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For years, Toni Genberg assumed a healthy garden was a healthy habitat. That鈥檚 how she approached the landscaping around her home in northern Virginia. On trips to the local gardening center, she would privilege aesthetics, buying whatever looked pretty, 鈥渨hich was typically ornamental or invasive plants,鈥� she says. Then, in 2014, Genberg attended a talk by Doug Tallamy, a professor of entomology at the University of Delaware. 鈥淚 learned I was actually starving our wildlife,鈥� she says.

The problem, Tallamy explained, is with the picky diets of plant-eating insects. Most of these bugs鈥攔oughly 90%鈥攅at and reproduce on only certain native plant species, specifically those with whom they share an evolutionary history. Without these carefully tuned adaptations of specific plants, insect populations suffer. And because bugs themselves are a key food source for birds, rodents, amphibians, and other critters, that dependence on natives鈥攁nd the consequences of not having them鈥攚orks its way up the food chain. Over time, landscapes that consist mainly of invasive or nonnative plants could become dead zones.

Croplands can be just as destructive, making up nearly 20% of all land in the United States. And that doesn鈥檛 even include the single largest irrigated crop in the country. Covering more than 40 million acres in the U.S., grass lawn consumes an area roughly the size of New England鈥攍and that, for the sake of habitat conservation, might as well be pavement.

Considering how little habitat and food these monocultures provide, and the incredible amount of resources they require, is there any wonder why the global insect populations ?

But there are solutions. One, at least in theory, is quite simple: Plant more native species. It鈥檚 a calling that has spoken to a growing number of park managers, home gardeners, and landscapers鈥攎any of whom trace a direct line of inspiration to Tallamy. His research has helped overturn decades of harmful horticultural practice, forcing us to rethink how we tend to both public and private spaces.

Savanna Syndrome

In lieu of monocrops, landscapes with a larger, more diverse biomass of native species help support pollinators, sequester carbon, capture runoff, and rebuild habitats. found habitats with two or three native tree species are on average 25% to 30% more productive than monocultures, meaning they contribute that much more food and energy to an ecosystem. Habitats with five native tree species were 50% more productive. Wildlife is drawn to lands teeming with native plants.

For individuals who鈥檇 like to live a more sustainable lifestyle, the simple message of planting more native species is both productive and rewarding鈥攁 refreshing contrast to that blame the collective problem of environmental collapse on individual shopping choices. Like anything else, real change has to happen at the macro level, especially when it comes to turfgrass鈥攁 crop with deep cultural, even evolutionary roots.

Sociobiologists refer to the preference humans have for vast swaths of low-cut grass as 鈥淪avanna Syndrome.鈥� Open grasslands allowed our primitive ancestors to keep an eye out for predators. So even today, on a deep level, we feel safer when we can see to the horizon.

Until the Industrial Age, the demands of agriculture kept lawns at bay. They were seen mostly as status symbols that said a person had enough money to brush off the territorial demands of farmland. The invention of the lawnmower democratized the lawn, and further embedded its pathological hold on our psyches.

But lawns require huge quantities of water and often chemical treatments to maintain them鈥攏ot to mention the emissions produced by two-cycle lawnmowers. According to the Environmental Protection Agency, running a lawnmower for one hour as driving a typical car 100 miles. This resource allocation becomes more and more difficult to justify as climate change continues to dry up once-productive habitats. As a monocrop, lawns displace landscapes that could benefit people, plants, animals, and insects. It鈥檚 time for us to reconsider lawns on a grand scale, several researchers have concluded.

Considering how entrenched lawns are in the American imagination, to uproot them will require some give-and-take. Advocates say we need a culture shift as well as policies that support it.

鈥淎s climate change and droughts worsen, we might get to a point where there鈥檚 political support to outlaw lawns,鈥� says Sarah B. Schindler, a professor of law at the University of Maine, who has written several papers about the legal authority of municipalities to ban lawns. 鈥淚 do think we鈥檙e seeing a change in norms, and I think part of that is tied to rising awareness of climate catastrophe.鈥�

Part of that work is simply raising awareness. Many people don鈥檛 think about the possibility of their yards as anything but turfgrass. As Tallamy puts it, lawn is the default landscape, but it doesn’t have to be. 鈥淧eople don鈥檛 realize there鈥檚 an alternative.鈥�

Choosing Native Plants

Some communities are beginning to impose alternatives. In , , and , where water shortages are a growing crisis, cities offer rebates for each square foot of lawn replaced with native or water-saving landscapes鈥攁 process known as 鈥渪eriscaping.鈥� In wetter climes, , and cities in , , , and have implemented rebate programs for the planting of rain gardens, which capture and infiltrate more runoff than grass. The city of , recently changed its municipal mowing to allow for the growth of meadows and glades in city parks. 

