The Hempstead Plains Preserve is a place where you can imagine the presence of creatures past. Birdfoot violets, now gone, once colored the landscape with a wash of purple in spring. The heath hen, a large grouse that went extinct 90 years ago, performed its elaborate courtship dances on the Plains.
On a late afternoon in October, the slanting autumn sun lit up in a blaze of gold the grasses and wildflowers on this narrow, 19-acre sliver of land — almost all that is left of the tallgrass prairie that once covered more than 50 square miles at the heart of Long Island, New York, a fish-shaped island that stretches east into the Atlantic Ocean. “This place wants to be a grassland so bad, but so many obstacles are in the way,” says Rob Longiaru, the preserve’s habitat director.
In 1741 an English physician traveling in the Hempstead Plains lost his way on trails that meandered through the towering wild grasses and was forced to “blunder about a great while.” A century later, when the poet Walt Whitman explored the grassland as a boy, it was a vast grazing commons. “I have often been out on the edges of these plains toward sundown,” Whitman wrote, “and can yet recall in fancy the interminable cow processions, and hear the music of the tin or copper bells clanking far or near and breathe the cool of the sweet and slightly aromatic evening air.”
Conservation gardens may seem small and inconsequential, but added together they can have a major ecological impact.
However, even the tenacious grasses that grew as tall as a horse’s shoulder proved no match for the demographic revolution that began in this globally rare natural community on the doorstep of New York City — urban sprawl. When World War II ended, real estate developer William J. Levitt constructed Levittown, an instant suburb of more than 17,000 modest, single-family homes for returning GIs. The development spawned copycat communities, creating the template for urban sprawl in the United States, and beyond.
The most striking thing about the remaining rectangle of grassland is the sheer improbability of its presence in the commercial core of suburban Nassau County, hemmed in by the Nassau Coliseum sports arena, a Marriott Hotel, Nassau Community College, a police academy, warehouses, and several multi-lane highways. Not only has the Plains shrunk drastically, but invasive plants from around the globe have taken root and pose a major threat to the native grassland denizens.
Many unique and disappearing landscapes like the Hempstead Plains endure only because dogged advocates struggle to raise funds to restore and maintain them. Now, a growing body of research is demonstrating that “conservation gardens” — planted in places like commercial zones, residential yards, schoolyards, and corporate landscapes — can help bolster these hotspots of urban biodiversity. The authors of a paper published in Landscape and Urban Planning last June sum up the new research: “While urbanization is a major contributor to declines in native biodiversity worldwide, ecological research across the Global North and South has demonstrated that yards can provide crucial habitats for birds, pollinators, and other wildlife within urban regions.”
Residential yards make up about 50 percent of the total green space in U.S. and western European cities. “That’s a significant amount of land with potential to provide quality wildlife habitat,” says Susannah Lerman, a U.S. Forest Service ecologist. In fact, these areas may seem small and inconsequential, but added together they can have a major ecological impact.
Lerman was one of the lead researchers of an ambitious five-year study, funded by the National Science Foundation (NSF) and published last year in Ecological Applications, which concluded that conservation gardening, when adopted on a wider scale, can help boost biodiversity. Lerman and her coauthors posited that when located adjacent to urban wildland fragments, these yards, planted with a variety of species and designed to attract wildlife, can help support resident flora and fauna by increasing the size of the available habitat and its connectivity to other natural areas. With the world urbanizing rapidly, she says, understanding how to conserve biodiversity in such human-dominated landscapes “is one of the century’s greatest challenges.”
When Betsy Gulotta arrived at Nassau Community College as a young biology professor in 1969, large swathes of the surrounding Hempstead Plains were still intact. While out exploring, Gulotta and her students would encounter nests of the upland sandpiper, a black, brown, and white-mottled grassland specialist known as the shorebird of the prairie. But in the early 1970s, she says, “when they started building the Coliseum and the Marriott Hotel and Charles Lindbergh Boulevard,” an eight-lane gash through the grassy Plains near where Lindbergh took off on the first solo transatlantic flight in 1927, “those birds just disappeared.” The same fate befell the grasshopper sparrows, box turtles, and countless other creatures that made their home in the ancient landscape.
