The fluff stops here: Beijing’s battle against the green wall ‘snowstorm’

Beijing residents are once again bracing for a seasonal nuisance that has become something of a tradition: the city’s annual “snowstorm” of willow and poplar catkins. The catkins are essentially seeds from female willow and poplar trees, encased in downy fibres. After pollination in spring, the female trees produce seed pods that split open upon ripening, releasing the fluffy seeds to disperse in the wind. The wisps absorb bacteria, pollen and dust from the air, triggering respiratory and skin...