The small sachet of powder included with a bouquet of cut flowers is a scientifically formulated floral preservative, commonly referred to as flower food. Its purpose is to extend the life and appearance of the blooms after being separated from their root system. Cut flowers require a specific balance of hydration and nourishment to counteract wilting and decay. Using this packet, rather than plain water, gives the flowers the resources necessary to maintain their color and structure for a longer period.
What the Flower Food Contains
The efficacy of the floral preservative packet comes from a precise mixture of three main chemical components, each serving a distinct biological function.
The first component is a carbohydrate source, typically a form of sugar like sucrose, which acts as the flower’s primary source of energy. Since a cut flower can no longer generate sufficient food, the sugar provides the necessary fuel for cell maintenance and the opening of buds. This supplemental feeding helps the blooms fully develop.
The second component is an acidifier, often citric acid, which regulates the pH level of the vase water. Tap water is frequently alkaline, which impedes the flower’s ability to absorb water efficiently. By lowering the water’s pH to a slightly acidic range, the acidifier mimics the natural pH of the plant’s sap. This makes the water easier for the xylem—the plant’s vascular tissue—to take up, improving hydration and preventing immediate wilting.
Finally, a biocide, usually a mild concentration of household bleach (sodium hypochlorite), is included to prevent the proliferation of microorganisms. The sugar added to feed the flowers encourages the growth of bacteria, fungi, and yeasts in the vase water. These microbes quickly clog the cut ends of the stems, blocking the water-conducting vessels. The biocide keeps the water clean and the stem ends unobstructed, ensuring a continuous flow of the solution into the flower.
Simple Steps for Using the Packet
Starting with a thoroughly clean vase is the first step, as any residue can introduce bacteria. Before placing the flowers into the solution, remove any leaves that would fall below the water line. Submerged foliage decays rapidly and accelerates the growth of harmful microbes. The stems should also be trimmed by about an inch at a 45-degree angle to create a fresh surface for water absorption.
To ensure the mixture is correctly balanced, always dissolve the entire packet in the exact volume of water specified on the packaging. Using too little water creates a solution that is too concentrated, which can damage the flower cells. Using too much water dilutes the ingredients and renders them ineffective. Lukewarm water is recommended for the initial hydration, as the slight warmth helps to soften any air bubbles or blockages in the stem’s vascular system.
For maximum longevity, the water should be completely replaced with a fresh mixture of water and a new packet of flower food every two to three days. Simply topping off the vase is not sufficient, as the biocide breaks down over time, allowing bacteria to accumulate. Changing the water also provides an opportunity to rinse the vase and recut the stems, ensuring the flowers are consistently receiving a fresh, clean drink.