A 2018 appraisal of the remaining Hempstead Plains ecosystem found 14 rare and vulnerable plants.
In 2001, with the wild grassland teetering on the brink of extinction, Gulotta and a group of colleagues formed Friends of Hempstead Plains. They persuaded the Nassau County executive, who by happy coincidence was Gulotta’s husband, to include two parcels in the county’s “perpetual preservation plan”: a 19-acre fragment on the Nassau Community College campus that is now the Hempstead Plains Preserve, and a more overgrown 26-acre, county-owned tract nearby, named the Francis T. Purcell Preserve. Today, the Friends manage both places. “Our dream,” says Gulotta, “was if we could preserve the college’s land and do what we could with the Purcell Preserve, maybe that’s enough to allow some of the wildlife to return.”
Like an increasing number of urban wildland fragments, the two preserves are a refuge for vanishing regional biodiversity. They harbor species unique to rare sandplain grasslands found only along the northeast coast of North America, including the state-threatened bushy rock rose, a low-growing perennial with large buttery yellow, five-petaled flowers. “The diversity that is still maintained in the Hempstead Plains is incredible,” says Polly Weigand, executive director of the Long Island Native Plant Initiative, an all-volunteer effort to protect the island’s botanical diversity by establishing commercial sources of local “ecotypic” plants — genetically distinct geographic varieties — for use in habitat restoration and by nurseries, landscape designers, and home gardeners.
A 2018 appraisal of the remaining Plains ecosystem by the New York State Natural Heritage Service found 14 rare and vulnerable plants. Alarmingly, the botanists also documented 34 invasive non-native plants that threaten Plains natives, up from six in the 1980s.
Although the Friends have been successful at protecting imperiled plants and removing opportunistic woody shrubs, controlling mugwort, cypress spurge, and other herbaceous invasives has been a critical challenge. Longiaru, a conservation biologist with the Town of Hempstead who moonlights as the Friends’ habitat director, mows and hand cuts regularly to keep down the problematic plants. Boy Scouts and other volunteers help. Gulotta, the group’s conservation project manager for 18 years, hopes there is enough money left from a BAND Foundation grant to burn a portion of the preserve next year to suppress woody vegetation and stimulate the native wildflowers and grasses. “We don’t have a lot of money,” she says. “We do what we can.”
Anthony Marinello, who grew up in West Hempstead in the early 2000s, discovered the Hempstead Plains as a biology student at Nassau Community College. “I stumbled upon the preserve one day when I was bored between classes,” he says. The grassland piqued his interest, and two years ago Marinello established Dropseed Native Landscapes, a nursery and landscape design business. Every Saturday from April through November he can be found at the farmer’s market at Crossroads Farm on Hempstead Avenue. Surrounded by his potted milkweeds, pussytoes, switchgrass, and other inhabitants of the grassland community, he encourages the locals “to plant their own little pocket of the Plains.” According to Marinello, “Most people around here are completely unaware that it even existed.”
“There are hundreds of papers now that look at the conservation role that residential yards can play,” says a researcher.
Conservation gardens, like those that Marinello plants for schools and individuals, are starting to appear in countries around the globe. Although still far outnumbered by manicured lawns, in the U.S. there are now more than a million pollinator gardens, over 40,000 registered “Waystations” for declining monarch butterflies, and 283,000 wildlife gardens certified by the National Wildlife Federation. What’s more, the interest in conservation gardening is growing. “In 2020 we saw a 50 percent increase in people creating and certifying wildlife gardens,” says Mary Phillips, head of the National Wildlife Federation’s Garden for Wildlife program. In the past two years, she adds, that number has held steady.
