in deep, with optimal care practices including high mowing, infrequent watering, and maintaining loose, aerated soil, fescue roots can reach 3ft deep or even more. On the other hand, the roots of many perennials and native grasses can easily extend 6ft (some even 10 or 15 ft!), which helps prevent erosion and water runoff while capturing lots of carbon.
How can I make my lawn more sustainable?
Leave the leaves and/or grass clippings. Some estimates show that using a mulching mower to recycle clippings and let them decompose on the lawn can reduce the amount of carbon released into the atmosphere by as much as 59%. It also improves lawn and soil health by adding back in up to 30% of the lawn’s nitrogen needs, as well as other nutrients like phosphorus and potassium. It’s less work for you, and it keeps that nutrient-dense organic matter in your lawn and out of landfills. If the leaves or clippings are so dense that they might choke out or smother your yard, you can break up dense clumps with a rake or blower and add any excess to your garden beds or compost bins as free organic matter to help feed your soil.
Add in biodiversity with native plants. Plant a colorful mixed border of blooming perennials and shrubs around the outside edges of your grass lawn to attract wildlife, support pollinators, and benefit your local ecosystem. If you aren’t married to the idea of a perfectly uniform lawn, but just want a nice grassy area for your pets or kids to play, consider overseeding in some native wildflowers, nitrogen-fixing species, or low-maintenance groundcovers into your lawn. Or just stop applying herbicides and see what native / beneficial species might come up (and then pull or kill any noxious weeds). You might be surprised at how much more lush and resilient your lawn becomes when you stop forcing it to be one big non-native monoculture!
Mow a little higher, later, and/or a little less often. Mowing high encourages the roots to grow longer and stronger— which makes your grass less susceptible to weeds, more resistant to drought, better at erosion control, and more efficient at managing storm runoff. Never mow more than one third of your lawn’s total height at a time. Mowing late in the day may also reduce ground ozone (smog) pollution because the particulates react to sunlight. Mowing less frequently reduces emissions and noise pollution from maintenance equipment. On the other hand, waiting too long in between mowing (more than 3 weeks) can sometimes allow noxious weeds to go to seed and spread more easily.
Water less frequently. Instead of running your sprinkler every day or so, you can water a bit more deeply, but less frequently (maybe once a week or so), to make your lawn grow deeper roots which help with drought resistance. Make sure you are set up to skip watering if you have already received enough rain, obviously since this wastes water but also since it may contribute to excess nitrogen runoff. You could also consider just letting your grass turn a little brown during periods of drought or extreme heat. The kids and pets don’t care what color the grass is!
Fertilize strategically. Using natural amendments and organic fertilizers such as compost, bone meal, seaweed/fish products, and animal manures can replace synthetic fertilizer usage. These are naturally slow release, can help restore your soil’s microbial health, and can help bring back beneficial earthworms for natural aeration. Only fertilize when necessary (typically twice a year) to avoid runoff and waste.
Shrink your lawn. Even if you love your lawn, there are probably areas of it that aren’t really serving you. Those spots that are hardly ever used, too sunny, or too difficult to mow might be better suited for trees and shrubs, a vegetable garden, berry patch, or pollinator meadow. In deep shade, a fern or moss garden might be a nice change of pace. If the lawn is causing you more trouble than it’s worth in some areas, consider swapping it out! The benefit to your local wildlife and your environmental footprint are most certainly worth it!
In the end, we all could make better choices to reduce our environmental impact. We should probably all get rid of our cars, and only shop secondhand, and give up cheeseburgers. To spin off of Anne-Marie Bonneau’s quote about living zero waste: “We don’t need a handful of people [making every eco-conscious choice] perfectly. We need millions of people doing it imperfectly.” So if your lawn doesn’t bring you joy— absolutely, kill it. Consider sheet mulching with cardboard and then planting edibles or native plants that can help feed your family and local wildlife. If you need or want to have a lawn for whatever reason, consider shrinking it, adding native plants around it, or modifying your maintenance habits to be a little kinder to your health and environment. We can all do a little something to make this year greener than the last. Whatever you do, keep on growing!
