“You had to explain the garden, rather than let it speak for itself,” says Mark Wilson, curator of collections for the West region of The Trustees of Reservations, the 125-year-old nonprofit that owns Naumkeag. “Half the design was gone.”

Naumkeag was already mature when its owner, Mabel Choate, left the visionary 48-acre property to The Trustees upon her death in 1958. The bequest came with an endowment, but it didn’t keep up with the maintenance or preservation demands of Steele’s quirky design. The Trustees did what they could, replacing dying birches and arborvitae while acknowledging that Naumkeag’s landscape was aging naturally, if not gracefully. Still, Wilson wished they could do more.

In the fall of 2012, he got his wish. The Trustees, the world’s oldest regional land trust, received an anonymous $1 million donation to restore Steele’s entire design. There were two caveats: They would have to raise another $1 million, and all the work must be completed by the summer of 2016, a tight schedule for a project that could easily take a decade. The clock began ticking that fall.

“It was a shock,” says Lucinda Brockway, The Trustees’ program director for cultural resources, of the rushed time frame. “It is not the way you want to work.”

But The Trustees, which runs 114 other scenic and cultural properties in Massachusetts, agreed that the opportunity was too good to pass up. After a few months of intensive planning, Brockway and Wilson stood in the garden as Naumkeag, a National Historic Landmark, began its radical transformation.

Mabel Choate met Fletcher Steele at a Lenox Garden Club gathering in the summer of 1926. Steele, a dapper dresser and bon vivant, was the best-known and the most forward-thinking landscape architect in America. Choate, then 55 and a seasoned world traveler, would soon inherit her family’s wealth and their Stockbridge summer homestead. Her father, Joseph Choate, a prominent New York City lawyer and ambassador to the United Kingdom, had paid nearly $36,000 in 1884 for the hillside property with mountain views. He hired his architect friend Charles McKim of McKim, Mead & White to design and build the family a 44-room, Shingle-style “cottage” atop the slope. He then hired Nathan Barrett—a self-taught landscape architect best known for designing all the streets and parks for the railroad town of Pullman, Illinois—who surrounded the house with formal Victorian gardens featuring linear pathways and tidy topiaries.

Barrett’s designs covered 8 acres of Naumkeag. After Choate and Steele began working together, they experimented with groundcover plants to replace many of the estate’s grassy expanses. Steele went on to build his designs in those areas, starting with an outdoor room, which would eventually become the Afternoon Garden. As a designer, Steele had one foot in the past and one in the future. He favored modern features such as sweeping, undulating lines and strong color, but believed a garden, even a new one, should never look up-to-date, that the design should have a patina about it. He also wasn’t afraid to overdo it, as he made clear with the Afternoon Garden’s intricate parterre, fountains, grape arbor, brightly painted Venetian ironwork benches, and great pots of fuchsias. Steele framed the whole shebang with merry gondola poles. Choate called the busy garden her “joy and delight.”

That garden began a nearly 30-year collaboration between two like minds, which in the end produced a series of gardens filled with movement, color, and whimsy. Steele reshaped the south lawn into a flowing curve that echoed the mountain ridge in the distance. He created terraces for Choate’s oriental tree peonies. He planted red, orange, and yellow roses atop snaking lines of pink gravel. When Choate asked Steele for a new staircase down to her cutting garden, Steele answered with the dramatic Blue Steps, which cascade through birches and yews like a spring waterfall.

“He thought of a garden as fine art, as a kind of stage for theater where a lot of our life is played out,” Brockway says. “I feel like at Naumkeag he took that to the highest level.”

What The Trustees lacked in time they made up for in documents. Steele, a meticulous record-keeper, wrote copious notes and made thorough lists of the plants he used at Naumkeag. Early on in the restoration, a researcher combed through those records and made a planting key for every garden. The fast-paced project was divided into five phases and plotted on a spreadsheet. But a garden restoration looks far tidier on paper than it does in practice.

That first spring, Wilson and his crew cut down a small forest of hemlocks, spruce trees, and Norway maples, and dug two trenches for 70 linden trees. The cranes and tree grinders roared so loudly, Wilson says, people could hear them almost a mile away in quaint downtown Stockbridge. Then it rained for a month. The trench filled with water, and the open hill became slick with mud.

Brockway sighs when asked about the first phase of the restoration. Wilson says he has blocked it out. The Trustees, eager to show rapid progress, restored five of Naumkeag’s gardens in about three months of 14-hour days. Despite Steele’s vast array of notes and photographs, the records only took them so far. While cleaning up a pile of debris, the crew accidentally pulled up the sod underneath and unearthed a small rock garden that had gone missing for decades. And to set the bend in a curving line of cedar posts, Wilson and Brockway stood on the patio and looked to the silhouette of Bear Mountain to the south, just as Steele and Choate would have. “We had to learn to think like them,” Wilson says.

