Using tap water for cut flowers is generally acceptable, though it is not the most optimal choice for maximizing their vase life. Tap water provides the basic hydration necessary for the flowers to survive, but it often lacks the specific properties and additives that promote long-lasting freshness. For the best results, simple preparations and the addition of specialized flower food are necessary to counteract the inherent limitations of standard tap water.
Understanding the Components of Tap Water
Tap water contains various dissolved substances that can negatively affect the delicate vascular system of cut flowers. One common component is chlorine, which is added as a disinfectant to inhibit bacterial growth in the water supply. Although chlorine is a biocide, it can also damage the freshly cut tissues of the flower stems, sometimes causing mild stress to the plant cells.
Another factor is the presence of dissolved minerals and salts, which contribute to water hardness. High concentrations of minerals like calcium and magnesium can accumulate in the water-conducting tissues of the stem, known as the xylem. This mineral buildup physically blocks the pathways, impeding the flower’s ability to draw water up to the petals and leaves, a phenomenon called vascular blockage.
Furthermore, tap water’s pH level typically ranges from 5 to 8. This is often higher than the slightly acidic range of 3.5 to 5.0 that cut flowers prefer for optimal water uptake.
Simple Preparations to Improve Water Quality
Before placing flowers in a vase, simple steps can be taken to mitigate some of the less desirable characteristics of tap water. If your local water supply uses chlorine, letting the water sit in an open container for 12 to 24 hours allows the free chlorine to dissipate into the air. This process, however, is not effective at removing chloramine, a more stable disinfectant used in some areas, or the dissolved mineral content.
Using lukewarm water, rather than cold water, can also improve initial hydration. Warmer water molecules move more quickly and are more readily absorbed by the stem, helping to re-establish the water column. Beyond treating the water itself, ensuring the vase is completely clean is a fundamental step, as residual bacteria or organic matter can quickly contaminate the fresh water and hasten stem blockage.
The Necessity of Flower Food
Even after simple preparations, tap water remains insufficient because it lacks the necessary ingredients to provide sustained energy and a clean environment for the flower. Commercial flower food packets contain a carefully balanced mixture of three primary components that address the flower’s post-harvest needs: a sugar source, a biocide, and an acidifier.
The sugar, typically a carbohydrate, serves as a nutrient source, providing the energy the flower needs to maintain its color, scent, and turgidity. The biocide, an antibacterial agent, is included to prevent the rapid growth of microorganisms in the vase water, which are the main cause of vascular blockage in the stem. Finally, an acidifier is added to lower the water’s pH, creating the slightly acidic environment that promotes efficient water uptake by the cut stem.