Helianthus annuus is known as the classic sunflower, Kansas Sunflower or Mirasol and is a native to the Americas in the Asteraceae family, with a large flowering head (inflorescence). The term "sunflower" is also used to refer to all plants of the genus Helianthus, many of which are perennial plants. The Helianthus annuus is a coarse, hairy, leafy, fast-growing annual, which produces numerous 3 to 6 inch flower heads on branching stems and should not be confused with the many large hybrid sunflowers used in bird seed. The stem of the flower can grow as high as 3 meters tall. The plant takes 90-110 days to mature and they bloom in the summer season. The heads and plants are very large in cultivated forms. The flower head (golden-yellow rays with dark brown disks) reaches up to 30 cm in diameter with the "large" seeds. The stem has showing hairs, and these hairs make the stems feel extremely coarse. The green leaves are also coarse. Sunflowers plants are prolific breeders and you can expect this plant to produce at least hundreds of seeds! Hardiness zones :3-9, (-37c/-35f, -5c/25f).This plant is easily grown in average, moist, well-drained soils in full sun. Classic Sunflower tolerates poor soils that are on the dry side. To grow well, the sunflowers need full sun. In commercial planting, seeds are planted 45 cm (1.5') apart and 2.5 cm (1") deep. Irrigation is required until they become established. Sunflowers are cultivated as ornamentals or garden plants, where the blooms are cherished for their beauty and the seeds can be eaten by both humans and wildlife. Game birds, songbirds, and rodents eat the large, nutritious seeds of sunflowers. These attractive weedy plants are of outstanding value to wildlife in the prairies and other parts of the West.