In 1924, the Arnold Arboretum’s first director, Charles Sprague Sargent, named a new hybrid buckeye, Aesculus × dupontii, in the Journal of the Arnold Arboretum and praised the tree’s namesake, the du Ponts, for making the vicinity of Wilmington, Delaware, “one of the chief centers of horticulture in the United States.” The family’s fortune had exploded from the manufacture of gunpowder in the nineteenth century and was enriched further by chemicals in the twentieth. The resources the du Ponts dedicated to their landscapes made Delaware’s Brandywine Valley a must-see destination for horticulturists who travel there to visit and study at the estates that are open to the public today.

Longwood Gardens, just over the Delaware border in Kennett Square, Pennsylvania, is the most visited, with its Italianate and French neoclassical fountains, lightshows, and fireworks that elicit audible “oohs” and “ahhs” from large crowds at all seasons of the year. Its creator, Pierre S. du Pont, was inspired by the spectacle and sense of wonder he experienced, at age six, when he attended the Centennial Exhibition in Philadelphia in 1876. His grand conservatories of hothouse plants continue to wow his posthumous guests, especially when decorated for Christmas, as does a garden amphitheater that hosts evening concerts and Shakespeare plays performed in a veritable Forest of Arden. Closer to Wilmington, his cousin Alfred I. du Pont spent a large fortune to build Nemours, with gardens modeled after Versailles. And Mt. Cuba, the estate of Lammot du Pont Copeland and his wife, Pamela, would become a display garden and research center for studying the native flora of the Piedmont.

Of the estates that earned northern Delaware the sobriquet “chateau country,” Henry Francis du Pont’s Winterthur Museum and Gardens is the most naturalistic. Home to nearly a thousand acres of rolling meadows, forests, and one of the finest woodland gardens in the world, Winterthur’s connections to the Arnold Arboretum are deep. To walk the curving pathways through its woods and fields is to see a landscape shaped by what H. F. du Pont learned in Boston and through collaboration with the Arboretum’s collectors and propagators over decades.

Black-and-white photograph of Bussey Institution
Du Pont studied horticulture at Harvard’s Bussey Institution, which was located on South Street, adjacent to the Arnold Arboretum. Arnold Arboretum Archives

In an affectionate yet frank book about Winterthur (pronounced “winter tour,” meaning “winter’s door”), H. F. du Pont’s daughter Ruth Lord claimed that her father found his life’s calling at the Arboretum. As a student in his junior year at Harvard, in 1901, du Pont applied for admission into classes at Harvard’s Bussey Institution, one of the first formal university programs to teach horticulture in America. Its mission, according to the Bulletin of the Bussey Institution, was to educate “young men who intend to become practical farmers, gardeners, florists, or landscape gardeners,” as well as “men who will naturally be called upon to manage large estates.” Young du Pont was destined to become all of those things. But by October, the fall semester had already begun. He was late and had an unimpressive academic transcript. The coursework was rigorous, taught by scientists with little patience for dilettantes. Still, he was admitted with the expectation that he could catch up. He wrote to his mother of his “sudden resolution … my great desire to really know something about flowers … In fact flowers etc. are the only real interests I have.” He added, “I do not think I am impulsive I hope not at least. I merely think it is the smouldering [sic] of latent thought which has burst into flame.” In his first course, Horticulture I, taught by Benjamin Marston Watson, who led Harvard’s horticultural instruction program for almost forty years, du Pont received a D-. The student would turn out to be a late bloomer.

From that unpromising beginning, H. F. du Pont went on to become one of the most accomplished horticulturists of the twentieth century, a man the Garden Club of America in 1956 designated as perhaps “the best gardener this country has ever produced” up until that time. He also served as an important benefactor of the Arboretum and would consult with its staff over the next seven decades.

