When flowers are cut, they are separated from their root system, causing them to begin senescence, or aging. Cut flower food is a specially formulated additive designed to slow this natural process and extend the freshness and vibrancy of a floral arrangement. This preservative addresses three primary challenges: a lack of energy, poor water uptake, and the rapid growth of microorganisms. Using a prepared solution helps blooms continue to open, maintain their color, and resist wilting longer than if they were placed in plain water.
The Three Core Ingredients
Commercially produced flower foods contain three functional components that work together to maximize the life of the blooms. The first component is a nutrient source, typically a carbohydrate like sucrose or common table sugar. This ingredient replaces the energy the flower can no longer produce through photosynthesis after being cut. The second component is a vascular flow enhancer, usually an acidifier such as citric acid, which adjusts the pH level of the vase water to a more acidic range. The third element is a microbial inhibitor, or biocide, included to control the growth of bacteria and fungi. Common biocides include chlorine-based agents like sodium hypochlorite (bleach) or various quaternary ammonium compounds.
How Each Component Extends Flower Life
Nutrient Source
The nutrient source (sugar) provides fuel for the flower’s metabolic processes, including respiration. This energy allows flowers to maintain turgor pressure, the internal water pressure that keeps petals and stems firm and upright, delaying wilting. Supplying carbohydrates also supports the continued development and opening of buds cut before they fully bloomed.
Acidifier
The acidifier creates a slightly acidic environment, improving the flower’s ability to absorb water. Most cut flowers absorb water efficiently when the pH is between 3.0 and 5.0. By reducing the water’s pH, the acidifier prevents the plant’s natural defense response to stress, which is forming blockages in the xylem vessels (the main water-conducting tubes in the stem).
Biocide
The biocide addresses stem blockage, the most common cause of premature wilting. Bacteria and fungi proliferate quickly in vase water, forming a slimy film that physically clogs the cut ends of the stems. This microbial growth is accelerated by the sugar added to feed the flowers. The biocide inhibits these microorganisms, keeping the water clean and ensuring the water-conducting tissues in the stem remain open for continuous hydration.
Making Your Own Flower Food
It is possible to create an effective holding solution at home using common staples that replicate the three core functions of commercial flower food. White granulated sugar provides the energy source, typically one tablespoon per quart of water, supporting cell function. To act as the acidifier, a small amount of lemon juice, lime juice, or white vinegar can be added to lower the water’s pH, which helps the stem take up water more easily and prevents wilting. For the biocide, a few drops of regular household bleach prevent bacterial growth and keep the water clear. A common recipe mixes one tablespoon of sugar, two tablespoons of lemon juice, and a quarter teaspoon of bleach into one quart of water.