The concept of using the large, flat rooftops of Athenian apartment buildings to grow fruit and especially vegetables is gaining popularity among city dwellers not just as a means to save money on basic food products, but also as a way of protecting buildings from the elements and helping reverse the effects of pollution.
It appears that the rooftops of a number of buildings in various parts of the Greek capital are already being converted into small gardens for vegetables, while owners at nurseries say that they have noted a rise in sales of herbs and vegetable seeds.
The idea of planting rooftops is nothing new. For example, in the United States a supermarket chain has already turned to buying from rooftop greenhouses and gardens, while the German company Schloss Wackerbarth produces wine from rooftop vineyards.
«There are very few large open spaces in cities,» argues Grigoris Kotopoulos, an expert at Egreen, a consulting firm in the application of green roofs. Planting a roof, he says, «is an opportunity to become creative and productive,» while he adds that a more systematic, large-scale approach to growing garden produce could gradually weed out many of the middlemen who make the cost of fruit and vegetables sold in cities so much higher than it would be if bought directly from the producer.
Kotopoulos also urges citizens to try rooftop gardening to grow their own fruit and vegetables for regular household consumption.
«This would give us all the benefits of rooftop gardening,» he said, adding that «the greenery protects the building from heat, while the crop makes for an excellent roof sealant.»
According to Kotopoulos a rooftop that can be turned into a garden must be able to sustain a minimum of 150 kilos per square meter. Growing trees is almost impossible, except in certain buildings that have been constructed along the lines of the latest codes.
«Even if a rooftop cannot sustain a large garden over its entire area, you can still plant crops on the perimeter,» said Kotopoulos. «Furthermore, you can choose crops that don’t grow to great depths, such as lettuce, cabbage, onion, eggplant, melon and strawberry. Beans and tomatoes, and fruit trees such as lemon, orange, peach and apricot, require much deeper soil to grow.»
Watering a roof garden can become very expensive, the expert warns, unless a tank is installed to collect rainwater, but the cost of electricity is negligible.
Kotopoulos stresses that anyone embarking on a green rooftop project must first have a study conducted into the exact climatic conditions of the area, such as hours of sunlight and annual rainfall.
There are three successful examples of green roofs to be found in the central neighborhood of Petralona alone in the Greek capital.
The first is located on the building right across the street from the Dora Stratou Theater in Ano Petralona and was designed by architect Eleanna Horiti, who wanted to create a continuum with Philopappou Hill and planted the garden with lavender and wildflowers, and even a few olive trees.
On nearby Georgiou Kolokotroni Street, architect Sofia Tsiraki designed two flat-roofed buildings that now boast pomegranate and lemon trees, while on Roumelis Street, Stella Constantinidi planted the perimeter of the rooftop with indigenous Mediterranean shrubs.