Restoring the Ecosystem One Native Garden at a Time

Native plant garden at Princeton University.

Public and county parks, school gardens and municipalities, landscape architects and backyard gardeners are all reaping the benefits of planting native

By Ilene Dube

From language and literature to the culinary arts, influences from around the world add flavor to our lives. But when it comes to the plant kingdom, specimens from afar can wreak havoc on the ecosystem.

Exotics, sometimes called non-native invasive species (although that term can take on a negative connotation), often outcompete native plants — plants that grew in the Americas before colonization. They can take over resources, proffering the wrong kind of food for the native wildlife.

The case for native plants can be summed up in the words of environmental farmer Jake Fiennes (brother of actor Ralph Fiennes), who was recently profiled in The New Yorker: “How do we feed the nine billion?” he asks. “Through functioning ecosystems…cultivate as much on the land — fungi for the soil, grasses for the pollinators, weeds for the insects, insects for the birds…”

Happily for the planet, landscape architects and horticulturists are increasingly populating public parks and spaces with native plants. Even New York’s Fresh Kills Park, built on the site of a former garbage dump, is being planted with natives.

Mercer County Park Commission

Betsey Stockton Garden

With Betsey Stockton Garden, Princeton University has chosen to make a bold statement in support of native plants right alongside its main gates. The public pocket park was planted in September 2018, and its willowy grasses and flowering plants dancing in the winds are just coming into their prime.

Princeton University Landscape Architect Devin Livi refers to the space as a “naturalized garden.” It actually serves as a green roof for a 1971 underground addition to Princeton’s Firestone Library, according to Dan Casey of the University Architects office. Three feet of undulating soil covers the library roof, with Louise Nevelson’s sculpture Atmosphere and Environment X a centerpiece. That title is fitting for the public space as well, with Adirondack chairs that welcome visitors to sit and contemplate. At this mid-winter writing, the dried stems gave structure to the garden, allowing a visitor to experience the seasons — something a mown lawn would not do.

The garden was named for Betsey Stockton (1798-1865) as part of a campus initiative to recognize and honor a more inclusive set of people who make up the University’s history. Sources suggest that Betsey Stockton was born into slavery in the Princeton household of Robert Stockton. While a young child, she was taken from her mother and placed in the Philadelphia household of Robert Stockton’s daughter Elizabeth and her husband, the Rev. Ashbel Green, a University president in the early 1800s.

After her emancipation, Betsey Stockton became the first African American and first unmarried female missionary to Hawaii. She was also a prominent and respected educator in Philadelphia and Princeton, as well as a founder of the First Presbyterian Church of Colour of Princeton, now known as Witherspoon Street Presbyterian Church.

A sign in the garden commemorates Stockton, and one can only imagine what she might think of this somewhat wild space, surrounded by glass skylights illuminating the library’s subterranean reading rooms. Livi admits he’s received phone calls asking about the “weeds.” Casey acknowledges the need for signage to educate visitors about the plantings.

The low-maintenance garden, started from seed plugs, will require a once-a-year cutting, as well as monitoring and removing invasives. “It will keep changing and evolving,” says Livi. “Some plants will come into their own as others die off.”

At the University’s Butler tract — formerly housing, bounded by Harrison Street, Hartley Avenue, and Sycamore Road — Livi’s crew has planted meadow mixes and native plants. “It’s been a great experiment, an opportunity to learn and a sustainable way to maintain the property,” he says. “We’ve been amazed at the insect life — lady bugs and praying mantises that eat the aphids.”

For the foreseeable future, Casey says, the Butler tract will remain undeveloped. Livi is anticipating the arrival of pollinators to the Betsey Stockton Garden as the plants develop during the growing season.

The sustainable plantings and amended soil at Betsey Stockton Garden also allow for better drainage and stormwater management. Throughout campus Livi is investigating habitats that are more sustainable than mown lawns.

Betsey Stockton Garden was designed by Michael Luegering of Michael Van Valkenberg Associates, selected as Firm of the Year in 2016 by the American Society of Landscape Architects, with clients such as the Brooklyn Botanic Garden, Brooklyn Bridge Park, and the landscape for the Obama Presidential Center in Chicago. Hallmarks of MVVA design include curving paths and constructed hillocks.