Scion of a Distinguished Family Tree

H. F. du Pont (or “Harry,” as his family called him) was born in 1880, “with a silver trowel in his hand.” He was the son of Henry Algernon du Pont, the richest man in Delaware; grandson of Henry du Pont, the longest-serving chief executive of the E. I. du Pont de Nemours Company; and great-grandson of the company’s founder, Éleuthère Irénée du Pont, who arrived in America with three generations of du Ponts in 1800. E. I. du Pont settled his family and established his powder works on the bank of Delaware’s Brandywine River. There, at what he named Eleutherian Mills, he laid out a French parterre, with fruit orchards and potager to feed his family. He imported trees from Europe and instilled in his children and grandchildren a love of horticulture and an interest in agriculture and animal husbandry.

E. I. du Pont purchased the first acres of what would become Winterthur with gunpowder profits from the War of 1812. H. F. du Pont’s father inherited the property in 1889. By then, Winterthur had sprawled to 1,135 acres. As children, H. F. du Pont and his older sister, Louise, had the run of the outdoors, with farm animals for companions: goats, sheep, poultry, and forty draft horses. In her late seventies, Louise recalled to Winterthur curator John Sweeney how her father drilled into them his interest in botany, and the process of learning through careful observation: “Father would take Harry and me by the hand and walk through the gardens with us, and if we couldn’t identify the flowers and plants by their botanical names, we were sent to bed without our suppers.”

If their father, first in his class at West Point in 1861, was pompous and rigid, their mother, Pauline Foster, was warm and tender. Having lost five of seven children in infancy, she kept her son close and passed on to him her love of flowers that she shared with her mother-in-law, Louisa Gerhard du Pont, and other du Pont relatives. Pauline was the daughter of a gentleman farmer in New York, and she impressed upon her son that Winterthur was not a showplace but a country place, a retreat for repose. H. F. du Pont was shy as child and awkward around peers in his youth (he spoke only French when he first entered school), and he would credit his mother with his lifelong desire to reinforce the feeling of “great calm and peace” that Winterthur provided in his anxious childhood.

At age thirteen, H. F. du Pont was sent off to boarding school at Groton, Massachusetts. From letters to his parents, he hated being away and consoled himself with visual memories of home. He wrote of his joy at recognizing Winterthur’s May-blooming Brandywine bluebells (more commonly known as Virginia bluebells, Mertensia virginica) in Gray’s Manual of Botany. When he begged for permission to work in the nurseries of a garden center near the school, du Pont’s parents fretted over their son of the manor getting his hands dirty and rubbing elbows with workingmen in Groton. But he had already performed chores for Winterthur’s gardeners, who decades later would remark that du Pont could work as hard physically as any paid laborer.

Student at the Bussey Institution

After entering Harvard in 1899, du Pont reconnected with a childhood acquaintance, Marian Coffin, one of two women enrolled in the new landscape architecture program at the Massachusetts Institute of Technology. (Harvard did not admit women at the time.) Coffin’s mother and du Pont’s mother were close friends. It was Coffin who had urged du Pont to take courses at the Bussey Institution. Together, they studied in the Arboretum under John George Jack and toured Holm Lea, Sargent’s 150-acre estate in Brookline, on the north side of Jamaica Pond. There, du Pont expected to find mature trees of enormous size but wrote home with disappointment that he saw only two, although he noted that “the Magnolias around the pond were in full bloom and magnificent.”

Sepia photograph of three young adults sitting on staircase with picnic items arrayed around them
H. F. du Pont relaxes in the Winterthur landscape, in 1904, with Marion Rawson and cousin Elaine Irving. Courtesy of Winterthur Library: Winterthur Archives

Coffin found in Sargent a mentor who had already taken under his wing the early female pioneer in landscape architecture, Beatrix Jones (Farrand). Coffin’s program at MIT, under the direction of Sargent’s son-in-law Guy Lowell, emphasized geometric gardens in the neoclassical tradition. Homeschooled before college, Coffin found the heavy math requirement daunting. She credited Sargent with encouraging her to persevere, effectively saving her career at a critical moment of self-doubt.

