The Mexican army says it has discovered almost an acre (0.37 hectares) of opium poppies growing in the township of Ensenada, near the U.S border, according to AP. Soldiers destroyed the two poppy plantations in the hills near the Baja California city, which is about 60 miles (100 kilometers) south of the California border. Opium poppies are usually a mountain crop grown farther south in Mexico. But Mexican cartels have been expanding poppy production to export heroin to the United States. The army's Second Military Region said in a press statement Tuesday that the poppies were destroyed by cutting and burning. Smaller marijuana plots found in the same area Monday also were destroyed.