Plant selection was based on a combination of practical measures and sensory experiences, says Luegering. “We started with a hearty base of grasses that had variegated root zones, some tap roots with clump forming habit, others with shallow root zones that are rhizomatous, meaning they ‘creep’ around the site. This helped ensure we could manage early weed growth by quickly covering open soil with the added effect of retaining soil moisture” and lessening the burden on water resources.

“These grasses are often very beautiful in their own right,” Luegering continues. “Little bluestem turns a beautiful burgundy, almost blue, in the fall as it enters dormancy, while sideoats subtle seed hulls turn a bright red just around the time they release seed.”

Accompanying the grasses are flowering annual and perennial plants that were selected for both their bloom time, bloom color, and height so that new drifts in the meadow would come alive throughout the year. The plugs used to create these drifts were laid out to guide the eye as you walk through the rolling hillocks.

Deep shade and shadow patterns were addressed by “a second plant palette that is highly adapted to shade so as to ensure that similar colors and forms would be seen across the roof in both sun and shade,” says Luegering.

Purple Milkweed

Morven Museum & Garden

On the other side of Nassau Street, Morven Museum & Garden is growing its native plantings. “The most concentrated group of natives are in the Commodore’s (Robert Fields Stockton) glasshouse area,” says horticulturist Louise Senior.

“The Commodore’s glasshouse area was where Morven’s owner in the 1850s built a heated greenhouse,” says co-horticulturist Charlie Thomforde. “It is now completely gone. Based on archaeology, the footprint of the building is outlined with brick.”

“Last summer we planted it primarily with natives,” says Senior. “Within the footprint of the glasshouse is native pachysandra (Pachysandra procumbens). It’s also called Allegheny spurge, and makes an interesting comparison to the widespread Asiatic and perhaps overused pachysandra we see throughout our region. It’s very deer and drought tolerant.”

Among the other plantings are fall-blooming wood asters to attract late season pollinators. The low mounding groundcover is good in shady areas — “the white flowers gleam and light up shade,” says Senior. There are lady ferns, woodland phlox (a spring bloomer that adds a “splash of blue/purple”), Virginia bluebells (a magnet for early spring butterflies; “bees like it too, but the tubular flower shape makes pollen difficult for the bees to access”), and mini Solidago, more commonly known as goldenrod, a “wonderful long blooming late summer/fall perennial that is not an allergen,” Senior clarifies.

Other natives are intermixed with the perennial border along the brick wall, such as coneflowers and goldenrod.

One might guess that in re-creating the Colonial gardens of the Stockton family at Morven, plantings might pre-date the arrival of exotics, but that’s not necessarily the case, says Senior.

“Even ‘the Signer’ (Morven resident Richard Stockton, who signed the Declaration of Independence) brought plants home from England for his wife, poet Annis Boudinot Stockton,” she says. “Also, the continued use of the property, especially by the families of Robert Wood Johnson and the governors, led to a full re-landscaping. Helen Hamilton Shields Stockton also extensively re-landscaped. Though Helen told romanticized versions of how old plants were at Morven, I do not think we have any actual pre-1890s herbaceous plants.”

NPS Garden

Mercer County

Mercer County is working aggressively to restore native landscapes to benefit both people and wildlife, according to the office of County Executive Brian M. Hughes. This includes practicing good stewardship and native landscaping on county-owned lands to supporting municipal partners and training Mercer County residents on how to establish wildlife-friendly landscapes at home.

“With more than 10,000 acres of open space and parkland under our care, Mercer County and the Mercer County Park Commission are uniquely positioned to implement large landscape-scale native plant restoration projects,” says Hughes. “With the strong support of Mercer County voters, Mercer County’s dedicated Open Space Trust Fund is utilized to support high quality habitat restoration in a variety of locations throughout the county.”

Among the projects is the Grassland Restoration at Mercer Meadows in Lawrence and Hopewell townships. “Over the past decade the Park Commission has converted 435 acres of land into regionally significant native grasslands, which host a variety of grassland breeding birds — one of the bird communities that is most imperiled in the United States,” says Hughes. “This winter, a prescriptive burn will take place in a portion of the area to reduce invasive shrubs and stimulate growth of more native grasses and wildflowers.”