Throughout the country, local groups are advocating for the planting of natives on roadsides, medians, campuses, and parks. Some, like , encourage homeowners and neighborhoods to replace lawns with edible plants to establish food sovereignty and food security within their communities. Others take a more clandestine approach by planting 鈥済uerrilla gardens鈥� or tossing 鈥渟eed bombs鈥� into abandoned lots and properties where they don鈥檛 have the legal right to garden.

鈥淥ne thing that we鈥檝e learned with our research is that there is room for compromise,鈥� Tallamy says. Native planting doesn鈥檛 have to be all or none to make a difference. He gave the example of chickadee reproduction: If you have at least 70% native plant biomass in a given habitat, you can have sustainable chickadee reproduction. 鈥淭hat gives you 30% to plant perennials and exotics and other ornamental plants.鈥�

Tallamy鈥檚 research into the relationship between native plants and insects has inspired gardeners to do more than just turn their yards into native oases. Many are now creating resources to empower others to do the same.

The National Wildlife Federation created a , which allows users to plug in a ZIP code to find trees, shrubs, and plants native to their region. Following her horticultural revelation, Toni Genberg created , a resource to help users find, purchase, and learn about native plants. Since switching to natives, Genberg herself has seen all sorts of wildlife return to a property that, before, was only a suburban simulacrum.

Matt Bright is the conservation manager for the nonprofit charity Earth Sangha which aims to propagate and restore local native plant communities in the D.C. area. 鈥淲e鈥檝e set records for total plants distributed from our wild plant nursery for four years running,鈥� he says. 鈥淎nd overall, the trend has been towards more demand from all corners, whether that鈥檚 from park managers and ecologists, homeowners, or landscaping companies.鈥�

Biodiversity Among Buildings

But shifting away from lawns is complicated by the fact that municipalities have long adopted rules called 鈥渨eed ordinances,鈥� which require short ground cover for purely aesthetic reasons. This effectively mandates the planting and maintaining of lawns, as do many local zoning laws and HOA bylaws. And these rules aren鈥檛 always taken lightly. In Michigan a few years ago, a woman for growing a vegetable garden in her front yard instead of lawn.

People don鈥檛 want to be told that they can鈥檛 have their lawns, but they also don’t want to be told that they have to have a lawn.

The elephant in the room, of course, is property rights. Limits and requirements can inspire backlash. As Genberg points out, 鈥淎mericans don鈥檛 want to be told what to do, especially when it comes to their properties.鈥�

That鈥檚 why Tallamy has focused on talking to the public instead of advancing top-down regulation. Laws, especially bans, need public support to pass. To even think about regulating lawns you first need to change the culture around them. As people like Toni Genberg and Matt Bright show, Tallamy鈥檚 message is resonating.

鈥淲hat you do on your property affects everybody,鈥� Tallamy says. Nonnative or ornamental plants may not look like pollutants, but from an ecological standpoint, they are. Tallamy鈥檚 research bears this out: A new paper from his team shows just how effective nonnative plants are at destroying local habitats.

鈥淲e compared caterpillar communities in hedgerows that were invaded with non-natives versus hedgerows that were mostly native,鈥� he explains. 鈥淭here鈥檚 a 96% reduction in caterpillar biomass when they鈥檙e nonnative, so if you鈥檙e a bird and you鈥檙e trying to rear your young, you just lost 96% of your food.鈥�

But there鈥檚 a flip side, he says. If you take the invasive species out and put the native plants in, you鈥檝e just created 96% more food.

And this isn鈥檛 some gardening trend reserved for America鈥檚 suburbs and conservation lands. In Manhattan, the most densely populated urban center in the country, officials converted an abandoned railway line into a public park called the High Line, with a policy of planting at least 50% native species.

鈥淭here are monarch butterflies there, there are all kinds of native bees, which really surprised me,鈥� Tallamy says. 鈥淚f you can do that in Manhattan, you can do it anywhere.鈥