Participants trim bonsai trees during a competition at the International Green Days Fair in Warsaw, Poland, on March 22, 2019. The third edition of International Green Days Fair opened here on Friday. As one of Poland's largest horticulture and garden landscaping fairs, the fair showcases living room architecture, gardening tools, as well as flowers and plants for gardening enthusiasts and resellers. (Xinhua/Jaap Arriens)