The du Pont family has had huge impacts on Delaware’s economy, politics and culture. Less famous are the legacies of the descendants of Éleuthère Irénée du Pont – who described himself as a botanist when he emigrated from France – on the local environment.

That force is best illustrated in the rolling hills northwest of Wilmington, nicknamed Chateau Country for its grand (du Pont) estates, with much of the impact marked off in a map prepared by the Brandywine Conservancy, which was co-founded by George A. “Frolic” Weymouth, whose mother was a du Pont. The colored areas of the map mark various kinds of protection.

The conservancy’s campus has a landmark museum on Route 1 in Chadds Ford, and its land and other protected land (colored light green) spread south along the Brandywine into Delaware. To the east is First State National Historical Park, in dark green.

Also light green are Winterthur (once Henry Francis du Pont’s estate) and the Bidermann Golf Club (once Henry’s private golf course). Also key are the Mt. Cuba Center (once the home of Lammot du Pont Coepland and his wife Pamela, not on the map) and the Ashland Nature Center (also off the map) and Coverdale Farm Preserve (partly shown on the left of the map), of the Delaware Nature Society.

“Preservation has always been a cornerstone” at Winterthur, said CEO Chris Strand. “Our board of trustees has defined our strategy this way: “ ‘It is Winterthur’s policy to conserve this design for posterity while recognizing the elements of change inherent in living organisms.’ ”

Parks and other preserved public land, in light blue, include Brandywine Creek State Park (once a du Pont family dairy farm), Alapocas Run State Park and Rockford Park south of Hagley, Valley Garden Park (donated by Ellen du Pont Wheelwright) and Hoopes Reservoir west of Hagley and Flint Woods Preserve (sold to the state at a discount by Lucille du Pont Flint and north of Winterthur).

Country clubs with lots of plantings are tan, including the Wilmington Country Club (more of Henry’s land, with the club maintaining an orchard that dates to 1932) and the DuPont Country Club (for 98 years a club owned by the company and since 2018 now co-owned by Ben du Pont and Don Wirth) and the Brandywine Country Club (likely to be developed).

The future for Granogue

The biggest influence not named du Pont is William Poole Bancroft, who combined the money from his milling business and his caring for society from his Quaker values to create Woodlawn Trustees. Woodlawn once owned the Beaver Valley Tract that forms most of the national park.

Woodlawn also owned the 270-acre Beaver Valley property (in burgundy on the map), and Bancroft and Woodlawn donated land for Alapocas Run, Brandywine Creek and Rockford parks.

In the middle of all this preserved land is a label for Granogue, another du Pont estate, along Smith Bridge Road. In February, Longwood Gardens (founded by Pierre S. du Pont to preserve an arboretum) announced that it is purchasing and preserving Granogue.

“This acquisition ensures that its forests, meadows and agricultural lands forever remain a pastoral landscape,” Longwood said on Facebook when it announced the arrangement.

Irénée “Brip” du Pont Jr. (E.I.’s great-great-grandson) lived on the 505-acre Granogue with his wife Barbie. Although Longwood and the du Ponts started talking in 2016 about the deal, the closure process could take up to a year from the announcement.

“We have no immediate plans to activate the property,” Longwood spokeswoman Patricia Evans said. “This acquisition, when finalized, is first and foremost an act of conservation.”

Granogue, besides the famed mansion, has lots of acreage actively farmed for corn, soy, hay and dairy production, with large sections of forest, pasture and meadow.

“Preserving an extraordinary property for enjoyment for all of us,” Ben du Pont wrote on Facebook.

Bigger is better

Land preservation is the antithesis of development, but preserved land is still used by humans in multiple, limited ways, such as farming and recreation. Land is preserved to benefit the flora and fauna that live there, and it also benefits the humans who drink and use the water that flows through it.

University of Delaware professor Doug Tallamy came up with the concept of a “homegrown national park,” where united individual homeowners create large beneficial landscapes.

Larger tracts offer better benefits, experts agree. “Contiguous habitat – aka properties that touch each other – is essential to conservation because it creates safe passage for animals that live there,” Mt. Cuba writes on a page on its site titled “Protecting Natural Lands. The page says that Mt. Cuba has protected 13,000 acres in the mid-Atlantic, via funding and partnerships.

Delaware started protecting public lands in 1927, with the creation of Redden State Forest. The 1990 Delaware Land Protection Act set up the Open Space Program to conserve lands “with the best natural resources, cultural resources and outdoor recreation value,” said spokeswoman Shauna McVey. Since then, 65,124 acres have been preserved, with a focus on land near or next to state parks.

“We are managing to create a diversity of habitats to support a wide range of species native to the area and that migrate through the area,” said Jeff Downing, executive director of Mt. Cuba Center.

“It’s hard to partition conservation,” he said, referring to purple martins, whose migratory range includes much of North and South America.

“Our bigger mission is to inspire the community to appreciate the value and beauty of native plants and help participate in conservation,” he said. Mt. Cuba also helped with funding to buy Granogue.

