Times such as optimum sowing, planting, germination time and duration, fertilization, agricultural pest control, irrigation time, harvest, plant growing stages can be determined by using the Growing Degree-Day (GDD) values. The Isparta region has an ideal climatic area for oil rose growing. For this purpose, meteorological stations were chosen as the study area for Isparta provinces and districts having the most suitable growing ecology in oil rose cultivation. Oil rose is a perennial plant with an active growing period of about 120 days depending on the phenological periods. Different GDD values for different phenological periods were acquired when the GDD values for the active growing period of the oil rose plant were correlated with the elevations of meteorological stations at different locations. It was determined that the study area was divided into 4 groups by the statistical Duncan test, which was made according to the growing degree-day values and optimum temperatures. It was determined that the Sutculer district is the most suited growing area for the oil rose plant followed by Atabey, Egirdir, Isparta, Keciborlu, Senirkent and Uluborlu.