Food security may be less of an issue for urban dwellers than previously thought.
Take the case of 70-year-old Andy Hoi-Csiu Chan. He tends bamboo, peonies, watermelon, eggplants and other vegetables in his Chicago backyard. Chan, an immigrant from China who teaches traditional brush painting at his Chinatown studio, started his garden about 12 years ago.
"I love to see that they grow," he said. "Many, many friends to come to my house and I cook for them." Even in January, Chan keeps a stock of vegetables from his garden grown the previous summer.
Chan is a member of a significant and previously undocumented population of Chicago urban farmers. Though Chan said he wasn't aware of it, researchers at the University of Illinois recently discovered that many of his neighbors, especially those of Chinese origin, are also enjoying the fruits and vegetables of backyard gardening.
Based on the number of newly located food-producing backyards, Chicagoans may be more protected from future climate-induced food shortages and food price swings than some researchers have thought. The study sheds more light on food security issues that could arise as more people around the world are moving to cities.
Using satellite images from Google Earth, researchers Jon Taylor and Sarah Taylor Lovell have produced a new, more accurate study of Chicago's urban agriculture sites, revealing a significant number of home gardeners like Chan.
Taylor, a doctoral candidate at the University of Illinois' Department of Crop Sciences, and Taylor Lovell, an assistant professor in the same department, discovered that residential gardens accounted for almost three-fourths of the total area of Chicago's urban agriculture sites.
Taylor and Taylor Lovell also found that earlier records of Chicago's community gardening sites, mostly provided by local nongovernmental organizations, were misleading. Among the 1,236 sites listed as community gardens, only 13 percent were actually growing food.
Hunting vegetables by satellite
The project began as an attempt to locate community gardens for use as research sites. Using the only lists available, Taylor and his fellow researchers learned that many of Chicago's recorded community gardens were actually ornamental gardens, playgrounds or parks.
"We kept visiting gardens thinking, 'Oh, there are vegetables here,' and there weren't," Taylor said.
In an attempt to identify workable research sites, Taylor and his fellow researchers turned to satellite images on Google Earth.
"We noticed that we could actually look in people's backyards and identify the larger sites of food production on private lots," he said. "I was surprised by the size of some of the backyard gardens."
The researchers decided to manually survey the quantity and area of Chicago's urban agriculture. Taylor examined hundreds of high-resolution aerial images of Chicago's neighborhoods on Google Earth. By searching for signs of vegetation, raised beds and tilled earth, he was able to mark the location and size of both community and residential gardens.
To account for the Chicago area's 234 square miles, Taylor spent about 400 hours in front of a computer screen and visited almost 200 undocumented community gardens to confirm his findings.
Ultimately, Taylor was able to identify 4,648 urban agriculture sites in the city of Chicago, with a total production area of 315,958 square yards -- enough garden sites to fill almost 50 football fields. Most of these sites -- 86 percent -- were identified as food-producing residential gardens.
Taylor believes his official report of about 120,000 residential garden sites is a conservative number. Google Earth's satellite images aren't detailed enough to show smaller gardens, he said. "I think people will find a way to garden, no matter how small the space is."