The death of du Pont’s mother in his junior year made him return home and spend his senior year helping his father run the household and its staff. After graduating, Coffin and du Pont would tour the great gardens of Europe together, with her mother as chaperone. In an era when few firms would hire a woman landscape designer or have one supervise all-male crews, Coffin struck out on her own. Du Pont, meanwhile, would become a valuable client and steer business her way. He put off planned studies in New York’s Hudson Valley, at the School of Practical Agriculture and Horticulture in Briarcliff Manor, and began to apply at Winterthur the knowledge he had acquired at the Bussey Institution, experimenting with plants, observing how they performed, and carrying with him a notebook everywhere he went.

He started a trial of fifty-four different daffodils and planted the ones that performed best (Narcissus horsfieldii, N. albicans, and the cultivars ‘Golden Spur’, ‘Grandee,’ and ‘Emperor’) along the banks of a stream and on hillsides, in large drifts and massed colonies, never mixing them. A Bussey course on hardy herbaceous plant materials had introduced him to the ideas of William Robinson, the evangelist for naturalistic gardens, whose book The Wild Garden, published in 1870, had revolutionized landscape design in Britain. The Irish-born Robinson was an irreverent crusader against Victorian garden contrivances, from the bedding out of tender, tropical annuals in temperate climates to the idolatry of faux Italianate ruins. Instead, Robinson advocated for the use of winter-hardy plants and natural-looking gardens “devoid of any trace of man.” Valencia Libby, who dug deeply into Winterthur’s ties to the Arboretum, unearthed a paper that du Pont wrote at Harvard (about an aunt’s estate, Virieux, which bordered Winterthur) that reveals Robinson’s strong influence on an impressionable student. Robinson had also influenced Sargent and the Arboretum’s original landscape architect, Frederick Law Olmsted.

Laconic rather than loquacious, du Pont never articulated his design principles in one comprehensive place for easy retrieval. Scholars have pieced them together from snippets he offered here and there and from the visual evidence he left behind. Above all, he strove to achieve the appearance of nature working effortlessly, with the garden fitting into the landscape “as if it has always been there,” he would say. He told visitors this design effect took a great deal of effort and was “very hard to do.”

Estate Planner, Arboretum Benefactor

In 1909, when du Pont’s father gave him control of the estate’s grounds and greenhouses, the young horticulturist began acquiring plants with the zeal of an obsessive-compulsive collector on an unlimited budget, planting twenty-nine thousand bulbs that year and thirty-nine thousand the next. He carpeted the ground beneath tulip poplars (Liriodendron tulipifera) with snowdrops (Galanthus), winter aconite (Eranthis hyemalis), glory-of-the-snow (Chionodoxa luciliae), squill (Scilla), snowflake (Leucojum vernum), and crocus (Crocus tomasinianus). In the decades to follow, he would source bulbs, herbaceous perennials, and woody plants from the top breeders and more than fifty nurseries, chief among them the Arnold Arboretum.

Over the years, Sargent evolved from du Pont’s professor and advisor into a peer and beneficiary. The du Ponts appear in Sargent’s annual reports on the Arboretum to Harvard’s treasurer beginning in 1915, when du Pont’s father, Henry A. du Pont, made a donation to fund annual operating expenses, the equivalent of almost $2,500 today. Sargent, sensing an opportunity to cultivate new patrons to sustain the institution, pursued a personal relationship. He made personal visits to Winterthur, signing its guest book nine times between 1918 and 1923, usually during April, when spring in Wilmington is in full bloom while Boston is still dreary. Sargent already knew Wilmington as the home of the wealthy botanist William Canby, who collected forty-five thousand botanical specimens in his lifetime and had accompanied Sargent and John Muir on a tour of the Appalachians. Sargent grew close to H. A. du Pont, hosting him for personal tours of the Arboretum and the Hunnewell Estate, in Wellesley, where Horatio Hollis Hunnewell had popularized the cultivation of rhododendrons, especially the red torch azalea (Rhododendron kaempferi) that Sargent had brought over from Japan. Both Sargent and H. A. du Pont were veterans of the Civil War and patrician practitioners of noblesse oblige. In the twilight of his life, H. A. du Pont called Sargent his favorite friend.