In 2001, before starting her PhD, Susannah Lerman, of the Forest Service, was driving around Phoenix through desert and residential areas when she had a revelation. Back then, she says, biologists saw the struggle to preserve nature as an epic clash between cities and rural wildlands. They were convinced that “the wild places are where all the biodiversity is, and urban development is bad,” Lerman recalls. “I came to this realization that we can’t stop urban development so we need to figure out how to make it less bad.”
Twenty-plus years and a doctorate later, she is one of the pioneers of conservation gardening research. “There are hundreds of papers now that look specifically at the conservation role that residential yards can play,” she says.
In their five-year NSF study, Lerman and her colleagues analyzed the differences in breeding bird use of private yards and natural areas in parks in Baltimore, Boston, Miami, Minneapolis-St. Paul, Phoenix and Los Angeles. The yards were either typical lawn-dominated suburban properties or were managed for conservation. Many of the latter landscapes were wildlife gardens certified by the National Wildlife Federation.
The highly maintained lawns tended to host common “generalists,” such as house sparrows and house finches, which are not fussy about food and nesting places and therefore thrive in disturbed urban areas. In contrast, rarer “specialist” birds with specific food or cover requirements were found in the certified yards, including species of conservation concern such as curve-billed thrashers in Phoenix and wood thrushes in Baltimore. In addition, while similar collections of birds were observed at lawns across most of any given city, and to some extent even across the country, different bird species often turned up in each certified yard because the plants in them varied, creating a variety of habitat niches. Lerman points out that this diversity, combined with the synergistic role that the home conservation gardens can play in bolstering urban wildland fragments, indicates they have the potential to help reverse the loss of biodiversity in urban areas.
“There is no downside to growing appropriate native plants in urban landscapes,” says a conservationist.
Studies suggest that conservation gardens can be a boon to native flora as well as fauna. In a paper published in Nature Sustainability in May, researchers in Germany, Portugal, and the Czech Republic note that global measures for saving plants, most notably by safeguarding habitat in large protected areas, “have failed to halt systematic widespread declines in plant species.” While these efforts are key to successful plant conservation, they add, new approaches are urgently needed. The new approach they propose is to mainstream conservation gardening.
Using Germany, where 70 percent of plant species are in decline, as a case study, the scientists documented how horticulture has already played a key role in the recovery of some species. In recent decades, for example, planting in home gardens has increased the total numbers of two natives: grape hyacinth, classified as vulnerable on the German Red List of threatened species, and common bluebell by 65 and 1,104 percent, respectively.
In Germany, as in other countries, several obstacles are slowing the continued growth of conservation gardening and decreasing its ecological value. One stumbling block is that the native-plant industry caters primarily to the needs of large-scale ecological restoration. And while the demand for natives in consumer horticulture has grown, the emphasis has been on producing “nativars,” specimens with unusual ornamental traits — showy flowers with extra petals, say — and using propagation techniques such as cloning that preserve the desired characteristics but diminish the plants’ genetic diversity and resilience. The authors of the Nature Sustainability paper recommend labeling standards to make it easy for nonprofessionals to identify plants suitable for conservation gardening.
“There is no downside to growing appropriate native plants in urban landscapes,” says Polly Weigand of the Long Island Native Plant Initiative. “It is only beneficial.”
On a crisp, sunny day in November, bumblebees feasted on late-season nectar and pollen from brilliant goldenrod blooms in one of Anthony Marinello’s residential gardens, a pocket prairie backed by a white picket fence on a quiet suburban block in Floral Park at the western extreme of the historic Hempstead Plains. Every afternoon the garden “is completely filled with songbirds eating the seeds,” he says.
Conservation gardens such as this can provide the vital connective tissue that enables ancient natural communities to survive and even thrive. Brimming with native grasses, sundrops, dotted horsemint, and other wildflowers, the pocket prairie can help link the Hempstead Plains and other patches of sandplain grassland that dot the south shore of Long Island east to its terminus at Montauk Point. “You can’t knock down the shopping malls and subdivisions,” Marinello says, “so we need to incorporate these species back into our landscapes.”