Heroin does not grow. It is a chemical derived from morphine, which itself is derived from opium. Opium is derived from poppy flowers and the poppies grow in mountainous regions on very poor dry soils in places like Afghanistan,Pakistan and China. The poppies survive drought when other food crops fail. The poppy seed heads are cut with a knife and the white sap oozes out and dries to a brown hard resin. This is hand picked and refined as above.