In 1916, H. F. du Pont wed the more outgoing Ruth Wales, who had grown up in New York near his former schoolmate at Groton and Harvard, Franklin D. Roosevelt. The next year, Sargent wrote a letter inviting du Pont, the one-time Bussey student, forty years his junior, to serve on the Arboretum’s governing committee, formally called the Harvard Board of Overseers’ Committee to Visit the Arnold Arboretum. “The committee appointed by the Overseers has been of very great service to me now for many years in aiding [and] … in raising enough money … to keep the establishment going, the income from the endowment being inadequate for that purpose,” Sargent wrote. “While the Committee has been of great service to the Arboretum in this way I have never gotten any horticultural or other advice from its members, and when I suggested to the overseers to appoint you as a member of the Committee it was with the idea that you should be able to help me horticulturally for in this direction I am left entirely without advice or assistance.” Du Pont would serve the Arboretum in that capacity for fifty years, until 1968, the year before he died.

Over the years, du Pont would rely upon the Arboretum’s experts for plant identification and sourcing, consulting its long-time propagator Jackson Dawson, Dawson’s successor William Judd, and later director Karl Sax. With the Arboretum dependent on donors for fundraising, Sargent was more solicitous in correspondence than his staff, replying to one of du Pont’s inquiries about the fragrant, white-blooming mock orange (Philadelphus) by writing, “If there is any particular kind you want, we shall be glad to have a plant propagated for you.” Du Pont would return to the Arboretum again and again, always with a notebook in hand, on frequent visits to see his sister who lived with her husband, Frank Crowninshield, in Boston and Marblehead. After a visit in 1923, du Pont wrote Sargent: “The only trouble in going to the Arboretum is that I come back fired to possess all kinds of plants which, as you know, are unprocurable elsewhere. After going through numberless catalogues I am absolutely stumped by the enclosed list, and I am wondering if little by little you could procure cuttings of these various shrubs, as I should so much like to have them.”

During du Pont’s first year on the Overseers’ Committee, Henry Hunnewell, son of Horatio Hollis Hunnewell, initiated a capital campaign to grow the Arboretum’s endowment. Du Pont and his father made gifts equivalent to six figures in today’s dollars. Then, in 1918 and 1919, they each provided the Arboretum with its largest annual financial gifts from individuals. The Great War in Europe had been lucrative for the family’s munitions business, and their wealth had multiplied thanks to three of du Pont’s second cousins (Pierre S., Alfred I., and T. Coleman du Pont) who had taken control of the DuPont company and engineered its expansion into chemicals and a large stake in General Motors. H. F. du Pont would plow his share into developing Winterthur, collecting antiques, and creating a summer place for his wife in Southampton, New York.

Woodland Gardener

Before the Great War, du Pont and his father visited a conifer forest that was cultivated at the Dropmore estate, in Buckinghamshire, England. The estate dated to the eighteenth century, and some of its coniferous trees had been propagated by seed brought to England by early collectors. The sight of the rare specimens inspired du Pont’s father to install a conifer collection at Winterthur. It grew to contain more than fifty different conifers recommended by Sargent and sourced by the Arboretum and thirteen commercial nurseries. Japanese umbrella pine (Sciadopitys verticillata), Japanese cedar (Cryptomeria japonica), and Atlas cedar (Cedrus atlantica) were among the selections. When laden with freshly fallen snow, Henry Algernon du Pont’s dark-green Pinetum becomes Winterthur’s own winter’s door.

