Maturity and Quality
Sunflowers are normally harvested when the ‘petals’ (the outer flowers or ligules) have unfolded and are at least vertical. For local market, flowers are harvested with the ligules fully expanded and horizontal. No yellow or wilted leaves should be present. Length of life often is determined more by leaf yellowing or desiccation than by flower problems.
Grading and Bunching. Quality sunflowers are of uniform maturity, are free from defects, have straight stems, and have good quality foliage. Smaller-flowered cultivars may be bunched in 10’s or 12’s, and large-flowered types are normally packed individually.
Postharvest Handling and Storage
Sunflowers can safely be stored at 0-1ºC.
Prolonged exposure of sunflowers to low concentrations of ethylene results in abscission of ligules.
Pretreatments
The tendency for sunflowers to wilt prematurely in the vase can be avoided by pre-treating the flowers (15 to 30 minutes) with clean water containing 0.02% detergent (Tween-20, Triton X-100, dishwashing detergent).
Packing
Sunflowers are normally packed in standard horizontal flower boxes.
Special Considerations
Sunflowers are also somewhat sensitive to gravity. If held horizontal at warmer temperatures the flower heads will be permanently bent down, so it is important to maintain cool temperatures during transport and storage.
Disorders
Description
Helianthus annuus. In recent years, smaller cultivars of sunflower have become a very popular florist item, and a range of forms and colors are now widely available in the trade. Helianthus is derived from the Greek ‘helios’, the sun, and ‘anthos’, a flower.