People learn about the technique of pollination in growing heirloom tomatoes during the 8th Annual Heirloom Tomato Fest at Earthwise Garden in Delta, Canada, Sept. 14, 2019. The 8th Annual Heirloom Tomato Fest features a variety of certified organic heirloom tomatoes together with heirloom tomato sale, cooking demonstrations, and heirloom tomato growing workshops. (Photo by Liang Sen/Xinhua)