While H. A. du Pont installed the Pinetum, his son worked on what would become his crowning outdoor achievement: Azalea Woods. Beginning in early spring and continuing into early summer, eight acres of second-growth tulip poplar, white oaks (Quercus alba), American beech (Fagus grandifolia), and hickories (Carya ovata) are brightened, at eye level, with hues of white, pearl, blush, pink, and red. The design was not conceived at once in any grand plan but grew organically, like seeds sprouting in niches of opportunity opened by the demise of Winterthur’s American chestnut (Castanea dentata), killed by blight.

Photograph of azaleas blooming in understory of large trees
Azalea Woods was one of the first landscapes that du Pont designed at Winterthur. It has proved an enduring masterpiece. Carter Wilkie

Among the azaleas H. F. du Pont used were seventeen Kurume hybrid azaleas he purchased during a visit to Cottage Garden Company, on Long Island. The nurseryman Robert Brown had obtained them from Yokohoma Nursery Company, in Japan, which had won a gold medal for showing them at the San Francisco Exposition of 1915. (The Yokohoma nursery had also grown the bonsai collection that Larz Anderson acquired in 1913 and which his widow donated to the Arboretum in 1937.) At Winterthur, du Pont was delighted when the new azaleas bloomed a subtle shade of pink. From these original accessions, Winterthur propagated more until their progeny spread for acres. In 1920, when Sargent wrote to du Pont with excitement about a new azalea introduction that held great promise for the nursery trade (a group of Kurume azaleas that Ernest Henry Wilson had selected from Akashi Kojiro¯, a nurseryman in Kurume, Japan), du Pont modestly avoided telling Sargent that he had been working with Kurume hybrids for three years already. From the Arboretum came Hunnewell’s Rhododendron kaempferi, and Sargent recommended royal azalea (R. schlippenbachii), praising it as “the loveliest of the hardy Asiatic Azaleas.” In the 1930s, du Pont added broadleaved rhododendron hybrids from Charles Dexter of Sandwich, Massachusetts.

Today, Winterthur’s plant database catalogues thousands of azaleas on the property, representing 252 species and varieties. The collection reaches peak bloom in Wilmington around the same time as Lilac Sunday at the Arboretum (Mother’s Day, the second Sunday in May). In bloom, the shrub layer stands out against the tall trunks and their drab bark the way Boston’s sleek John Hancock Tower, designed by I. M. Pei’s partner Henry Cobb, plays off of the hefty brown masonry of Henry Hobson Richardson’s Trinity Church. Without Trinity Church beside it, the modern glass tower could be an unmemorable building in almost any suburban office park. Likewise, without Winterthur’s trees rising out of the shrub layer like giant columns, Azalea Woods would be just azaleas, an overscaled, formless mass of color, lacking apparent depth. At the herbaceous layer, du Pont again followed Robinson’s ideas and planted great white trillium (Trillium grandiflorum), blue anemone (Anemone apennina), bluebells, bloodroot (Sanguinaria canadensis), lily of the valley (Convallaria majalis), smaller narcissi, and ferns to naturalize in colonies. While novice gardeners can be reluctant to uproot what they install, du Pont was a ruthless editor of his own work. He was a perfectionist about form and color and personally supervised the installation of trees and shrubs. In oral histories, his gardeners recalled how he would have them move a shrub mere inches to site it perfectly. He would have them plant and replant some shrubs five or six times until everything was right. Color dictated what went where. “For me, color is the thing that really counts more than any other,” he told an interviewer at age eighty-two.

Viewed through a wide-angle lens, du Pont used color to emphasize the movement of bloom sequence, which rolls across the gardens at Winterthur like slow-moving, undulating waves. By grouping flowering shrubs, he strove for harmony of related hues, or complementary colors at opposite ends of the color wheel. A signature color combination was mauve against chartreuse, which he produced by coupling two early blooming woody plants: the greenish-yellow blooms of winterhazel (Corylopsis glabrescens) with the Korean rosebay rhododendron (Rhododendron mucronulatum). He also brought outdoor colors inside the mansion, decorating rooms with fabrics and cut flowers to reflect what was visible through each window. Guests who arrived at Winterthur for the first time were bowled over by the volume of cut flowers in the public rooms. In the dining rooms, he matched table linens with the flowers and kept more than fifty patterns of china (not place settings but entire sets of china) to do the same with dinnerware. For decades, he kept meticulous notes on every table setting so that returning guests could be served on china they had not seen on previous visits.

