Trees selected for WTC memorial represent areas impacted by 9/11.

The World Trade Center Memorial Foundation selected and began moving 18 oak trees from the Capital region so that they may become part of the Memorial honoring those who died in the attacks of September 11, 2001 and February 26, 1993.

The Swamp White Oak trees come from El Hannon Nursery, Inc. in Petersburg, NY and will be moved by the tree transplanting company, Environmental Design, to a holding yard in New Jersey where they will be maintained until their installation at the WTC site.

Trees are being selected from nurseries representing the following regions: New York, Pennsylvania, and the Washington, DC area in order to symbolize the areas impacted on 9/11.

"The selection and movement of these trees marks another step forward in realizing a lasting tribute at the World Trade Center site," Mayor Bloomberg said. "The Capital region trees will join the hundreds of other trees coming from areas in Pennsylvania and Washington, DC, in creating a sense of hope and renewal at the Memorial. Over the next couple years, the trees will be carefully nurtured until they are planted on the Memorial Plaza. Once the Memorial opens, the grove of trees will create new green space for visitors, residents, and workers to enjoy, while also providing a special place of remembrance."

Last fall the Foundation identified a total of 386 trees, including overstock, for the Memorial. The selected trees were fertilized and pruned and are now being dug and transported to a 20-acre holding site at Halka Nurseries in New Jersey where they will be boxed. At the holding yard, the trees will be continuously monitored, irrigated, and fertilized, and are expected to grow to 25 feet by the time they are transported and installed on the Plaza.

The trees must be moved to a holding site within 50 miles of Lower Manhattan in order to acclimatize the trees in a climate that resembles the WTC site. The trees will grow accustomed to the micro-climate conditions of the area. During this holding time, weak trees will be culled from the group and the trees will be pruned, fertilized, watered, and protected against pests. Environmental Design, which is working with the Foundation on the tree transplanting, was founded in 1977 by Tom Cox and is a world premier large tree transplanting company.

The company has led the drive to apply technology to tree transplanting, including designing and patenting the world's largest on-site hydraulic tree spade.

Environmental Design Owner and Founder Tom Cox said, "I consider this project the highlight of decades of work in this industry.

"As difficult as the logistics may be, everyone involved in the project, from the nurseries to the vendors, goes out of their way to work together. It's an honor to be a small part of building the World Trade Center Memorial."

Memorial landscape architect Peter Walker said Swamp White Oaks and Sweet Gums were chosen for their health and durability but also becuase they are "graceful and hopeful symbols of life and longevity."

In September 2005, the first trees for the Memorial Plaza were tagged in Eastport, New York and paid for through a grant from the United States Department of Agriculture Living Memorials Project. In April 2007, 31 Sweet Gum trees from Maryland were dug and transferred to the holding facility. These trees were supplied by the Maryland Highway Administration.