What is the purpose of using citric acid as a pre-treatment for some cut flowers?

Using citric acid as a pre-treatment for cut flowers primarily serves to adjust the acidity of the stem, which helps improve water uptake. Many cut flowers benefit from a slightly acidic environment, which enhances the ability of the stems to absorb water effectively. This is crucial for prolonging the vase life of the flowers, as adequate hydration is essential for maintaining their firmness, color, and overall appearance.

In addition to adjusting acidity, citric acid can also help prevent the proliferation of bacteria in the water, further promoting water flow through the vascular system of the plant. This is important because bacteria can block the stems’ vessels, leading to decreased water availability and wilting.

The other options do not accurately describe the role of citric acid in this context. For example, citric acid does not remove toxins from the water directly, nor does it increase the sugar content of the flowers. While it may have some effect on color due to overall health improvements, enhancing flower color is not its primary purpose as a pre-treatment.