Collector on a Grand Scale

The estate du Pont inherited in 1927, at age forty-six, spread to 2,600 acres. It contained ninety houses for the 250 or so employees working at the estate’s mansion, gardens, and farms. The self-supporting community had its own railroad station, post office, a vast complex of twenty greenhouses and potting sheds, cold frames covering an acre, huge livestock barns, a sawmill, tannery, and dairy. Descended from wealthy gentlemen farmers on both sides of his family, du Pont had been managing all farm operations for thirteen years. On legal documents that asked for his occupation, he sometimes wrote “farmer.” He even achieved fame for breeding a champion herd of milking Holstein Friesians, which won top awards from the dairy industry. He raised sheep and poultry, and his daughter remembered how he also loved his pigs.

Having full control to shape Winterthur to his liking, one of the first things du Pont altered was his father’s Pinetum. To the son, it felt like a collection of specimens arranged artificially, so he naturalized it with quince (Chaenomeles) planted along its broad path, creating his Quince Walk. He gave shrubs room to grow to their natural form. In his single-paragraph foreword for Hal Bruce’s 1968 book, Winterthur in Bloom, du Pont echoed Robinson and Sargent, writing, “I like to see the shape and size of big shrubs; even though they are always part of a group, one has to know when planting just how big and tall the shrubs are going to be.” Against the dark greens of the conifers he also planted Winterthur’s boldest flame azaleas (Rhododendron calendulaceum), which bloom in tangerine, apricot, salmon, and lemon yellow. Later, he added a dawn redwood (Metasequoia glyptostroboides) from the Arboretum.

Photo of azaleas blooming beneath conifer
“I like to see the shape and size of big shrubs,” du Pont would write. Here azalea masses drift beneath conifers at Winterthur Museum and Gardens. Carter Wilkie

Du Pont then enlarged the big house, which grew to 175 rooms, to accommodate his expanding collection of American antiques. According to his daughter, du Pont’s interest in early Americana was sparked by a visit to the Webb estate, in Shelburne, Vermont, in 1923, when he spotted pink Staffordshire china arrayed on a brown pine dresser. Those very pieces are now displayed among the ninety thousand objects of decorative art in Winterthur’s collection. A visit that same year to the Gloucester, Massachusetts, home of Henry Davis Sleeper (now owned by Historic New England) inspired du Pont to install period rooms lifted from colonial era houses, as Sleeper had done, and as Ben Perley Poore had done in a haphazard way before at his estate, Indian Hill, in nearby Newburyport.

Du Pont’s genius as a designer of naturalistic landscapes shows in the way he fit his mansion into the existing topography. He left the north elevation of the existing house at four stories, but on the opposite side, he tucked nine new stories into a steeply sloping hillside that absorbed the height and volume. He also sited the building and new entrances carefully within an envelope of mature oaks, beech, and poplars. The height of the trees, at 150 feet, made the mansion appear less large. From Robinson and Olmsted, he had learned to subordinate built structures to their natural surroundings.

As he expanded the house, du Pont hired his friend Marian Coffin to makeover the gardens along its southern shaded slope, which cradles a swimming pool and twin pool houses. The gardens Coffin designed were the most formal at Winterthur, arranged on straight axes punctuated at the ends by semicircles. Her talents complemented his. She architected the skeleton, and he fleshed it out. He outfitted the design with plants, softening her stonework and straight lines with shrubs and understory trees that he allowed to grow naturally, out over the edges. As collaborators, Coffin and du Pont would bounce ideas off one another throughout their lives. Du Pont wrote her playfully during their work on the project, “I am enclosing a copy of a letter from Mr. E. H. Wilson of the Arnold Arboretum in regard to the Picea asperata notabilis. This is the tree which you wished so ruthlessly to destroy.” Native to Sichuan, China, dragon spruce (Picea asperata var. notabilis) was described by Wilson and Arboretum taxonomist Alfred Rehder, in 1916, and is considered endangered today.

