HMWhite’s roof garden holds its own among the landmarks at Rockefeller Center.

By Margaret Shakespeare

In the first half of the 20th century, Rockefeller Center set new urban design standards. Its features have become New York City cultural fixtures: the Rainbow Room, the Channel Gardens, and the grand promenade leading to the massive, gilded Prometheus statue hovering above the sunken ice rink. From the outset, the landscape elevated the street experience, and occupants in the office towers above benefited from building setbacks with exquisitely groomed terrace parterres overlooking Fifth Avenue.

Plans for further rooftop development, including parks and traditional parterre gardens, boxwood-framed annual flower beds, and a series of sky bridges, remained unfulfilled—until the real estate behemoth Tishman Speyer took ownership and active management of the 19-building, 22-acre Rockefeller Center in 2001, making renovations and structural upgrades before focusing on amenities for office tenants. At Radio City Music Hall, nine stories above the eye-high-kicking Rockettes, a dingy brown half acre of roof lay empty, except for three pavilions housing pulleys and mechanisms to operate Radio City theater curtains, scrims, and other stage equipment.

Hank White, FASLA, the founding principal of HMWhite, had been working on a new residential project at a Tishman Speyer property elsewhere in New York when Chris McCartin, a managing director at the company, asked for a landscape proposal for Radio City’s rooftop to complement the adjacent interior tenant amenities area. “The expectation was to have an equivalent design distinction to the Channel Gardens,” White says. He immediately wanted to create a space with an aura of mystery and celebrate the beauty and symmetry of the canyon of surrounding buildings. “It took 15, 20 minutes to devise a plan that was all about procession, coming into a contained space,” White says. “And then—during COVID-19—we had contract drawings by January 2021, construction started in late April 2021, and we had it done in seven weeks. It was an economics-driven rush deadline.”

White applied 21st-century concepts and technological advances—maximizing the number of trees by coordinating their location with the roof’s structural beam grid; coordinating a layered subsurface geofoam topography with deeper growing medium zones for each tree; using lightweight, non-settling growing medium—to realize Radio Park. He steered slyly away from the axial orientation of the historic gardens (some of which can be glimpsed on terraces down the West 50th Street block). From the indoor amenity area, the pavilions, clad in copper doors enriched with a blue patina, form the park entry and set a contemplative mood. Gentle dips and curves of a pathway ahead invite exploring. Revelation of plantings, colors, textures, sounds, movement, and spatial context all come gradually.

“Memorable landscape experience is all about first impression,” says White, who conceived the park in three parts: an 87-tree birch forest as a “spatial wrap”; a Yoshino cherry grove with “all white-flowering plants blossoming at different times”; and the Belvedere, a stern row of European hornbeams across the western edge of the rooftop. “We worked with structural engineers to create the topography and used the roof’s functional organization through a space-making topographic structure,” White says. Building vents and other hardware stayed put, but with planting beds cleverly blended in, along with benches constructed of splashy Alaskan yellow cedar. Three bench tiers overlook a lawn and dense patch of regularly pruned boxwoods. Tree root balls required 30 inches of growing medium, all the better to give surface undulation to the otherwise flat roof.

“By blanketing roofs with thermal insulating landscapes, buildings will benefit from significant energy conservation costs and extended roof waterproofing life cycles,” White says.

Without apology, this small-but-mighty plot of nature is juxtaposed with the massive built environment in which it sits. “The sound of leaves mitigates the sounds of the city,” White says. “And one [can contemplate] the mysterious juncture of landscape and building. Organic against man-made actually brings us closer to nature. These types of spaces and accessibility are vital to the urban living condition.”

White says that once the last trowel tucked the last plant into earth, birds and butterflies discovered this new skyward patch “within minutes” and flittered into Radio Park, with all the natural grace and belonging of the dancers downstairs.