Chicago Botanic Garden
Project: Daniel F. and Ada L. Rice Plant Conservation Science Center, 16,000 square foot green roof
Client: Chicago Botanic Garden (Award Winner)
Landscape Architects: Oehme, van Sweden and Associates
Architects: Boothe Hansen Architects
Landscape Contractor: Sexton’s Landscape Concepts
Growing Media: Midwest Trading
Drainage System: J-DRain
Irrigation System: Becmar Sprinkler Systems
Waterproofing Membrane: Sika Sarnafil
“The Chicago Botanic Garden’s green roof is unique because it contains both evaluation areas and display gardens
and is open to the Garden’s nearly one million annual visitors.”
- Kris Jarantoski, Executive Vice President and Director
The Chicago Botanic Gardens, with over 958,000 annual visitors, are one of the most visited public gardens in North America. The green roof on the Botanic Gardens’ Rice Plant Conservation Science Center serves as both a scientific resource and a display garden for these visitors. While keeping with the highest aesthetic standard expected at the Chicago Botanic Gardens, the Center also evaluates a broad range of plants on their performance. The aim is to help expand the plant palette of Chicago-area green roofs. Three weather monitors measuring wind speed, velocity and direction, light intensity, humidity, air temperature, soil media moisture content, heat flux from the building and rainfall aid these efforts.
The 8,000 square foot north roof contains alpine and rock garden plants, cultivars and bulbs from around the world. The equally sized south roof contains native species. Combined, the roofs hold over 300 different taxa at planting depths of four, six, and eight inches. A permanent irrigation system is installed, but since establishment the entire roof has only required it twice.
The green roof provides a special resource for the graduate program in Plant Biology and Conservation that is offered in collaboration with Northwestern University. There is also an ant diversity study being conducted; and data being collected concerning pollinators on green roofs and media properties for a doctoral program. On a daily basis, students from area high schools and colleges visit the roof as part of biology, conservation, horticulture and design programs. Interpretive panels along the roof's railings discuss the environmental benefits of green roofs and explain the layers of a green roof. The spacious viewing decks provide gathering space for classes and other groups, and allow a complete view of the roof.
The green roof is only one of the building’s many sustainable design components. For most rainfall events, 100% of the green roof’s runoff is retained by the rainwater glen that surrounds the building. 288 photovoltaic panels line the green roof and supplement the building’s energy needs. Harvested herbs and vegetables are grown in eight containers on the roof.
With handicapped accessibility and public hours every day of the week, the green roof at the Rice Plant Conservation Science Center is not only ensuring that a green roof-championing city is provided with the most updated plant data, but that all of the city’s residents can enjoy a beautiful sky-level garden.