Gardeners in Xuchang, Henan province, inject chemical agent into a willow to control the spread of catkins on April 4. If catkins, snow white cotton-like fluff which come from willows and poplars in spring, are not controlled, then they could pose threat to residents' health and safety of public transportation, [Photo by Niu Yuan/Asianewsphoto] |
Related: Willow warning: Catkins are pretty, but carry potential health risks