Description
The common sunflower is an annual of the daisy family (Compositae) from the western regions of North America. It has a single or sparsely branched, straight stem 50 to 200 cm tall, hollow, green with irregular brown spots and roughly hairy. The leaves are heart-shaped, large and, like the stems, roughly hairy.
It flowers from July to October. The flower heads can be single, with long, usually yellow ray florets and brown disc florets, or double. Varieties are available with one very large flower head per stem, and others with many smaller heads. Ornamental varieties differ in stem height and in the structure and colour of their flower heads.
Requirements
It needs fertile, deeply cultivated, moderately moist soil and a sunny position.
Propagation
Sunflowers are propagated by seed sown directly outdoors in April. The plants should grow at a spacing of 60 x 30–40 cm.
Care
Sunflowers are planted in rows or groups along fences and the walls of buildings, and are also used as cut flowers.