Click on More information tab to get germination instructions (may be not available yet).
|Germination||Wild sunflowers can be slow to germinate, and they benefit from cold-moist stratification. Sow outdoors 2-3 weeks before the last frost date. Sow in fall in mild winter areas. Or sow the seeds indoors, in moist peat moss, and put them in a plastic bag, then refrigerate for 3 weeks. Once they germinate and can be manipulated, transplant them outside.
When sowing outside, first prepare the seedbed, then sprinkle seeds thinly and evenly on the surface and rake them in lightly, carefully covering them with soil and firm. Label each row and water gently but thoroughly with a fine spray. To prevent overcrowding, the seedlings usually need to be thinned. Water the newly establishing seedlings fairly frequently until the roots have developed. Support is required for the sunflower stems.
Notes: What is usually called the flower is actually a head (formally composite flower) of numerous flowers (florets) crowded together. The outer flowers are the ray florets and can be yellow, maroon, orange, or other colors, and are sterile. The florets inside the circular head are called disc florets. The disc florets mature into what are traditionally called "sunflower seeds", but are actually the fruit (an achene) of the plant. The true seeds are encased in an inedible husk.
Sunflowers in the bud stage exhibit heliotropism. At sunrise, the faces of most sunflowers are turned towards the east. Over the course of the day, they move to track the sun from east to west, while at night they return to an eastward orientation. This motion is performed by motor cells in the pulvinus, a flexible segment of the stem just below the bud. As the bud stage ends, the stem stiffens and the blooming stage is reached. Now the stem is frozen, typically in an eastward orientation. The stem and leaves lose their green color. The wild sunflower typically does not turn toward the sun; its flowering heads may face many directions when mature. However, the leaves typically exhibit some heliotropism.
|Price View||Tranche de prix|