Dung tea trees that grow naturally in Canh Lien upland are shared by farmers to sell to Mr. Nguyen Canh Duy, owner of Cazin, in Canh Loi village, Canh Vinh commune, Van Canh district. Dung tea usually grows naturally on bare slopes, little old trees because they like light. People harvest the most i

n the summer and autumn. This time the tree leaves are not too young, nor too old, convenient for drying. When dry, the leaves are usually lemon yellow.