Paul Cowie To Lead Talk In Quogue On 9/11 Memorial Trees

Paul Cowie was approached 13 years ago by landscape architect Peter Walker to tap his expertise as a New Jersey arborist and urban forester. Mr. Walker’s firm, PWP Landscape Architecture, is out of Berkeley, California—and Mr. Cowie said it’s no surprise they’d seek a local firm for consultation because “what works in California, won’t work in New York” as far as climate and environment.

However, Mr. Cowie was taken aback by the project: installing hundreds of trees to memorialize the lives of the 2,606 people who died when two hijacked airplanes struck the World Trade Center on September 11, 2001. Today, the National September 11 Memorial trees at Ground Zero are erected around two large fountain “voids” where the towers once stood.

“When we first got the call in 2005, it sounded like a big deal,” Mr. Cowie said in a recent interview. “It was only four years out from the tragedy and fresh in our minds. My ego ballooned to be asked to be a part of something so incredible, but eventually it popped and I broke out in cold sweats. It needed to be perfect, planting 400-plus trees with the whole city, the whole world watching.”

Mr. Cowie will be the speaker at an event hosted by the Westhampton Garden Club at 1 p.m. on Monday, September 24, at Quogue Community Hall to discuss his six-year role in this “nail biting” project that took a decade to complete. The opening of the group’s National Garden Clubs Flower Show will follow the presentation at the Quogue Fire Department.

“All of us have known someone, or knew someone, who was impacted by this attack on our country,” said Westhampton Garden Club President Inger Mejean. “The trees make—what is otherwise a very bleak, black and gray plaza—it beautiful with color in the fall. The area just comes to life—it’s triumphant, like we can handle anything.”

In 2003, Mr. Walker and architect Michael Arad were selected by a jury composed of artists, scholars, dignitaries and relatives of those who died in the 2001 attacks. What ensued was one of the “most complex construction projects in recent history in New York,” Mr. Cowie said.

In the first few years after PWP Landscape Architecture was selected for the project, the Ground Zero memorial was in the headlines for supposed delays. In actuality, Mr. Cowie said, engineers were hard at work below the plaza in the seven stories of subway lines and substructure under Fulton and Greenwich streets.

Also, much of the planning for the trees was happening off-site at a temporary nursery in New Jersey. Crews had selected and harvested hundreds of swamp white oak trees within a 500-mile radius of Ground Zero, and planted them in boxes by 2007.

“Those were the most studied trees that ever got planted,” Mr. Cowie chuckled. Typically, tree planting has a 10 percent mortality rate, he added.

“But we couldn’t chance it—they had to be perfect,” he continued. “When you dig a tree out of the ground, you’ve nearly killed it. When you plant it, it takes work to pamper it back to life.”

The first tree wasn’t planted at Ground Zero until 2010, hoisted in by crane on a busy Manhattan street. Mr. Cowie said the optimal time to plant was after the winter thaw but before the leaves filled out. The planting of the first 16 was that August, “the worst time to do it,” he added.

The plaza was ready with an advanced watering system. The plantings needed to be done before September, Mr. Cowie said. In fall, the leaves turn from a vibrant amber to a more subtle golden brown. In the right conditions, they even turn a pink color in their sometimes 60-foot-tall canopies.

There’s about 450 trees planted. Mr. Cowie said it would have been a “bad idea” if they were to memorialize a tree per person—trees eventually die, after all.

“It’s a rebirth bringing life back to a site where so much life was lost,” Mr. Cowie said.

Instead, the names are around the bronze rims of the pooling voids in the World Trade Center’s Twin Towers footprint.

“It gives me goosebumps just thinking about it,” Ms. Mejean said. “It’s something that all Americans should just see.”