Other county restoration projects are at Fiddler’s Creek Preserve in Hopewell, Freshwater Tidal Wetland Restoration at Roebling Park in Hamilton, and Riparian Corridor Restorations at Moore’s Creek and along the Stony Brook in Rosedale Park in Hopewell.

Mercer County Park Commission Executive Director Aaron T. Watson has adopted a “Do Not Plant List” directing land managers not to use invasive plant species in landscaping on county lands.

And a county initiative is underway to help establish pollinator meadows and native landscapes on schoolyards and other public municipal lands.

“These projects help to connect large-scale parkland and open space and ensure that we can perform land restoration in all of Mercer County’s municipalities, even where we don’t own or manage parkland,” says Hughes. “Understanding that our wildlife species do not see or abide by political boundaries, we must look beyond our own county-owned parkland to meet our goal to protect pollinator species, migratory birds, and local wildlife that depend on our natural landscapes.”

The County Open Space Trust Fund finances the installation of “pop-up” wildflower meadows on municipal land, resulting in the conversion of manicured lawn into a diverse native meadow. The first pop-up meadow is in Ewing Township, with others in the planning. “Our goal is to increase pollinator habitat, reduce the environmental costs of maintaining lawns, and educate the public on the benefits of natural meadows,” says Hughes.

The Park Commission is also helping to establish Schoolyard Sanctuaries, giving technical support to school districts seeking habitat restoration on school grounds.

While the European honeybee is commonly associated with crop pollination, it is the 4,000 native bee species that have the most significant impact.

“Pollinating insects such as native bees and honeybees play vital roles in all of our ecosystems and in agriculture and food production, but their populations are decreasing at an alarming rate,” says Hughes. “Creating new habitat that provides pesticide-free pollinator food sources is a step we can take at the local level to promote the county’s long-term prosperity and sustainability.”

According to the Xerces Society for Invertebrate Conservation, 165 insects are critically imperiled and up to 29,000 are at risk in the U.S. due to habitat loss, overuse of chemical pollutants, and displacement by non-native species.

In addition to creating more pollinator habitat throughout the county, wildflower meadows decrease landscape and site maintenance time and costs. Replacing lawn with meadow reduces the need for regular mowing, thereby decreasing the emissions produced. It also eliminates fertilizer use, and drastically reduces the amount of chemicals applied to typical lawns.

American Persimmon

Mountain Lakes Nature Preserve

In Princeton’s Mountain Lakes Nature Preserve, Friends of Princeton Open Space (FOPOS) is restoring a degraded woodlands area with native plants.

“The pressures posed by the overabundance of white-tailed deer is a driving force behind forest degradation in our area,” says the FOPOS website. “Large herd sizes combined with limited foraging habitat has led to severe over-browse of native tree saplings, ultimately hindering forest regeneration.”

A fenced deer enclosure area serves as a conservation zone and native plant nursery that offers refuge to threatened plant species, produces seed for native plant propagation, restores the soil seed bank, and secures the future tree canopy by protecting native tree seedlings.

The restored site will provide habitat for birds, pollinators, mammals, and other wildlife, while providing an enhanced experience for hikers, runners, bicyclists, birdwatchers, and other park users. Planting is expected to begin in spring.

Larry Koplik, standing next to a tall grove of New York Ironweed.

Native Plants Offer Benefits to Humans, Too

Ah, to have a lush native plant garden just outside the window, a la Dutch landscape artist Piet Oudolf, whose gardens at the High Line in New York City are based on the wild plants that once grew on the former rail bed. But while inspired by natural landscapes, Oudolf’s gardens bend the strictest of native plant gardening rules.

Sarah Roberts, along with her husband Larry Koplik, began planting natives on their Montgomery property after reading Leslie Sauer’s The Once and Future Forest.

Sauer recommended taking an inventory of plants in a forest by following a straight line and recording everything you find, recounts Roberts. “I went out to our three acres of woods with a clipboard and wrote down the species and size category of each tree on a straight line, and noticed that half were ash trees, many were dead or declining, and most of the seedlings were also ash. I realized that, at this rate, we’d soon run out of trees, so I determined to plant a wide variety of trees. I’d been reading that native plants were good for wildlife, so I only planted native trees.”

