Do Sunflowers Wilt at Night?

Flower Form

• Sunflower blooms may look like one large flower, but are actually hundreds of small flowers clustered together. These small flowers produce pollen, and eventually sunflower seeds, although varieties used for cut flowers are usually pollenless and do not produce seed. The flowers form on sturdy stems that become somewhat woody as the season progresses. They do not wilt at night but remain open for up to two weeks.

Heliotropism

• Although sunflowers don't wilt at night, they do perform an interesting trick daily. When the flowers are in the bud stage, they move during the day so the face of the flower follows the path of the sun from east to west. At night, the sunflowers return to an east-facing orientation. Once the flowers bloom, they remain facing east. This phenomenon is known as heliotropism.

Vase Life

• Sunflowers make excellent cut flowers because of their sturdiness and long bloom time. Not only do sunflowers not wilt at night, they may last more than a week as a cut flower. Cut flowers in the cool of the evening or morning, when the sunflowers are dry and free of dew. Cut them with scissors or a sharp knife and remove the foliage, leaving a long stem. Place them in a vase filled with clean water. Add a commercial floral preservative to extend their life.

Variety

• How long a sunflower blooms depends in part on the variety. For cut flowers, select pollenless varieties with a long bloom time. Try Bronze King, Full Moon, Golden Queen, Floristan, Full Sun, Valentine, Sonja or Sunbright. Some plants have a branching habit, producing multiple flowers, while others grow on upright, erect stems, producing one or two flowers at a time.