Rooftop gardens in cities could provide more than three quarters of the vegetables needed by the inhabitants, a case study from Bologna, Italy, suggests.
If all suitable flat roof space was used for urban agriculture, rooftop gardens in the city could supply around 12 500 tons of vegetables a year whilst also providing a range of ecosystem services, the researchers say. Any unused roof space in a city represents an opportunity to add to that city’s green infrastructure.
Urban green spaces and infrastructure, which include rooftop gardens, offer benefits for both wildlife and people. Not only can they produce food for city-dwellers, they can increase urban biodiversity and link together to form green networks, acting as corridors for wildlife.
They can also reduce a city’s ecological footprint by filtering polluted air, absorbing noise and CO2 emissions, and controlling temperature by shading.
In 2010, Bologna became the first Italian city to test rooftop vegetable gardens on public buildings, as part of a project led by the local authority, university and a non-profit organisation.