Du Pont weaved Coffin’s formal gardens into Winterthur’s naturalistic grounds by dissolving boundaries within the landscape. Like Olmsted’s design of the Arboretum, there are no obvious seams between garden areas at Winterthur, only gentle transitions. The edge of Azalea Woods dissolves into the meadow beyond it, with shrubs extending out from under trees like an irregular line of troops beginning their advance on an open field. Following Robinson’s dictate, Winterthur allows the lower limbs of trees to grow into the ground naturally, eschewing cuts in turf for neatly delineated beds where field and forest meet. Whereas du Pont’s cousin Pierre, at Longwood Gardens, had used princess trees (Paulownia tomentosa) to line a formal allée to the entrance of his monumental conservatories, H. F. du Pont inserted Paulownia into his woodland edge as a transition element, its lavender blossoms catching the eye and leading visitors to the next sequence of seasonal bloom. A large mound of saucer magnolia (Magnolia × soulangeana), planted by du Pont’s father in 1880, the year du Pont was born, carries the spring bloom into fields of grass, as do two large Sargent cherries (Prunus sargentii) beyond them, gifts to Winterthur from Sargent in 1918. Nearby, du Pont collaborated with Coffin again to create an April-blooming garden of fragrant ornamental trees and shrubs, many of which came from the Arboretum through its Cooperative Nurserymen program.

Planner for Posterity

In 1930, as du Pont’s sister, Louise, planned for the future of Eleutherian Mills, the family’s restored ancestral home, H. F. du Pont established a nonprofit entity charged with maintaining Winterthur in perpetuity as “a museum and arboretum for the education and enjoyment of the public.” The museum opened to the public in 1951, when du Pont relinquished responsibility for it to professional staff. He continued to oversee the gardens and farmland, calling himself head gardener.

As he grew older, du Pont became more impish in the garden. He relaxed his highbrow standards of what constituted good taste. Before mod fashion in the 1960s made pink and orange a popular color combination, he inserted salmon blooming azaleas as accents into his Azalea Woods and placed bold, red-blooming azaleas next to lavender ones to “chic it up,” in his words. Coffin praised what she called his “near discords” of color. Tossing aside rules he learned about cool, pastel subtlety from the teachings of Gertrude Jekyll, he installed a carnival of hot colors in his summer Quarry Garden using primroses (Primula). Gordon Tyrell, who worked closely with du Pont in the garden, confided in a colleague, “He was mixing colors. I know he did it intentionally, but they were beginning to yell. There were lavenders and mauves and reds. It wasn’t offensive, but I think it was a little joke of his really. And I said, ‘You can’t do this.’ And he said, ‘I’m doing it.’ And he did it.”

Although du Pont loosened Jekyll’s tether on color, the aging gardener remained devoted to William Robinson’s naturalistic aesthetic into the ninth and final decade of his life. When he hired architects to design a pavilion that became Winterthur’s visitor center, he told them, “Make it look like it isn’t there.” Tucked within his woodland, the modernist building is the color of bark, and its glass exterior walls reflect the foliage around it, camouflaging its mass. The approach road to the visitor center follows swales around hills, through open meadows. He had the road sunken below sightlines so as not to mar the views.

