Science

Hide Your Weed Wacker! Lock Up Your Pesticides! It’s No Mow May.

Why more and more Americans are letting their lawns go wild each spring.

An overhead, slightly obscured view of a lawnmower rolling over a field of grass
Put that thing away! Daniel Watson/Unsplash

If you live on a decent-sized property in a major Middle American city or a grass-covered suburb in the Northeast, there’s a good chance your local government is encouraging you to keep your lawnmower locked up right now. It’s “No Mow May”—a month to reconsider what your lawn can really do for you and the broader environment, and a hot spring trend that has steadily bloomed over the last three years to lawn-rich communities across the United States.

More and more people are saying it, literally: Neglecting the mow is the way to go. In fact, while letting your lawn lie fallow, you can also cut back on all the other resources they demand of us: the staggering amounts of water, the smelly and harmful pesticides, the overpriced fertilizers from your local department store. Sure, it may not seem the most intuitive concept at first. Allowing the grass to grow unseasonably high, even for just a month, means unchecked weed growth, the odd mole or rabbit, and surely a side-eye from visitors who associate neatly trimmed lawns with civic orderliness. But there’s a good reason why No Mow May has become a thing. And why even if your town isn’t officially marking it, you should start.

First and foremost: Lawns are bad. Really bad. Like, to the point that there are countless reasons why the U.S. as a whole should stop fencing off tens of millions of acres exclusively for these patches: Their existence contributes heavily to the biodiversity crisis by displacing species of native plant and animal life that are better suited to a local geographic region’s earth and climate; turf grass is awful for soil’s quality, as well as its ability to sequester carbon and absorb rainfall; the gas-powered equipment that is (mostly) used to simply maintain these things unleashes overwhelming amounts of greenhouse gases, air pollutants, and particulate matter; the water sprinklers and hoses that slake the grass’s thirst are also some of the most wasteful gizmos in existence; the fertilizers and pesticides people dump on them release toxic chemicals and gases that harm the surrounding environs by poisoning groundwater and surface water, and also harm other plants. Lawns: Not great!

And yet the lawn is such a basic, intractable part of adult life that we can hardly grok these drawbacks. The American dream was sold with the image of a house with a flat yard; the midcentury expansion of suburbia transformed the lawn into an aspirational object. “Lawns have always been a status symbol,” explained Molly Jacobson, a pollinator ecologist at the SUNY College of Environmental Science and Forestry. “The way we treat our landscapes goes back to Victorian times—that separation between us and nature, that we’ve conquered the wilderness.”

From there, learning to mow became a rite of passage and source of freelance youth employment, while maintaining a square of clean-cut greenery became a marker of community pride (and often a legal requirement!). What did keeping a short, verdant patch of turf do for you? It showed that you had made it, that you were a respectable person with a respectable family, that you were more trustworthy and civilized than your weird next-door neighbor. (Dinkelberg!)

Now, however, lawns have become a frequent flashpoint in the growing public understanding of climate change. Bees, moths, birds, flies, beetles, and other common critters are dying off at a horrific pace because they’re deprived of plants that provide their sustenance, which are often cut down in favor of lawn grass that they can’t eat from. “One of the major things that has happened to pollinators is this profound loss of food. Bees and a lot of other pollinators are dependent entirely on flowers for their diet: pollen as their source of protein and fat, and nectar for carbohydrates,” said Megan Milbrath, an assistant professor at Michigan State University’s Department of Entomology. When these creatures die, so do local ecosystems and agricultural crops—and from there, humans starve.

Beyond the bugs, there are the droughts. The stark water shortages and heat waves that afflict large swaths of the West Coast and the Southwest, necessitating rations of water supply and other creative solutions, help to magnify how much water is wasted every year maintaining unnatural green spaces. “When golf courses and lawns are using so much water, that becomes a talking point for people who’ve experienced these problems with droughts,” said Jacobson. What’s more, lawns’ vulnerability to heavy rain and flooding and dependence on fossil-fuel-powered machines make their existence a damaging feedback loop: harming the earth to cultivate the lawn that harms the earth. As opposed to turf grass and its related weeds, “our native plants, which are adapted to drought, which are adapted to extreme weather events, they have the ability, with deep roots, to deal with deluges of water,” said Liz Anna Kozik, a University of Wisconsin–Madison Ph.D. student in environment and resources. Cathy Caldwell, a resident of the Virginia “ruburbs” who advocates for “No Mow April” in her area, told me she began thinking about reducing the amount of grass in her yard because “I’m terribly, terribly worried about climate change.”

