Final answer:
To extend the shelf life of a bouquet of flowers, use a flower preservative consisting of sugar for nutrition, bleach to inhibit bacteria, and an acidifier to maintain pH levels.
Step-by-step explanation:
To extend the shelf life of a bouquet of flowers in a vase, the best additive to include is a flower preservative, which often comes with the flowers from the florist, or you can make your own at home. A simple and effective homemade preservative can be made from sugar, which provides nutrition to the flowers, bleach, to keep the water from getting cloudy and inhibit the growth of bacteria, and an acidifier such as lemon juice or vinegar, which helps to maintain the water's pH level and enhance the uptake of water and nutrients through the stems.
To prepare the additive, dissolve 3 tablespoons of sugar and 2 tablespoons of white vinegar or lemon juice in 1 quart of warm water. Then, add 1/4 teaspoon of household bleach. Make sure to change the water and preservative solution every few days to maximize the shelf life.