People learn about 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)