Osteospermum, commonly known as the African Daisy, possesses specific physiological characteristics that directly influence its performance as a cut flower. As a member of the Asteraceae family, its "flower" is actually a composite inflorescence made up of central disc florets surrounded by ray florets (the colorful "petals"). The plant is naturally adapted to sunny, well-drained conditions. When cut, this vascular system is severed from its water and nutrient source. The primary challenge becomes preventing xylem blockage (the plant's water-conducting tissues) and maintaining the turgor pressure within the cells of the ray florets, which are crucial for keeping the bloom open and vibrant. Its natural resilience to somewhat dry conditions can be a slight advantage, but it does not negate its absolute need for a clean water supply post-harvest.
The stage at which an Osteospermum bloom is harvested is critical for its vase life. The optimal time for cutting is early in the morning when the plant's stems are fully hydrated and temperatures are cool. The flower should be chosen at a specific stage of development: select blooms that are just fully open. Avoid buds that are too tight, as they may not open properly in a vase, and avoid flowers that are overly mature, as they will decline more rapidly. Using a sharp, clean knife or pruners, make a diagonal cut on the stem to maximize the surface area for water uptake. Immediately after cutting, place the stems into a bucket of clean, lukewarm water.
Proper post-harvest handling is paramount to extend the vase life of Osteospermum. Before arranging, all foliage that would sit below the waterline in the vase must be meticulously removed. Decaying leaves will rapidly decompose, promoting the growth of bacteria that will clog the stem's vascular system and shorten the flower's life. It is highly beneficial to re-cut the stems under water before placing them in the final vase. This prevents air embolisms (air bubbles) from entering the xylem vessels and blocking water flow. The vase itself should be impeccably clean to minimize bacterial contamination. Fill it with fresh, lukewarm water and add a commercial flower preservative. This preservative provides carbohydrates for nourishment, acidifiers to improve water uptake, and biocides to suppress microbial growth.
Under ideal conditions, with proper harvesting and meticulous care as described, cut Osteospermum flowers can be expected to last in a vase for 7 to 10 days. Several environmental factors will influence this duration. The single most important factor is water quality and cleanliness; cloudy, bacteria-laden water will cause rapid wilting. The flowers must be kept away from direct sunlight, heating vents, radiators, and ripening fruit. These sources expose the flowers to excessive heat and ethylene gas, a plant hormone that accelerates senescence (aging and death). Drafts can also cause excessive water loss through transpiration. Recutting the stems and changing the water with fresh preservative every two days will significantly combat bacterial growth and maintain clear water pathways, directly contributing to achieving the maximum potential vase life.
