Kiley Garden

In 1988, landscape architect Daniel Urban Kiley and architect Harry C. Wolf completed the design of a rooftop garden for the new regional headquarters of the North Carolina National Bank (NCNB). While little of the original garden remains, the design is regarded as one of the most important modernist collaborations between a landscape architect and an architect. Wolf selected a site in downtown Tampa that was occupied by a public rose garden and parking structure, and NCNB convinced city officials to sell the property to the company, which planned to build what CEO Hugh McColl called the “finest banking hall in Florida” with a new rooftop garden as a public amenity. The 3.5-acre rooftop garden sat atop a parking garage and was integrated with Wolf’s cylindrical, 33-story office tower and 7-story cubical banking hall overlooking the Hillsborough River.

The entire 4.5 site was subjected to Wolf’s patterning system, wherein the geometry of the building, fenestration, and interior space is based upon the mathematical proportioning system of the Fibonacci sequence. Interior and exterior dimensions and the frequency of window openings conform to the mathematical series in which each number is the sum of the previous two prime numbers. Kiley collaborated with Wolf to incorporate that same proportional system in the design of the garden, resulting in a mathematical synthesis of vertical and horizontal elements in a powerful and cohesive design of the building and landscape. The design extended the carefully designed geometric proportioning system of the building complex into an intricate pattern of trees, palms, turfgrass, stone and concrete paving, fountains, pools, and runnels of the rooftop garden. It is a form of almost pure geometry that also draws in the surrounding street grid of the city. The result won international acclaim before its early demise.

Pedestrians entered the plaza from North Ashley Drive, walking up a short flight of steps to an arrival terrace eight feet above street level before ascending further to the rooftop garden above the two-level parking garage. The lower arrival terrace featured a segmented 78 x 39–foot reflecting pool set flush to the pavement. Planters in the pool featured large, live oak trees (Quercus virginiana) underplanted with a low shrub mass of dwarf yaupon holly (Ilex vomitoria “Nana”). The still water mirrored the glass cube of the cubical banking hall.

The roof garden was divided into east-west rectangular grass panels each 78 feet wide in varying lengths, with 13-foot-wide paved pathways between each panel. Reflecting the mathematical proportions of the office tower, the rows of palm trees were spaced on the 78-foot radius of the cylindrical tower, and the 13-foot-wide walkways were the same ceiling height as the interior rooms in the tower. The pavement and grass checkerboard pattern of the rooftop garden was more than eye-catching: it extended the geometry of the building complex to compositions found in nature, such as the organic patterns of pine cones and seashells. An elegant water garden comprising a reflecting pool and long stone runnels circulated water to low, circular fountains that animated the space with movement and quieted noise from the street.

The garden resembled a tapestry designed with the seventeenth-century influences of André Le Nôtre and Moorish paradise gardens of trickling water, like Spain’s Alhambra. Reflecting pools and paving patterns mirrored the vertical planes of the building complex. Forming allées lining the paths were 135 cabbage palms (Sabal palmetto). Eight hundred purple and white flowering crape myrtle trees (Lagerstroemia indica) appeared as if they were randomly planted within the grid, and the turfgrass planted between the checkerboard pavers softened and blurred the walkway-lawn edges.

At street level, park visitors saw only the long, lower terrace of the wedge-shaped roof garden, divided by the 400-foot-long, glass-bottom water canal that flowed with splashing water and passed dappled light into the garage and onto the paving below through a translucent glass bottom. The garage rooftop was designed like a private garden refuge. Its entrance was framed, ceremonially, by long ramps. On its far side along the river, an amphitheater provided a contemplative space to watch the sun set behind the onion-domed towers of the historic Plant Hotel on the campus of the University of Tampa.

Less than a year after the garden’s 1988 opening, water began leaking into the parking garage below, requiring the pools to be rebuilt. By the early 1990s water damage to the parking structure was apparent. A 1999 engineering report estimated that repairs would cost $2.5 million. By 2000, the leakage was so troublesome that the runnels, fountains, reflecting pools, and water gardens were abandoned. The city, struggling to maintain the deteriorating garden, considered demolition.

Maintenance essentially ceased and the garden became overgrown with weeds. Paving cracked and shifted hazardously. The rooftop garden was a modern masterpiece in ruin, an urban blight slated for redevelopment. In 2005, it was included on the Florida Trust for Historic Preservation’s Most Endangered Historic Places list, which brought the attention of Kiley admirers from around the world, who advocated for preservation. In 2006, hundreds of the crape myrtle trees were removed and in 2007–2010 the garage was repaired. The rooftop was partially rehabilitated using Kiley’s original drawings archived at Harvard University.

NCNB Plaza is among Kiley’s most iconic designs and is an exceptionally important work of modern landscape architecture. Nevertheless, the future of the rooftop garden is uncertain, as the garden today is nearly barren—a sun-blasted, flat checkerboard of concrete, limestone, and turfgrass. Gone are the primary allées of cabbage palms and groves of crape myrtle trees; the white and pink flowers no longer provide splashes of color, except for a clump surviving on the southwestern corner. A small section of the canal still exists between the cube and cylindrical tower. The reflecting pools on the lower terrace have been removed and paved over for vehicular drop-off and turn-around.

Critics claimed the plaza was impractical, too expensive to maintain, and rarely used. Others advocate for a full restoration that would return the partially rehabilitated checkerboard of grass and pavers to its condition on opening day, when it was clear that Kiley had created a modernist masterwork of urban park design.