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 conservative 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.
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 continuous 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 conservative includes an agent to lower the pH of the solution, which encourages hydration. This is typically a mild acid such as citric acid.
Control Bacteria: The water in the vase or container can quickly become a bacteria soup. All it takes is a few stray pieces of plant tissue and some latent bacteria. Add some sugar from the conservative and you've got a recipe for cloudy, smelly water. The problem is not just an aesthetic one. Bacteria in the water will form plugs in the stem of the flower, blocking the water from flowing through the stem of the flower. A good floral preservative contains an antibacterial agent to stop all of this from happening.
Here's an ugly secret about these packs. Most packages are 5 gram packs which make one pint of solution. Most average vases hold at least one quart of water. If you do not follow the instructions for mixing the vase solution, and end up making a solution that is too weak, you may be providing enough sugar to grow bacteria while not providing enough antibacterial agents to stop the growth. This is a case where clear water with no preservative would be better than an improperly mixed solution. As soon as you notice that the water in your vase has started to become cloudy, it's time to dump the water, rinse the stems, give them a clean cut and put them back in the cleaned vase with fresh water. This alone will double the life of your flowers.
Unfortunately, some flower distributors believe that the consumer's initial perception is all that matters. They believe that the most important factor when choosing a conservative packet to distribute with their flowers is the price. They will not spend the extra three to five cents to provide the 10gram packet that should be provided. Instead, they believe that the consumer will be satisfied with any packet because they do not know any better. That shortsighted view means that consumer's overall perception of flowers is that they do not last as long as they should, and the water gets dirty and smelly very quickly. In the long-run, these consumers may turn to alternate gift ideas other than flowers, and this hurts the floral industry as a whole.
As a consumer, you should insist upon the proper conservative. It's worth the investment if you need to purchase an extra packet or two when you purchase your flowers. You can double the life of your flowers!