for immediate release

The Plant Science Center Gardens

Green Roof Garden and Rainwater Glen

Media Only:
Julie McCaffrey
(847) 835-8213
jmccaffrey@chicagobotanic.org

GLENCOE, Ill. (August 26, 2009) — When the Chicago Botanic Garden opens the new Daniel F. and
Ada L. Rice Plant Conservation Science Center to the public on September 23, 2009, it will also be adding a new display garden. The Plant Science Center Gardens will consist of a 16,000-square-foot Green Roof Garden atop the building and a Rainwater Glen that surrounds the building. The Plant Science Center Gardens will provide a beautiful space to contemplate all that plants provide us in our daily lives, and drive home the need to save the plants in order to save the planet. The view from the Green Roof Garden to the Evaluation Garden and adjacent Dixon Prairie and Evening Island will also be spectacular.

The Ellis Goodman Family Foundation Green Roof Garden South will be planted with North American native plants only. The Josephine P. & John J. Louis Foundation Green Roof Garden North will be planted with a mix of plants currently accepted as good green roof plants as well as exotic and native plants that have potential for green roof use. A total of 320 different plant taxa was selected by a team of Garden staff and the lead design firm, Oehme, van Sweden & Associates. The team looked at plants that have been successful in other green roof applications as well as regional and national native plants, but didn't want to rule out plants that showed potential. They selected plants that are sun-loving, drought tolerant, have a shallower root system and can withstand windy conditions. Plants will be planted while they are small in size so they to adapt to the growing conditions at an earlier growth stage. They will be watered and weeded, but no supplemental fertilizers or special winter protection will be provided. After the first two to three years, minimal maintenance will be provided.

A Unique Living Laboratory
Very few institutions conduct comparative trials of ornamental plants for landscape use, and fewer still conduct trials of plants for innovative rooftop gardening. The Green Roof Garden will allow scientists to determine which plants are best suited to growing in this extreme environment. The living laboratory will be outfitted with equipment to monitor soil moisture, wind and light levels, and temperatures inside the building and in the various layers of the plantings. Scientists will monitor plant health, aesthetics, and survivorship of plants and be able to recommend plants that are low-maintenance, absorb water and nutrients from rainfall (lessening runoff into storm sewers), and cool the building below (lessening energy use), while providing an aesthetic retreat. The trials will be among the most comprehensive rooftop plant evaluation program in the country and the results will be reported on the Garden's website.

The planting beds will be constructed of several layers, beginning with a waterproofing layer, two layers of hard foam insulation, a root barrier fabric, a drainage tile to allow water to drain away from the roots, a filter fabric to keep the growing media from clogging the drainage holes, and growing media as the top layer. The semi-intensive media is a gravel-like soilless mix formulated specifically for roof gardens. It is lighter weight and more porous than soil, allowing water to drain quickly, thus reducing the weight load on the roof.

Energy Efficiency Part of Design
The Green Roof Garden is designed to provide insulation that will cool the building in summer and keep it warmer in winter, decrease the "urban heat island" effect (increased temperatures due to heat retention of manmade surfaces), increase the roof's lifespan by shielding it from weather extremes, reduce stormwater runoff, remove carbon dioxide from air and pollutants from water, absorb sound and create habitat for animals such as insects and birds. The Rainwater Glen will collect water draining from nearby parking areas and the Green Roof Garden and filter it within the garden's plant community. The Plant Science Center Gardens ensure the building has a low environmental impact from top to bottom.

The Green Roof Garden will be accessible to the public during the regular business hours the Plant Science Center is open, providing an opportunity for visitors to watch the evaluation project progress in the coming years. Interpretive materials will explain how to create a green roof garden at home and explain the evaluation process.

The Rainwater Glen differs from a typical rain garden because in the Garden's exceedingly tight clay soils a traditional rain garden, where the water slowly percolates into the underlying soil, will not work. Instead, the Garden has intentionally built a moist-bottom swale where plants preferring consistent "wet feet" will reside. The Rainwater Glen will function like a river’s floodplain. It will hold back stormwater runoff, allowing deep-rooted native plants to facilitate absorption and help to filter impurities. The Rainwater Glen will contribute to improved water quality at the Garden and, importantly, in each of the ecosystems it will eventually flow through. The entrance to the Plant Science Center is defined by a 40-foot long gently sloping bridge over the Rainwater Glen, with benches and planters integrated into the bridge design.

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Editors, please note: The Chicago Botanic Garden's newsroom is online at www.chicagobotanic.org/pr. For digital images, contact Julie McCaffrey at (847) 835-8213 or at jmccaffrey@chicagobotanic.org.

The Chicago Botanic Garden, one of the treasures of the Forest Preserve District of Cook County, is a 385-acre living plant museum featuring 23 distinct display gardens surrounded by lakes, as well as a prairie and woodlands. With events, programs and activities for all ages, the Garden is open every day of the year. Admission is free; select event fees apply. Parking is $20 per car; free for Garden members. The Garden is located at 1000 Lake Cook Road in Glencoe, Ill. Visit www.chicagobotanic.org, or call (847) 835-5440 for seasonal hours, images of the Garden and commuter transportation information.

The Chicago Botanic Garden is managed by the Chicago Horticultural Society. It opened to the public in 1972 and is home to the Joseph Regenstein, Jr. School of the Chicago Botanic Garden, offering a broad array of adult classes in plant science, landscape design and gardening arts. Through the Division of Plant Science and Conservation, Garden scientists work on plant conservation, research and environmental initiatives that have global impact. The Center for Teaching and Learning brings the wonder of nature and plants to children, teens and teachers. The Garden's Horticultural Therapy and Community Gardening programs provide nationally recognized community outreach and service programs. A program of the Chicago Botanic Garden, Windy City Harvest is an organic vegetable and plant production enterprise that provides instruction in sustainable horticulture and urban agriculture to residents of Chicago’s North Lawndale and West Side neighborhoods.

The Chicago Botanic Garden is accredited by the American Association of Museums and is a member of the American Public Gardens Association (APGA). The Chicago Botanic Garden is also host to Botanic Gardens Conservation International-U.S., and a member of the Center for Plant Conservation. In 2006, the Chicago Botanic Garden received the Award for Garden Excellence, given yearly by the APGA and Horticulture magazine to a public garden that exemplifies the highest standards of horticultural practices and has shown a commitment to supporting and demonstrating best gardening practices.