Ancient Persians were growing their own type of saffron ( Crocus sativus ` Hausknechtii ' ) in Derbena , Isfahan , and Khorasan by the 10th century BC . Ancient Persians cultivated Persian saffron ( Crocus sativus ` Hausknechtii ' ) in Derbena , Isfahan , and Khorasan by the 10th century BC .