Longwood shows progress on $250 million revitalization project, set for fall 2024 opening

EDITOR'S NOTE: This story has been updated to clarify an aspect of the expansion that will house Roberto Burle Marx's design. 

A beehive of energy is swarming at the world-renowned horticultural center Longwood Gardens this season.

A small group of reporters saw worker bees in boots and hard hats swarming the site on Friday, Oct. 20, during a behind-the-scenes tour of the garden center's $250 million revitalization project: "Longwood Reimagined: A New Garden Experience."

The project opens to the public in fall 2024 and promises to reimagine 17 acres of the venue's Conservatory and land grounds.

The crown jewel and largest single piece of the project is the new West Conservatory. This 32,000-square-foot glasshouse, designed by Weiss/Manfredi, is now under glass with 1,958 glass panels installed, Longwood officials said.

The centerpiece includes pools, gardens and fountains designed by Reed Hilderbrand.

The separate Cascade Garden, designed by Weiss/Manfredi to house the revered Brazilian landscape architect Roberto Burle Marx’s only existing design in North America, is in the process of having 484 panels of glass installed.

“We are reimagining and rethinking what the garden under glass experience will be for the 21st century,” Paul B. Redman, president and CEO of Longwood Gardens, said in a statement. (Redman didn't attend the Oct. 20 media event due to illness.)

“These new glass palaces continue Longwood’s legacy of being one of the world’s innovators in conservatory design and leading patrons of garden and landscape design," Redman said.

Finding new ways to connect architecture with horticulture furthers the vision of Longwood founder Pierre S. du Pont, who built their first conservatory.

Du Pont opened Longwood to the public in 1921.  

Sustainability at Longwood

With a focus on sustainability, 130 geothermal wells have been drilled about 350 feet deep and are connected to a ground-source, multi-stage heat exchanger.

This offers heating and cooling to the administration building, lower reception suite and lower level of the new conservatory. The main level of the new conservatory relies on passive conditioning.

Longwood officials said 10 earth ducts provide year-round passive tempering of fresh air in the conservatory. The earth ducts are three-foot diameter tubes, 300 feet long, buried under the south slope of the gardens outside the conservatory.

Fresh air is drawn into the earth ducts near the Idea Garden.

As it is drawn through the earth ducts, air is warmed or cooled by the earth depending on the season. The earth-tempered air is introduced to the space at the pedestrian pathway to provide passive thermal comfort for occupants and visitors, Longwood officials said. 

The building uses all natural ventilation rather than relying on mechanical cooling during warm months.

Longwood went 'above and beyond' for accessibility

Michael Manfredi, co-founder of the architect firm Weiss/Manfredi with his wife Marion Weiss, said his firm "went above and beyond" to make sure Longwood Reimagined was accessible for visitors.  

While "buildings have really rigorous codes, in terms of accessibility," Manfredi said that's not the same for gardens, especially existing gardens. But for this Longwood project, Manfredi said it was important to make things like ramps more visible to guests.

"We tried to make sure that everybody can get the same experience. So, if you're in a wheelchair, you wouldn't feel like you'd have to [travel] half a mile," he said. 

Making progress on $250 million project

Other elements of the $250 million project that have progressed include the construction of a new education and administration building named The Grove.

The exterior of The Grove, a 46,000 square-foot facility, is complete and interior work has begun on the state-of-the-art library and classrooms, Longwood officials said.

Overlooking the Main Fountain Garden, the 1906 Restaurant and private event space named The Fountain Room, is receiving interior finishes including a molded design on the vaulted ceiling, officials added.

Longwood Reimagined employs repurposing

In terms of horticulture, custom soil mixes are being used for all areas of the project.

The majority of the 9,000 cubic yards saved from the restaurant excavation are being blended with compost on site and will be used in the Meadow landscape, Longwood officials said.

Inside the conservatory, Longwood horticulturists have developed a specialized blend of seven different components intended to support Mediterranean gardens.

"The remaining turf and garden areas within the 17 acres of landscape will receive sand-based, high-performance soils to provide well-draining media that will support plant growth," Longwood officials said.

Recently, Longwood planted 765 boxwood in front of the 1906 Restaurant and The Fountain Room as part of a 525-foot-long garden terrace adjoining the Main Fountain Garden.

Keeping Longwood 'relevant'

It'll be music to Longwood's ears when the Reimagined project is open. The maestro behind this botanical orchestra is Bancroft Construction in Wilmington.

Bancroft currently has 250 workers per day at Longwood for this project, Greg Sawka, president and CEO of Bancroft, told Delaware Online/The News Journal.

From electricians to carpenters, the Bancroft CEO said every trades-person is like a section or instrument that needs to work together to make beautiful music.

"We're the orchestra leader and you need the conductor. If everybody's on their own doing their thing with no conductor, then it sounds like bad music," said Sawka, who is pleased with the sound his group his been making thus far.

Patricia Evans, spokesperson for Longwood, said she’s looking forward to the debut of Longwood Reimagined, a project they’ve been planning for over a decade.

"It's really about making sure that we are remaining relevant and innovative for years to come," Evans said.

More Longwood Gardens stories

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Here are 5 tips: To make the most of your first visit to Longwood Gardens

This Delaware du Pont estate: It may be worth $50 million. Look who's buying it.

If you have an interesting story idea, email lifestyle reporter Andre Lamar at [email protected]. Consider signing up for his weekly newsletter, DO Delaware, at delawareonline.com/newsletters.

This article originally appeared on Delaware News Journal: Longwood Gardens shows progress towards 2024 'Reimagined' project