Though it may sound surprising, researchers have shown that certain crops grown in cities can yield as much as two times the harvest of rural plots. Cucumbers, potatoes, and lettuce are among the species that appear to perform especially well in urban environments, according to a recent scientific finding.
As urban populations rise, city farming is increasingly seen as a local food source that can trim grocery costs and supply healthy produce. Yet until now, urban agriculture’s outcomes were rarely compared directly with traditional rural farming. A new study published in The Future of the World AGU indicates that urban gardens and hydroponic systems can match, and in some cases exceed, the yields of conventional farms in rural areas.
“Even as urban farming grows in popularity, there is still much we do not know about its yields, including how they compare to conventional farming and which crops do best in city settings,” notes Florian Payen, an environmental scientist at Lancaster University and the study’s lead author.
The researchers synthesized studies on urban agriculture from 53 countries to uncover which crops thrive in cities, which growing methods work best, and where urban plots can be located for cultivation. They found that for certain crops, such as cucumbers, tubers, and lettuce, urban yields can be two to four times higher than those seen in conventional agriculture. Many other crops grown in urban settings were produced at comparable or higher rates than in rural environments.
Much of the prior work in urban agriculture focused on green spaces like private and community gardens, parks, and field farms. Payen’s team broadened the lens to include “grey” areas—roofs and building facades that already exist in cities but can host farming. The study evaluated a range of crops produced under both natural and controlled conditions, across green and grey spaces, using soil and hydroponics, and in horizontal and vertical growing systems.
“Surprisingly, there was little difference in total yields between indoor and outdoor green spaces, but crop suitability varied by built environment,” Payen explains. Some crops, such as lettuce, cabbage, and broccoli, are naturally more amenable to vertical, indoor growth than others. “You can’t quite stack apple trees in a compact high-growth chamber,” he concedes, “yet one study did report success with stacked wheat in such a setup.”
Other crops, including tomatoes and leafy greens, performed well under hydroponic systems. Fully controlled environments can support year-round production, driving more frequent harvests and, in many cases, higher annual yields than outdoors. However, the researchers caution that more work is needed to translate these findings into profitable farming models.
Environmental scientist Erica Dorr of AgroParisTech, who was not part of the study, described the results as aligning with expectations from urban farming researchers. Current estimates suggest that a modest share of legumes, vegetables, and tubers are grown in urban contexts, with cities contributing a meaningful portion of global food production. Pinpointing how much food a city can generate, however, requires robust performance data like that provided by Payen’s analysis.
This is the first step, Payen says. Once scientists have precise yield estimates for urban crops, they can map a city’s potential growing zones and quantify how much food could be produced locally.
“That dataset offers planners and policymakers a clearer view of whether investments in roof gardens, greenhouses, or hydroponic systems will pay off,” he adds. The work also supports forecasting how cities might meet future food demand and the degree to which urban areas could become self-sufficient in food production.
One barrier to progress has been a lack of reliable data on urban yields. Payen notes that conversations with government agencies and local councils repeatedly surfaced the same concern: without dependable data, it is hard to justify funding urban farming initiatives. The current study helps fill that gap and supports the ongoing push to measure and scale urban food production.
Questions remain about the relative carbon footprint of food grown in cities versus conventional farming, with outcomes likely varying by locale and farming method. Researchers are also examining how urban-grown foods may be affected by local pollution.
For further reading, the referenced work is available in the AGU’s journal collection as a study on urban crop yield across multiple growing systems. The findings were produced through a synthesis of international research and are intended to guide urban planners, researchers, and policymakers in evaluating future food strategies.
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Note: contact details and publication metadata have been omitted for clarity and regional accessibility. The study references data-informed frameworks and theoretical models designed to inform city-scale food planning and policy development in North America and Europe.