Caring for an arrangement of cut flowers properly can lengthen the attractive life of the flowers by days or weeks. One aspect of proper cut flower maintenance involves the judicious use of a commercially available or homemade flora preservative. One key ingredient in an effective floral preservative is sucrose, a type of sugar.
Sugar and Cut Flower Life
While still attached to a plant, the flower benefits from the sugars that the plant's leaves manufacture through the process of photosynthesis. Once the flower is cut from the plant, the number of leaves providing food is greatly limited, as is the amount of light available for food production. As a result, the amount of food available to the flower is drastically reduced. To make up for this loss, sucrose is added to the water the flower stems are placed into to ensure the continued development of the flower and greater longevity.
Other Ingredients in Floral Preservatives
While a sugar solution essentially "feeds" the cut flowers, it also encourages the growth of bacteria, which makes the water appear cloudy and smell bad and interrupts the stem's uptake of water. To combat bacterial and fungal growth, a microorganism growth inhibitor is added to the solution. An acidifier lowers the pH of the water so is closer to the pH of the plant sap and stabilizes the color of the flower. Commercially available preservatives may also contain a respiratory inhibitor.
Amount of Sugar to Use
Instructions for mixing the preservative with water are included with store-bought floral preservatives. However, if making a homemade floral preservative, using an appropriate amount of each type of ingredient is necessary to achieve the intended results. One recipe for floral preservative calls for 2 teaspoons sugar, 1/2 teaspoon chlorine bleach and 1/2 teaspoon alum per quart of water. Another option is to use 2 tablespoons white vinegar, 2 teaspoons sugar, 1/2 teaspoon bleach and a quart of water. An additional floral preservative recipe calls for 1 pint non-cola, non-diet soda, 1/2 teaspoon bleach and 1 pint water.
Further Prolonging Cut Flower Life
The cut ends of flowers should be placed in water immediately after removing them from the plant. Cut the stems at an angle so that greater surface area is available for the uptake of water. Any leaves below the waterline should be removed from the flower stems, and the lowest 1/2 to 1 inch of stem should be trimmed off every few days. Add new water to the cut flower container as needed to replace water that evaporates. Whenever the water becomes cloudy, an indication of bacterial activity, dump it out and replace with fresh water and preservative. Keeping flowers in a cool area away from drafts, heat sources and apples (which produce ethylene gas that speeds ripening and rotting) will further increase flower arrangement longevity.
Your Planting Articles
- University of Massachusetts Amherst: Sugar and Acidity in Preservative Solutions for Field-Grown Cut Flowers
- Purdue University Cooperative Extension Service: Add Hours to Your Flowers
- University of Minnesota Extension: Keeping Cut Flowers and Flowering Plants
- Oklahoma Cooperative Extension Service: The Care and Handling of Cut Flowers
- University of Illinois Extension: Care of Cut Flowers and Foliage
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