Each large city can grow 82% of the vegetables it consumes

When we consider that we import peppers from Chile, cucumbers from Tunisia, tomatoes from Spain, we have to conclude that this is not entirely sustainable. However, research into the possibilities of growing one’s own vegetables in the area of ​​a large city reveals an interesting relationship.

Berlin has plenty of room for urban gardening, and up to 82% of Berlin’s vegetable consumption could be produced locally, according to a new study. “The amount of vegetables is a significant part of the annual consumption,” says Diego Rybski, foreign professor of the center. Center for Complexity Science and co-authored an article to be published in the April issue of Sustainable Cities and Society.

See the report on community gardens:

Rybski and his team wondered how much vegetables could be produced in Berlin. They assessed a total of five urban sites for agriculture—underdeveloped residential areas, horticultural colonies, rooftops, supermarket parking lots, and indoor cemeteries.

A city with traditions

Berlin was not chosen by chance. Urban gardening has a long tradition in Berlin, with over 200 community gardens and over 73,000 colony gardens in the city. However, Rybski says that green spaces between rooftops and unimproved housing estates — large housing complexes — offer a huge opportunity for urban gardening because they are underutilized.

“Given Berlin’s car-free plans, parking lots are also good candidates for growing vegetables,” adds Rybski, a researcher at the Potsdam Institute for Climate Impact Research and the Wuppertal Institute.

As a result of the research, it was found that a total of 4154 hectares of Berlin can be used for growing vegetables. This is almost 5% of the total area of ​​the city. The newspaper reports that 82 percent of Berlin’s vegetable needs could be met from local sources if all that land were used for urban gardening. To realize this production, it would be necessary to invest in water, human resources, investments. For example, a total investment value of €753 million would be required, which is just under 0.5% of Berlin’s gross domestic product (GDP) in 2020.

Big problems

As Rybsky points out, promoting urban gardening would be a big challenge given the high consumption of resources. “There is room there, but we have to consider a number of factors. For example, who will do the gardening? Can these be private gardeners or do we need a business model? What should be done to increase production in gardens? How can we create conditions to support urban agriculture in the city?”, asks the researcher.

“In principle, I believe that this will be a positive development. Marion De Simone, lead author of the study from the Potsdam Institute, says that locally grown vegetables would probably be more expensive, but we could create some kind of label for them – like an organic label.

The benefits of local gardening are many. “Just to name a few: community gardens bring people together. Green spaces benefit human health as well as the environment and biodiversity. Local food production also reduces carbon emissions from transport,” adds co-author Prajal Pradhan of the Potsdam Institute. The entire study can be found here ScienceDirect.

But what if it’s not just Berlin?

What if we take this to other cities? To increase the yield of vegetables, it is not necessary to grow them immediately in all possible areas. But what if we start thinking at half the limits (about 40% of consumption) in, for example, Prague, Brno or any other Czech or Moravian (European) city? What if we shift the responsibility of cultivation from the big companies to ourselves?

Not only would we be contributing to the planet, but we could also be healthier. Exactly. Other studies show that it also helps people. In early January, the University of Colorado presented the first randomized controlled trial of community gardening. Lancet Planetary Health. He found that those who gardened ate more fiber and were more physically active—two known ways to reduce the risk of cancer and chronic disease. They also experienced a significant reduction in stress and anxiety levels.

“Increasing one gram of fiber can have a huge positive impact on health,” said co-author James Hebert, director of the University of South Carolina’s Cancer Prevention and Control Program.

The gardening group also increased their physical activity level by approximately 42 minutes per week. Although doctors recommend at least 150 minutes of physical activity per week, only a quarter of the US population meets this recommendation (we’re talking about the US, because that’s where this study comes from). By visiting just two to three community gardens per week, participants met 28% of this requirement.

Study participants also experienced reductions in stress and anxiety levels, with the most stressed and anxious participants in the study experiencing the greatest reduction in mental health problems.

Resources: ScienceDirect, Center for Complexity Science, Lancet Planetary Health