What causes clogged stems in cut flowers?

Clogged stems in cut flowers primarily occur due to air embolism, which is the phenomenon where air bubbles form and block the xylem vessels responsible for transporting water and nutrients from the roots through the stem to the petals and leaves. When flowers are cut, they can experience exposure to air, leading to the formation of these air bubbles. Once these bubbles enter the vascular system of the plant, they block the pathway that is essential for water uptake, resulting in wilting and reduced longevity of the flowers.

Addressing the other options, while a lack of water can certainly lead to wilting, it does not directly cause blockage within the stem’s vascular tissue. Excess nutrients can affect the overall health of the plant but are less likely to cause stem clogging. Fungal infections can lead to other issues, such as decay or disease, but they do not specifically result in the air obstruction characteristic of an air embolism. Understanding the mechanics of air exchange and transport in plants highlights the significance of managing cut flowers to minimize air exposure, thus preventing air embolisms and ensuring optimal hydration and health.