Mexico City has a literally breath-taking problem: smog. For years now, the city’s administration has been vainly attempting to combat it. Last year, the authorities responsible even had to declare a state of environmental emergency. Remedial assistance is now to be forthcoming from vertical gardens, which a citizens’ action group has installed on more than 1,000 concrete pillars in the Mexican capital. 60,000 square meters more green area and 27,000 tons of filtered air per annum – that’s the essence of the idea behind “Via Verde”. The additional plants filter out exhaust gases, fine dust and heavy metals, thus ensuring a better quality of air. With real success, as initial studies have evidenced: in the newly greened areas, the air quality is indeed gradually improving. So far, oxygen has been produced in this way for more than 25,000 residents.