60 Days to maturity. Helianthus annuus. Canyon Sunset Sunflower Seeds: Non-GMO. hybrid. Ornamental. Annual. A lovely pollen-less F1 hybrid single-head sunflower, Canyon Sunset can grow up to 7 feet tall. With golden petals and a brown face, this sunflower is a beauty. The flower heads can reach 9 to 11 inches wide. Canyon Sunset does well in bouquets and can last up to a week after being cut. Approximately 400 Seeds / Ounce.