KENNET SQUARE, PA.- Longwood Gardens’ new East Conservatory Plaza, featuring the first terraced lawn in the United States designed by landscape architect Kim Wilkie and the largest indoor green wall in North America, will open to the public on October 9, 2010. The dynamic new gathering space and venue for educational talks, horticultural demonstrations and special events continues Longwood founder Pierre S. du Pont’s legacy of creating unique spaces that integrate into the natural landscape.

The East Conservatory Plaza is composed of five tiers of sweeping grass-covered terraces that emerge like steps from the landform. The Plaza is surrounded by woodland plantings, including a more than 200-year-old English Yew. The innovative design of the terraced lawn creates a sculptural clearing, allowing for dramatic views of the Topiary and other gardens to the south, as well as of the East Conservatory façade.

“Kim Wilkie’s unprecedented design for the East Conservatory Plaza is deeply rooted in tradition, while also embracing innovative landscape design, which captures the very essence of Longwood Gardens,” said Director Paul Redman. “The plaza – both as a place of quiet contemplation and a site for creative programming – will engage our guests in new and exciting ways, advancing our mission to expand upon what a public garden is and what it offers to the public.” said Redman.

To mark the opening, the East Conservatory Plaza will feature special events and tours highlighting the environmental aspects of the project from 11 am to 4 pm on Saturday, October 9.

The East Conservatory Plaza has been integrated into the landscape by the careful placement of red maple, sweet-gum, bald-cypress, eastern red-cedar, tulip-tree, as well as southern bush-honeysuckle, Japanese holly, Virginia sweetspire and other shrubs, all of which are intended to enhance and extend the plantings of the surrounding landscape.

The composition of the sod in the Plaza is a special formulation created by Longwood Gardens. It includes a mix of two varieties of Kentucky bluegrass and three varieties of Tall fescue. The blend was selected for its early green color and resistance to disease. Currently, 65,000 square feet of sod is being grown for Longwood at Tuckahoe Turf Farm in NJ.

Due to the slope of the terraced landform, Longwood is using a novel and innovative combination of overhead and subsurface irrigation systems to provide adequate and efficient hydration. An overhead system alone would not suffice because of the potential for water to run off the slope; the subsurface irrigation system, which lies just below the surface, combats the runoff and supplements irrigation.

A unique feature of the Plaza is an unprecedented new concept of domed, naturally lit lavatory cabinets hidden within the landform. While examples of top-lit domes exist, particularly in Islamic architecture, underground domed cabinets such as these have never before been used for contemporary lavatories. The innovative design of the underground restrooms will take advantage of earth insulation, an age-old concept that is highly energy efficient and joins other existing environmental practices at Longwood. A curving glass-roofed corridor spine running between the two rows of lavatory domes is surrounded by a massive “living” or green wall, which will be the largest indoor living wall of its kind in North America.

Longwood’s new vertical garden features a panel wall system to support more than 47,000 plants and encompasses a surface area of 3,590 square feet — making it more than 50% larger than the current largest indoor green wall in North America at PNC Bank in Pittsburgh. The majority of the 25 species of plants featured in Longwood’s living wall are fern varieties including the evergreen Holly Fern, the versatile and showy Rabbit’s Foot Fern, the Button Fern, the Asparagus Fern with its feathery arching stems, and the delicate and lacy Maidenhair Fern, among others.

“The history of Longwood Gardens, from Pierre du Pont’s founding vision to the Garden’s commitment to environmental stewardship, education and the arts, very much informed and inspired the design for the East Conservatory Plaza,” said Kim Wilkie. “I wanted to create a gentle environment of light and shade that would be transformed by the changing hours of the day, a place where people could relax in the morning sunshine, enjoy views out onto the rest of the Gardens, take in a special event, or perhaps even attend a sparkling party at night.”

The East Conservatory Plaza is designed by Kim Wilkie, in collaboration with building architects Michaelis Boyd and local project landscape architects Wells Appel.