The idea of Hong Kong wedding banquets offering locally grown produce rather than exotic species, or of a restaurant serving vegetables grown on its rooftop, might seem of little more than novelty value. Such ventures are a rarity in the city and there is certainly an element of trying to be different about them. However, the people behind them are not about fads and turning a quick profit, but making our city more sustainable and healthy. It is the kind of thinking that we should be making every effort to embrace and encourage. Growing locally has a myriad of advantages. Produce is fresher, there is less risk of contamination and transport costs are lower. Because we have better knowledge of where our fruit and vegetables come from and how they are produced, we have greater assurance of quality. Each time we buy locally, we are helping local farmers. Land is, of course, in short supply and far more valuable for property development than as farmland. Our agricultural sector has shrunk to the point that just 3 per cent of what we eat is produced locally. Cost is a big factor - mainland suppliers can sell produce in Hong Kong for at least 20 per cent less than local varieties. But with affluence also comes the possibility of choice and we have developed an appetite for the premium, unusual and exotic. The succession of mainland food health scares, inflationary pressure on prices and our feeding frenzy that has left fish species endangered dictate that we should change our ways. While growing all our needs locally is impractical and an impossibility, we should be investigating using rooftops, fence lines, highway verges and disused former farmland to produce some of our fruit, vegetables and herbs. It is not a strange or faddish idea - communities elsewhere that value taste, freshness and healthy eating are increasingly making the switch. Urban farming would make our city cooler and greener. They are benefits not to scoff or turn up our noses at, but to embrace.