By Paulina Firozi Chicago Tribune.
For more than a decade, Chicago has been at the forefront of the green-roof movement. Now the city is poised to take an active role in the next environmental push, using roofs to grow food. It's a movement that is sparking interest in cities nationwide.
Rooftop farms are popping up around the city, from the McCormick Place convention center, which has grown tens of thousands of pounds of produce since 2013, to a historic Pullman neiborhood factory, expected to have the world's largest operation when it's completed this summer, to small businesses and educational programs.
Steven Peck, founder and president of Green Roofs for Healthy Cities, a Toronto-based industry association that promotes green roofs, said cities have "just scratched the surface" in the conversation about green roofs and rooftop farms, which are "making use of an otherwise wasted space."
Across the country, there has been a call for new food-producing spaces, Peck said.
"There's a demand for high-quality food in our cities, a consumer demand for it, a social need for it," he said. "There's a longing for people living in densely developed cities to reconnect to farming and to nature, to rooftop agriculture."
It's too early to tell what kind of impact rooftop farming, now only in its infancy, could have on food production.
There are at least 13 rooftop farms in Chicago, said Peter Strazzabosco, deputy commissioner of the Chicago Department of Planning and Development, although he said there could be more.
Other cities noted for green development include Washington, with three rooftop farms, and Toronto with two, according to officials in those cities.
Michael Bryson, a professor of humanities and director of sustainability studies at Roosevelt University, said the discussion of sustainability is crucial and that urban agriculture can contribute to the evolution of how food is grown and distributed.
"It's super important, recognizing that something as basic as where and how we grow our food has reverberations in other systems: in transportation, in energy, in waste management, in mitigating pollution from the trains and trucks that transport our food," he said.
And rooftop farms make sense in Chicago, a city known for green development, Bryson said.
"Chicago has really embraced the ethos and practice of urban farming," he said, "taking vacant land and repurposing it and reclaiming it to impact food deserts, to grow fresh food that is affordable and accessible."
After a trip to Germany, former Mayor Richard M. Daley returned with a mission to turn Chicago into a green-movement leader and installed the city's first green roof atop City Hall in 2000.
In the years since, green roofs have gotten a lot of attention, and Chicago has been recognized as one of the leaders in North America. The city has more than 5.5 million square feet on more than 500 rooftops, Strazzabosco said.
But even that is still a small number. Those 500 green roofs represent a little less than one-tenth of 1 percent of Chicago's more than half a million buildings. In Germany, experts said in 2010 that 15 to 20 percent of the flat roofs in the country were green.
Green Roofs for Healthy Cities does not keep figures on the overall number of green roofs in North America, only on top cities' growth year over year. Washington has had the most yearly growth the past four years, Peck said.
Washington officials said the city has 2.3 million square feet of green roofs. Philadelphia reported more than 1 million square feet.
In 2011 in Chicago, in an effort to promote urban farming, the city passed a zoning ordinance specifically allowing rooftop farms to be built in the city.
Now Gotham Greens, a New York-based company, is set to open what it says will be the world's largest rooftop farm in August in the Pullman neighborhood.
The Far South Side community is home to a factory for Method, the eco-friendly soap company, which began a partnership with Gotham Greens last spring. When the farm opens, it will span 75,000 square feet, nearly 2 acres, and will yield produce equivalent to a 40-acre farm, Gotham Greens CEO Viraj Puri said.
Puri said a combination of Chicago's environmental initiatives and good timing helped bring the company to Chicago. When Gotham Greens was looking for a location in Chicago to expand its brand, Method reached out to propose a partnership.
"Chicago is kind of a green city, with a lot of sustainable building design and thriving local farming, urban gardens and rooftop farming scene," Puri said. "For a lot of reasons, Chicago checked a lot of boxes for us."
Like New York, Puri said, Chicago provides an opportunity to build upward.
New York officials said they did not have a tally of green roofs, but Gotham Greens already has three commercial rooftop farms in New York: 15,000- and 20,000-square-foot operations in Brooklyn, and a 60,000-square-foot rooftop in Queens that will begin crop production this year.
"We don't have a lot of open space, and even when we do, the soil quality is not good for food production," Puri said. "Increasingly, community groups, education groups, commercial enterprises look at rooftops as underutilized space for urban farming."
An improvement in technology also has contributed to the growth of rooftop farms.
At Method, a greenhouse will include sensors that track temperature, humidity, light, carbon dioxide and oxygen, eliminating the seasonal limitations of cities like Chicago with harsh winters, Puri said. A computer system will be used to adjust those levels as necessary.
Puri said Gotham Greens chose leafy greens to produce locally because they are highly perishable and don't store as well as other vegetables that have to be shipped long distances. The greens will be sold to local retailers, food distributors, restaurants and farmers markets.
Farther north sits a 20,000-square-foot rooftop farm on the McCormick Place West Building. The space, which opened in 2013, was the first rooftop farm built by the Chicago Botanic Garden. With the help of apprentices who work through an educational program, the rooftop provides about 10,000 pounds of produce each year to Savor, a restaurant and catering business based in the convention center.
McCormick's rooftop coordinator, Darius Jones, continues to look for ways to farm more efficiently. This year the team will produce only seven crops, down from 15 last year, maximizing the quantities of fewer vegetables. This season he planted kale, head lettuce, peppers, eggplant, tomatoes, radishes and carrots. Jones hopes to eventually expand the farm as well; there's more than 2 acres of available space on the West Building.
Smaller-scale rooftops also have opened or are proposed around the city.
Tracy Boychuk had a small rooftop garden built on the top of her garage in 2011 by Omni Ecosystems, a company that manufactures green roofs. While the space was being installed, she and Omni founder Molly Meyer discussed Meyer's business idea to bring more food-producing rooftops to Chicago residents. Boychuk was intrigued.
They expect their company, The Roof Crop, to be up and running this summer. Under their business plan, businesses and individuals with new commercial buildings would pay The Roof Crop to build farms, and The Roof Crop would then rent the space to produce crops. The Roof Crop would keep the proceeds from sales.
The Roof Crop is building a 6,800-square-foot rooftop farm on its West Town headquarters, as well as a 1,000-square-foot vertical green wall. Meyer and Boychuk, who plan to sell their vegetables to local markets and offer subscriptions, are also building a 1,000-square-foot indoor urban farm to support year-round crop production.
Omni Ecosystems employs an engineered soil system whose properties combat one of the pitfalls of rooftop farming _ the limited weight capacity on roofs, Meyer said. The material can be up to one-fifth the weight of a typical soil system, Boychuk said. Limitations on the weight of soil are just one of many obstacles rooftop farmers face.