Sarah Roberts

Roberts and Koplik planted persimmon trees, pawpaws, white oaks and swamp white oaks, pin oaks, red oaks, scarlet oak, willow oaks, shagbark hickories, tupelos, sassafras, basswood, American hornbeam and hop hornbeam, tulip trees, fringe tree, sycamore, river birch, sweet gum, and white pine and Virginia pine.

“All are native, though some have non-native relatives with the same name,” says Roberts.

Roberts deserves the sobriquet “The Woman Who Planted Trees.” She recently scattered native flower seeds in the woods and stream corridor that she takes care of in front of Village School in Skillman Park, and she plants milkweed in front of Montgomery’s Municipal Building to provide food for monarch butterflies.

“Some of my favorite plants are pawpaw and persimmon trees,” she says. “I also love Virginia bluebells, mayapples, trout lilies, spring beauties, violets, golden ragwort, golden alexanders, and native wild geranium, which bloom at the same time and look lovely together.”

Native plant names flow from her lips like honey from the hive: Canada lilies and Turk’s cap lilies, wild senna, goldenrod, Physostegia virginiana, swamp milkweed, butterfly weed, purple milkweed, and Joe Pye weed.

The payoff? “We’ve seen some hummingbirds at the Canada lilies, and lots of tiger swallowtails at the Joe Pye weed,” says Roberts. “The mountain mint is just covered with bees when it blooms, and the Physostegia has bees crawling into its flowers. We have hummingbird moths, too, and butterflies, moths, spiders, and beetles. We have a good-sized vernal pool in our backyard, which is filled with many varieties of frogs and some salamanders, and sometimes we get great blue herons and green herons hunting them. Several years in a row we have had a mourning dove nesting on the pergola on our deck.”

This keeper of the earth gives away pawpaw trees “free to a good home” that she grows from seed.

“Pawpaw trees are native to New Jersey, and threatened in the wild, though they grow well in people’s yards. They bear the largest fruit native to North America, which is delicious, and they’re somewhat deer-resistant. They are also host to the beautiful zebra swallowtail butterfly, which is extinct in New Jersey. For all these reasons I would like to re-populate New Jersey with pawpaw trees — to bring back an endangered native tree, to provide fresh fruit, for landscaping, and, if we plant enough pawpaw trees, we can bring back the butterfly, which is found in other states.”

Native Plants Featured in the Betsey Stockton Garden
(Some are used on the High Line as well.)

Grasses:
Carex comosa, Appalachian Sedge
Carex pensylvanica, Pennsylvania  Sedge
Festuca ovina, Sheep’s Fescue
Festuca rubra, Creeping Red Fescue
Sporobolus heterolepis, Prarie Dropseed
Elymus virginicus, Virginia Wild Rye
Schizachyrium scoparium,
Little Bluestem
Tridens flavus, Purple Top

Shade Plants:
Aqueligia canadensis, Wild Columbine
Aster laevis, Smooth Blue Aster
Blephilia ciliata, Downy Wood Mint
Erigeron puchellus, Robin’s Plantain
Eurybia divaricata, White Wood Aster
Polemonium reptans, Jacob’s Ladder
Sisyrinchium angustifolium, Narrow Leafed Blue-Eyed Grass
Solidago caesia, Blue-stem Goldenrod
Solidago flexicaulis, Zig-Zag Goldenrod

Full-Sun Plants:
Asclepias tuberosa, Butterfly Milkweed
Aster laevis, Smooth Blue Aster
Aster pilosus, Heath Aster
Baptisia alba, White Wild Indigo
Baptisia perfoliata, Catbells
Centaurea cyanus, Cornflower
Chamacaesta fasciculata, Partridge Pea
Coreopsis lancelota, Lanceleaf CoreopsisEchinacea pallida, Pale Purple Coneflower
Echinacea purpurea, Purple Coneflower
Monarda fistulosa, Wild Bergamot
Penstemon digitalis, Beard Tongue
Rudbeckia hirta, Blackeyed Susan
Solidago juncea, Early Goldenrod