New York: Organic rooftop garden

"There's about 1000 worms in here," Annie Novak tells a journalist from the New York Times, holding up a box full of worms she is about to distribute in the roof garden in Greenpoint. Annie is Rooftop Farms' head gardener and hopes that the worms will make the soil in the vegetable garden even more fertile. The garden, 15 m above the Greenpoint sidewalk, is like a peaceful oasis in an otherwise throbbing industrial district. Several of the neighbours potter about in the garden, fussing with their potatoes and carrots with the Manhattan skyline as a backdrop.

The Rooftop Farms project started in 2008 when the Goodes, who own Goode Green, together with their partner Amy Trachtman, contacted the owner of numerous industrial buildings in Greenpoint with a view to establishing gardens on their rooftops. After the go-ahead was given by Gino Argento, who owns several of the industrial buildings and is something of a local celebrity, the stability of some 750 m² of roof was tested by a structural engineer.

About 90 tonnes of specially mixed soil from Philadelphia was spread on the roof in March 2009. The soil mix already contained compost and some 50% expanded shale, which make the mixture light and ideal for use on roofs. The garden is divided into 16 1.5 metre-high raised beds with mixed vegetables. Sweet corn, lettuce, radishes, herbs, red (bell) peppers, etc. are grown together in the beds to ensure nutritious soil and to limit the impact of pests. The garden users receive organic waste for their patches from the restaurants who by some of the vegetables, enabling them to avoid the use of artificial fertilisers.

The vegetable garden on Eagle Street, the first commercial roof garden in North America, has exceeded everyone's expectations. During the first year, almost 100% of the vegetables sprouted and its founders are very satisfied with the produce. 'The radishes are perfect,' says Annie Novak. With the assistance of a number of volunteers who help sow and reap the vegetables, as well as doing other odd jobs, the project has succeeded in producing vegetables that can be sold to local restaurants and Brooklyners. For the founders it is motivating to be able to offer vegetables in a neighbourhood that otherwise does not have particularly good access to good, healthy produce.

However, the vegetable garden has more advantages than just the healthy food it produces. Apart from the environmental benefits - the plants absorb rainwater that would otherwise flow into, and overload, the city's sewage system -irrigation is by rainwater only, which means it is not a burden on drinking water reserves. The layer of soil and vegetation helps to insulate the industrial buildings, thus reducing their energy consumption. Locally produced vegetables also reduce the carbon footprint because they do not have to be transported over any distance to consumers. The establishment of more roof gardens will also help to reduce the heat island effect experienced in large urban areas.