Simon Wilson: The vege gardens of Rio's favelas

Workers in the Hortas Cariocas: the gardens of Rio.

They reckon it will be the biggest urban garden in the world. Hortas Cariocas, the Gardens of Rio de Janeiro, is a series of vegetable gardens surrounding some of the favelas of Brazil's second-largest city. The project was started in 2006 and by 2024 is expected to be as large as 15 football fields, growing enough food to feed 100,000 families. And more than that, to provide the workers in the gardens with income.

Give someone a fish, the old saying goes, and they eat that day. But give them a net and they can build themselves a life. Assuming there are still fish, that is. The city version is about food banks: give a family a food parcel and they eat that week. But right now, in Rio as in Auckland, as in cities all over the world, the demand for food parcels has exploded. Give a family access to a bit of land and a co-operative endeavour to grow food, and you can help them change their lives.

Hortas Cariocas makes organic food affordable and accessible. "The result of our project is not to have a beautiful garden," says Julio Cesar Barros, director of agroecology organic gardening for Rio de Janeiro's municipal environment agency. "A beautiful garden is a consequence of our work. The result of our production is to see how many plates of food we are able to serve."

Growing food for the community, Rio de Janeiro.

Hortas Cariocas has 56 active community gardens, 29 in favelas and 27 in schools, together employing 40 gardeners and producing about 80 tonnes of food. With active support from Rio's mayor, Eduardo Paes, the plan is to double production, with the number of gardeners increasing to about 90.

Half the food is donated to people in need – food banks won't be surplus to requirements anytime soon – while the other half is sold by the gardeners at affordable prices for the community. The goal is for each garden to become independent and self-sustaining, with the gardeners and the volunteers who work with them deciding for themselves how and when to make that work.

Economic viability is critical. Hortas Cariocas is in an area that used to be known as "cracolandia": the city's largest area of crack cocaine consumption. "Before," says Barros, "you would open your door and see Crackland. Today, you open your door and see a garden."

As cities get denser, we're all going to need more of this.

Even when the houses are packed together, everyone needs access to a garden.

Design for Living is a series about good ideas that make cities better, appearing weekly in Canvas magazine.