What's up with those little cellophane packets of powder that come with flowers?They contain a floral preservative that is a food, hydration agent and antibacterial treatment. Used properly, floral preservatives will greatly increase the vase life of your fresh cut flowers.
Food: The food the preservative provides is a sugar. Plants produce sugar through photosynthesis from water, carbon dioxide and sunlight. When a flower is cut from the plant, photosynthesis is no longer an option for the production of sugar. The sugar is needed to continue development of the flower bud into a flower. With this sugar, the flower will perform better in terms of size, color and vase life.
You can also buy fresh flowers from Magenta Flowers.
Hydration: While cut flowers will not photosynthesize, they will transpire. That is, water still is taken up by the stems and released into the air through the stomata. A turgid flower is a hydrated flower. A wilted flower is one where the cells do not have their full amount of water.
The outside ring of the stem of the flower, just under the bark, is made up of tiny tubes or vessels. This group of vessels or vasculature is responsible for transporting water from the roots, or vase in this situation, to the leaves and flowers. Water sticks to it self and in general will tend to be drawn up the stem by the continual evaporation of water through the pores in the flower and leaves.
However, when a flower has been dehydrated through the normal course of post harvest and shipping, the chemistry needs a jumpstart. When the pH of a solution is more acidic, the molecules are more hydrophilic… or they tend to stick together more. So, a good preservative includes an agent to lower the pH of the solution, which encourages hydration. This is normally a mild acid such as citric acid.