What Mt. Cuba Center does (and does not)

Mt. Cuba, which opened to the public in 2013, in 2018 merged with the Red Clay Reservation, a nonprofit started by neighbor H.B du Pont in the 1960s. Mt. Cuba manages 1,000-plus acres, some in its impressive cultivate gardens around the main house, but most a series of natural environments.

Management takes multiple forms. The most obvious involves planting, such as the stretches where saplings are growing to expand the forest, a patch where chestnut trees are being studied for their ability to fight blight and a 10-acre tract where this year they planted 24 million seeds of 39 native species to create a natural-looking meadow to support pollinators.

Management also involves removing, such as weeding invasive plants, mostly by hand and with limited spot treatment by herbicides (but never pesticides). Removals can be more dramatic, such as a now-eliminated hedgerow that expanded a meadow and immediately drew more ground-nesting birds, such as northern harriers, red-winged blackbirds and sparrows.

Removals can be less dramatic, such as harvesting hay, and selling it for use elsewhere, which strategically reduces nitrogen accumulated when the fields were intensely farmed, Downing said.

Management also involves monitoring. Every few years, Mt. Cuba assesses the flora at 84 spots. And surveys of fauna have found 15 species of native bees not previously known to occur in Delaware, including the Jacob’s ladder miner bee, 365 miles from its nearest known population.

Sometimes management involves doing nothing. Stumps of dead trees are left in the ground as habitats for insects and other creatures, and brush piles on land and even in the water provide homes for small mammals, like rabbits, and fish.

“It’s easy to forget or take for granted the beauty of our region,” said Stephanie Sturmfels, marketing manager for the Delaware Nature Society. ”The pandemic highlighted how important places to spend time in nature are to so many people.”

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HOW THEY’RE PRESERVING (AND HOW YOU CAN SEE THE WORK)

Brandywine Conservancy: The conservancy holds more than 510 conservation and agricultural easements and has facilitated the permanent preservation of over 70,200 acres – including over 1,900 acres in Delaware, which mostly support farming. The group, based in Chadds Ford, is a leader on the Brandywine Creek Greenway, a 40-mile conservation and recreation corridor along both branches of the Brandywine, boasting over 36,000 acres of protected open space.

Delaware Nature Society: The society manages nearly 2,000 acres in Delaware, including 1,400 in New Castle County. Some properties can be explored only on programs; others have trail access daily dawn to dusk. One key tract: Coverdale Farm Preserve, near Greenville, with 200 acres of restored native meadows, forest and stream valley, plus a 177-acre farm. Volunteers help monitor nearly 200 nest boxes, participate in tree planting, control invasive plants and help with other activities. Areas protected for the long term protect waterways that supply drinking water to thousands and “mitigate against the impacts of climate change by reducing flooding, supporting wildlife, sequestering carbon and reducing temperatures,” said marketing manager Stephanie Sturmfels.

Delaware State Parks: The division manages more than 2,000 acres in northwestern New Castle County, including Alapocas Run and Wilmington state parks (521 acres), Auburn Valley State Park (471), Brandywine Creek State Park (955), Flint Woods Nature Preserve (143 of the preserve’s 217) and Tulip Tree Woods Nature Preserve (24). Brandywine Creek’s rolling meadows provide habitat to native pollinators, ground-nesting birds and rare native plants. Those “open meadows are excellent for picnics, kite flying, and disc golf, and in the winter, for sledding and cross-country skiing,” the park’s website says, noting the park maintains trails for fitness, wildlife observation and photography; stocks Wilson’s Creek with fish; runs canoeing and other interpretive programs; and hosts outfitters that rent canoes, kayaks and tubes for rides down the Brandywine.

First State National Historical Park: The Beaver Valley tract east of the Brandywine covers 1,100 acres, some farmed, with miles of trails for hiking, biking and horseback riding. Woodlawn Trustees developed the trails and amenities when it owned that land, and it still owns a lot of acreage to the east.

Longwood Gardens: The gardens cover 1,100 acres, with 750 in forests, fields, streams, meadows and wetlands, and of that, 100 acres that can be explored via trails. The acreage supports more than 200 species of birds and more than 760 species of native plants. Longwood researches environmental change and tests land management practices. It is also taking over the 505-acre Granogue estate.

Mt. Cuba Center: Mt. Cuba conserves more than 1,000 acres of natural lands – including meadows, forests, streams and riparian corridors – surrounding its manicured gardens. Its long-term plan includes moving its main entrance to Old Wilmington Road, for easier access for buses. Trails cross the natural lands, with benches for resting and water-bottle-filling stations for hydration. The center has been involved in protecting more than 13,000 acres in the mid-Atlantic.

Winterthur Museum, Garden & Library: Winterthur’s 978 acres are protected by an easement with the Brandywine Conservancy, with half naturalized meadow and a fifth woodland. Founder Henry Francis du Pont “loved the rolling hills of the Brandywine and intended to preserve them so that people could enjoy them,” said CEO Chris Strand. “The garden is crisscrossed with paths that encourage exploration. And we offer walks and programs that equip people to explore the landscape.”