The Industrial Revolution compelled workers to seek employment in cities, a trend that has never really reversed: According to the U.S. Census, in 2013, nearly two-thirds of Americans lived in cities.* Due to a finite amount of land, these cities are expanding, and more land is being incorporated every year.
The largest single land use in cities is residential, so what we choose to do with the space we inhabit is of interest to researchers who study urban environments. For example, the preponderance of residential land use means that residential gardens, including urban agriculture, are increasingly important sites of biodiversity (plants, animals, and micro-organisms) and agrobiodiversity (a subset of biodiversity concerned with food and agriculture) in cities.
But these urban sites of food production haven’t been studied extensively, at least not in the developed world, says Falk School of Sustainability Assistant Professor of Sustainable Agroecology John R. Taylor, PhD who is looking to change that. Further, he says:
“I thought that by doing this I could almost act as an advocate for home gardens. They do make a substantial and unrecognized contribution to urban food systems.”
Dr. Taylor grew up on a farm in Latrobe, PA where his family grew corn, soybeans, wheat, barley, oats, and raised cattle and hogs. In high school, he sold crops that he grew in his market garden. “I was like a little plant nerd,” he laughs.
For the current project, Dr. Taylor and his colleagues sought to understand food gardens of a subset of Chicago-area ethnic and migrant households. Dr. Taylor and his team interviewed 19 Mexican-origin, 23 Chinese-origin, and 17 African American gardeners (for a total of 59), catalogued what they were growing, and asked about their garden histories, gardening practices, and personal histories. Linguistically competent graduate assistants from the focal communities helped secure participation and facilitate interviews. The research, published on February 15, 2016 is entitled: “Ecosystem services and tradeoffs in the home food gardens of African American, Chinese-origin, and Mexican-origin households in Chicago, IL” by John R. Taylor et al in Renewable Agriculture and Food Systems, Cambridge University Press.
“Attaining a height of three or more meters…tropical corn is a striking botanical feature in Chicago neighborhoods, potentially acting as a signifier of regional and ethnic identity.”
Among their other findings:
- Only 9.6% of the inventoried species were native to Chicago.
- A total of 123 edible plant taxa were identified across the 61gardens, including 17 species of food crops, 27 species of culinary herbs, and 79 taxa of vegetable crops.
- Only three species (Jerusalem artichoke, pokeweed, and fox grape) were native to the Chicago area.
- On average, Chinese-origin households devoted a significantly higher proportion of their lot to food production than did African American or Mexican-origin households.
- Fruit trees were most abundant in Mexican-origin households’ gardens and least abundant in those of Chinese-origin households.
- Only winter squash appeared in the ten most abundant groups for all three samples.
- Ethnic food culture and preferences most strongly influenced the species composition of Chinese-origin households’ gardens.
Planting food for our own consumption might seem to be an unmitigated good to the non-agro-ecologists among us, but Dr. Taylor cautions that there are trade-offs.
“If urban gardeners use a lot of synthetic fertilizers a couple of times each week, that can contribute to storm water pollution. And planting perennial species limits the time that the ground can act as a hospitable environment for “good” insect species.”
Gardeners’ priorities might conflict with those of human urban dwellers, too. Take trees. “While vertical structures like trees are helpful in terms of supporting biodiversity, urban agriculturalists tend to not want a lot of trees, since they block sun,” says Dr. Taylor. But many people see trees as welcomed sources of shade that not only provide comfort, but also mitigate urban heat island effects. “City centers tend to be warmer than fringe areas because of the amount of concrete. This leads to increased costs in terms of cooling, and can lead to a serious negative impact on human health,” he says, citing the 1995 Chicago heat wave that led to 739 heat-related deaths.
“While the composition of the front yard purportedly reflects social class, backyards are alleged to be ‘dreamscapes’ reflecting the owner’s ‘true’ landscape preferences.” – Larsen and Harlan, 2006 (mentioned in Taylor et al, 2016)
Ultimately, Dr. Taylor is interested in evolving the project from descriptive study to experimental work, developing agro-ecological approaches to community gardens. “We could potentially take models provided by the Chinese-origin gardeners—like polycultures, trellises, and vertical gardening—and use them in new ways,” he says. “I’m interested in developing models where perennials, trees, shrubs, and other plants can grow together in a home garden that produces food and supports biodiversity.”
Dr. Taylor cites Pittsburgh’s Mt. Oliver Community Garden Gathering Space, a project run by Bhutanese refugees in conjunction with Grow Pittsburgh and GTech, as a way that culture and agriculture can come together to provide some degree of food security, companionship, and purpose to a migrant community.
The Falk School of Sustainability offers an M.A. in Food Studies (MAFS), a Master of Sustainability (MSUS), a Bachelor of Sustainability, and dual-degree MAFS/MBA and MSUS/MBA programs. Learn about growing food at Eden Hall.
*Population Trends in Incorporated Places: 2000 to 2013 Population Estimates and Projections Issued March 2015 P25-1142 By Darryl T. Cohen (With Geoffrey W. Hatch)