On a sunny weekday, Hongkonger Lai Yee-man, 70, pulled weeds from a plot of leafy vegetables, shielding her face from the sun with a large white hat.
But Lai was not on a typical farm; she was on the rooftop of a shopping centre in the middle of an urban neighbourhood.
“When Hong Kong people come here, they are surprised to see the vegetables. They say ‘Oh wow, that’s how eggplants are grown!’ Some kids have never seen these things being grown,” said Lai, pointing to bell peppers, dragon fruit,…