It makes sense, then, that more cities and states have warmed to a concept like No Mow May in recent years, and are encouraging it for various reasons. Kicked off in 2019 by the British charity Plantlife as a way to help bring back flower populations that have been decimated in the United Kingdom, No Mow May was introduced stateside in 2020 by the City Council of Appleton, Wisconsin, whose successful implementation encouraged other Wisconsin cities to give it a try—and, from there, municipalities in Michigan, Iowa, Minnesota, New Jersey, and Maine have followed, in addition to individuals giving it a shot on their own.

Why May? Because it just makes sense. As spring turns to summer and pollinating insects emerge back into the open, you lawn might sprout some stray dandelions or weeds, or become a bit ungainly. But that’s not bad! The soil should generate more plant life that’s actually suitable for its local environment, while winged creatures get their chance to feed off the wilder foliage in your midst.

That’s why American cities are interested in No Mow May—to save the pollinators, and to enjoy the added benefits of reduced machine noise and pollution, conserved water supplies, and far more color and life on their lawns. Because to leave your lawn for No Mow May doesn’t mean it has to become some festering eyesore. “One of the common misconceptions when you talk about pollinator habitat is that it has to look messy, but that doesn’t have to be the case, said Milbrath. “White Dutch clover grows very, very short, so you can still use it for a functional lawn, and it would put food onto the landscape. You also could think about putting in some really impactful trees, like a basswood tree, or some sumac along an edge. That is something that could look formal and will put a lot of blossoms in.”

In fact, No Mow May’s proponents wish to emphasize, the catchy slogan isn’t strictly prescriptive, and it certainly isn’t an excuse to not do anything. “I’m totally into the reduced-mowing thing, but I want people to do more than that,” says Caldwell. “Those who are pushing it also want us to do more, like creating pollinator gardens where we used to have lawns,” which could be seeded with plants like milkweed.

Indeed, the branding can seem somewhat misleading. It’s not that forgoing mowing for a month alone will suddenly change your lawn for the better; rather, it’s more useful to think of it as an entry point to mowing your lawn less frequently over time. It’s important to remember that not all of the weeds and renegade plants that pop up on an unmowed lawn are inherently beneficial for pollinators and the soil—and there are different regions and different native plants that work better for different native species. “If we mainly focus on honeybees, we are not serving all the native pollinators that live on our continent,” said Kozik, including butterflies, hummingbirds, and even bats. Active stewardship is still required, she added, and is of the utmost importance when it comes to creating a more pollinator- and climate-friendly lawn: “You should spend this month gardening instead of just ignoring your lawn.”

Thankfully, it doesn’t have to be that hard, and you don’t have to be an expert to get started. Even beyond No Mow May, Americans have rethought the roles of their lawns in creative ways. There are the TikTok-famous clover lawns, which encourage the growth of clover plants that, compared with grass, are more resistant to heat, require less water and chemical spray, and cost a lot less to keep up. (They also don’t need much fertilizer, since they naturally soak up airborne nitrogen.) There’s “naturescaping,” aka replacing your grass patches with plant species that are native to your local region. There’s the option of moss mats, which add vibrancy to environments that can’t grow much else. And hey, if you’re attached to that old Kentucky bluegrass, you could at least think about going organic with your lawn care instead of drenching the space with chemicals, or going electric with your motorized tools.

There has, naturally, been a backlash: from homeowners’ associations who prefer their lawns to look a certain way, from critics who don’t want No Mow May to be perceived as a blanket solution to the pollinator crisis, from skeptics who doubt whether the trend has practical benefits, and point to the fact that a study on the practice’s efficacy was recently retracted. (There remain plenty of other studies that show the environmental benefits of such alternative lawn approaches.) Kozik thinks a better slogan would be “No Spray May,” targeting the effects of herbicides and pesticides while looking beyond the confines of the suburban lawn.

Yes, even some No Mow May proponents don’t think it will fix everything. “It’s a good conversation starter, but ultimately, you still have a lawn,” says Jacobson. “It’s way better to not have as much lawn, to have native plants in there, to combine that with not using pesticides and changing the way that we do landscaping.”

Milbrath agrees. “I don’t think anybody thinks that No Mow May is going to single-handedly solve the issue with pollinators. But it’s part of the picture, and bringing awareness to lawns is super important,” she told me. A lush new flower garden aflutter with happy birds? I can’t think of a better advertisement for the no-mow lifestyle.