They also had to improve on what Choate and Steele had created. Parts of the garden did not survive the years, so the crew strengthened the stonework and sunk the cedar posts deeper into the earth. They installed about a mile’s worth of water lines and fixed the fountains, which often went dry.

The half-moon-shaped fountains built into the Blue Steps not only sputtered, but were also the wrong color. For years they had been repainted robin’s egg blue, but Steele, as his records made clear, had used a deep navy—a dramatic difference. “Every year that we matched that color it must have gotten a little lighter blue,” Brockway says. “A lot of people go into restoration projects assuming they know what it should look like without checking records. Passion for accuracy is what makes for a good restoration.”

By July 2013 the first phase of the project, including the Blue Steps, was complete. The Cultural Landscape Foundation (TCLF), a nonprofit that promotes appreciation of landscape architecture and design, offered a tour for 50 people that fall. Some 200 showed up. Charles Birnbaum, TCLF president and founder, watched as visitors paraded up and down the steps. What was once mostly a pilgrimage site for designers had clearly captured the popular imagination. “We’ve seen a major shift in the public about the value of landscape and landscape architecture as a heritage resource,” he says.

Naumkeag’s renaissance, Birnbaum adds, is one example of how landscape design’s historic and cultural importance is, at last, on the rise. A broader sign is the still small but growing number of National Historic Landmarks named as such because of the importance of their landscapes. When Naumkeag was added to the National Register of Historic Places in 1975, it was because of the McKim, Mead & White house. But when it became an NHL in 2007, Steele’s landscape design was also cited.

Robert Page, director of the Olmsted Center for Landscape Preservation at the National Park Service, says the idea of what makes for a culturally important landscape is also changing for the better. He points to the planned resurrection of a 2-acre vegetable garden at the Home of Franklin D. Roosevelt National Historic Site in Hyde Park, New York, and a plan to restore the views along the roads in Acadia National Park. “Things are happening in parks and gardens that [would have] seemed really grand a while ago.”

Brockway, on the other hand, feels the preservation of landscape design still lags too far behind that of historic building restoration—in part, she says, because the needs of landscape restoration are so different. Landscapes, compared to buildings, are made of living, dynamic materials that grow and die. Unlike buildings, gardens and landscapes are meant to change and age, but only to a certain point. That point isn’t always easy to divine until it has passed.

Landscape restorations also must consider climate change, pests, invasive species, and shifting topography. They can require cutting down trees—sometimes lots of them, which can upset people. At Naumkeag, 200 trees were dug up as part of the restoration. Yet 250 were planted to bring back Steele’s design.

By the spring of 2015, Wilson could show off a mostly reinvigorated garden, a project that ultimately cost $3 million. He led a visitor along the gravel path of the linden allée, down the famous Blue Steps, past the cutting garden with its delphiniums, daylilies, and peonies, past the blooming rose garden, and through the brick entrance to the Chinese Garden, which was still in the works. Stumps and roots stuck out of a sea of mud. A table stood on its side. Wilson pointed to one particularly mucky corner. “Careful. I lost a shoe over there.”

The Chinese Garden took 20 years to complete. Steele went to China in 1933 and came back with a trove of design ideas, while Choate went in 1935 and came back with a trove of antiques. In 1936 they began to put the two together. Steele used many of the elements of a classic Chinese garden: a temple with a blue-tiled roof, moving water, and the circle-shaped exit of the moon gate, which is believed to bring good luck as you step through it. He added a patina by whitewashing the redbrick walls. Still, his garden has an undeniable American touch. Unlike a traditional Chinese garden, which looks inward, Steele’s looks outward. Standing atop the temple platform, you gaze across the cow pastures below to the forests and mountain ridges in the distance, an expansive view that is more inspiring than meditative.

By the fall of 2015, the sea of mud was replaced with ginkgos and working fountains. Water slipped down two runnels. When a double hemlock hedge is replanted along the driveway this spring, The Trustees will have met their deadline.

More work lies ahead. A fifth phase will return Naumkeag to the working farm it once was. The apple and pear orchard was already rejuvenated in 2014, and the greenhouse, which collapsed under heavy snow in 1972, will be replaced and used to cultivate and overwinter plants for the formal gardens.

Ongoing maintenance work began before the restoration was completed. The crew has already pruned boxwoods, installed a new water pump, and replaced some trees. Having successfully brought Naumkeag back to its full glory, The Trustees now face the even bigger challenge of keeping it that way.