Photo of azaleas blooming around formal rectangular pool with mansion behind
In 1929, du Pont commissioned his friend Marian Coffin to redesign the south-facing slope below his mansion. Du Pont softened the formal lines with masses of shrubs. Carter Wilkie

Coffin liked to tell prospective clients that great gardens require three things: money, manure, and maintenance. Winterthur had all three in abundance. After du Pont’s death in 1969, his endowment supplied the money, but the manure had to come from elsewhere. His will stipulated that his livestock operations be liquidated upon his death, to focus resources on the museum. Because du Pont oversaw and financed the gardens until he died, it took the institution two decades to formalize a Garden Department to preserve his landscape design intent. By then, his naturalistic garden was overgrown. Three years were spent assessing what was there and culling what shouldn’t be, including forty truckloads of branches pruned from Azalea Woods. In the Pinetum, a mature Atlas cedar (Cedrus atlantica ‘Glauca’) was pruned at its base to reopen the circular seating area and sightlines around it. The spot reminds a visitor of the vantage point atop the Arboretum’s Bussey Hill Overlook, where puddingstone boulders in the ground encircle the base of a large eastern white pine (Pinus strobus) and Japanese white pines (Pinus parviflora). At Winterthur, Sargent’s role in shaping the Pinetum is memorialized on a plaque.

Decades before, when du Pont planted bulbs by the tens of thousands, he wrote to Coffin that no mere mortal could do what he wanted done at Winterthur. And he was right. What makes Winterthur unique in America is its scale—the product of vast wealth, space, and time. Few landscapes in the new world are the work of generations of a single family, let alone one man’s lifetime of eighty-nine years. Today, Winterthur fulfills Henry Francis du Pont’s wish “that the museum will be a continuing source of inspiration and education for all time, and that the gardens and grounds will of themselves be a country place museum where visitors may enjoy as I have, not only the flowers, trees and shrubs, but also the sunlit meadows, shady wood paths, and the peace and great calm of a country place which has been loved and taken care of for three generations.”


Bruce, H. 1968. Winterthur in Bloom: Winter, Spring, Summer, Autumn. New York: Chanticleer.

Cantor, J. 1997. Winterthur. New York: Harry N. Abrams.

Fleming, N. 1995. Money, Manure & Maintenance. Weston: Country Place Books.

Libby, V. 1984. Henry Francis du Pont and the Early Development of Winterthur Gardens, 1880–1927. Master’s Thesis for the Longwood Graduate Program in Public Horticulture, The University of Delaware.

Citation: Wilkie, C. 2020. Collector on a Grand Scale: The Horticultural Visions of Henry Francis du Pont. Arnoldia, 77(4): 12–23.

Lord, R. 1999. Henry F. du Pont and Winterthur: A Daughter’s Portrait. New Haven: Yale University Press.

Mangani, D., et al. 1995. The Winterthur Garden: Henry F. du Pont’s Romance with the Land. New York: Harry N. Abrams.

Robinson, W. 1870. The Wild Garden: Or, Our Groves and Shrubberies Made Beautiful By The Naturalization Of Hardy Exotic Plants. London: John Murray. (Also, an expanded edition with new chapters and photography by Rick Darke. 2009. The Wild Garden: Expanded Edition. London: Timber Press.)

Carter Wilkie grew up near Winterthur, where his mother took him on frequent visits and would quiz him to identify plants she had pointed out on previous walks. For thirty years, he has resided within a short walk of the Arboretum, where he can be spotted reading tags on trees. This article is based on a talk he gave to the local garden club in Roslindale in March 2018.

From “free” to “friend”…

Established in 1911 as the Bulletin of Popular Information, Arnoldia has long been a definitive forum for conversations about temperate woody plants and their landscapes. In 2022, we rolled out a new vision for the magazine as a vigorous forum for tales of plant exploration, behind-the-scenes glimpses of botanical research, and deep dives into the history of gardens, landscapes, and science. The new Arnoldia includes poetry, visual art, and literary essays, following the human imagination wherever it entangles with trees.

It takes resources to gather and nurture these new voices, and we depend on the support of our member-subscribers to make it possible. But membership means more: by becoming a member of the Arnold Arboretum, you help to keep our collection vibrant and our research and educational mission active. Through the pages of Arnoldia, you can take part in the life of this free-to-all landscape whether you live next door or an ocean away.

For more tree-entangled art, science, and writing, subscribe to Arnoldia by becoming a member of the Arnold Arboretum.