For those of us who have placed our faces or cameras close to a sunflower in bloom, we know that the sunflower head is not a single flower as the name implies but is made up of over 1,000 individual flowers joined at a common receptacle. It is commonly believed that the sunflowers turn their heads to follow the sun each day but only the immature and developing flower heads do this. Sunflowers will grow in a wide range of soils from sands to clays. They prefer to be direct seeded after all danger of frost. Plant when day and night temperatures are above 50 degrees Fahrenheit and optimum temperatures for growth are 70 to 78°F. Sunflowers need at least six hours of full sun a day and should be spaced per planting instructions.
Good soil drainage is important and watering deeply but infrequently will encourage deep roots and strong stems. A critical time for water stress is the period 20 days before and 20 days after flowering, adjust watering accordingly. Avoid high nitrogen soil that encourages plant growth but fewer blooms. Sunflowers can provide a beautiful privacy screen, but they can easily block needed sun, so place them accordingly in your garden. Sunflowers emit substances that inhibit growth of certain plants, particularly potatoes and pole beans. Many new varieties have been developed. Multi-branched varieties form a quick, annual screen. Dwarf types are suitable for planters and low borders. Pollenless varieties won’t stain your linens but still provide nectar for butterflies and bees. For example Moon-walker, blooms with several pale yellow flowers on top of eight-foot branching stalks. Dwarf varieties include Music Box, which are a branching, two-and-one-half foot tall plant. Big Smile grows only one-and-one-half feet tall and produces one, five-inch golden yellow bloom with a brown center. It's a perfect sunflower for containers and flower beds.
Soraya is the first sunflower in All American Selections history to earn an AAS Award. One of the distinct qualities is orange petals; most sunflowers have golden petals. Named after an ancient European princess, 'Soraya' plants are branching and produce 4 to 6 inch blooms on long stems perfect for cut flowers. In a vase, 'Soraya' blooms are perky for 7 days with excellent leaf and flower quality for homes. Easily grown from seed, 'Soraya' will flower in about 90-100 days. Plants are self supporting and need full sun to attain a height of five to six feet. 'Soraya' flowers can produce seed for birds if left on the plants to mature. To harvest sunflower seeds, place netting or cheesecloth over the flower head as the seeds are forming. When the flower heads are turned down, the florets in the center of the flower disk are shriveled, and a lemon yellow color is on the back side, cut the seed head with about one foot of stem attached. Hang the seed head in a warm, dry and well-ventilated place free of insects and rodents. Place a paper bag with holes or cheesecloth over the heads to catch the falling seeds as they drop during drying.
Genus, species: Helianthus annuus Common name: Sunflower http://www.colostate.edu/Depts/CoopExt/4DMG/Whats/Amerslct/sunflwer.htm