The Pothos plant, Epipremnum aureum, is a common and resilient houseplant known for its cascading foliage and ability to tolerate a wide range of indoor conditions. Many owners observe small, clear droplets of water forming on the tips of the leaves, especially in the morning. This phenomenon, which can make the plant appear to be “crying,” is a natural physiological process that signals the plant is actively managing its internal water balance. While it may look alarming, the dripping water is usually an indication that the plant is healthy and its systems are working efficiently to handle an abundance of moisture.
What Is That Dripping Water?
The droplets observed on the Pothos leaves are not simple condensation but are a result of a process called guttation. This term describes the plant actively secreting liquid water from its leaves, primarily along the margins or tips. The liquid is not pure water but is a thin, watery solution known as xylem sap. This sap contains water and various trace solutes, including sugars, mineral salts, and organic compounds absorbed from the soil. When this liquid dries, it may leave a slight, crusty white residue on the leaf surface, which is the mineral content that was expelled. Frequent or heavy occurrence indicates that the plant is experiencing a surplus of water in its system.
The Science Behind Guttation
Guttation is driven by a mechanism known as “root pressure,” which occurs when the plant’s roots continue to absorb water from the soil even when the rate of water loss from the leaves is low. During the day, plants lose water vapor through a process called transpiration, driven by the opening of tiny pores called stomata on the leaf surface. This loss of water creates a negative pressure, or “pull,” that draws water and nutrients up from the roots. At night, or when the air is highly saturated with moisture, the stomata close to conserve water, effectively halting transpiration.
However, the roots continue to absorb water and dissolved minerals, causing water pressure to build up inside the plant’s vascular system. This positive internal pressure pushes the excess xylem sap upward and outward through specialized structures called hydathodes. Hydathodes are small, specialized openings located at the leaf tips, unlike the regulated stomata. The pressurized sap is forced out through these hydathodes as liquid droplets, allowing the plant to relieve the internal hydrostatic pressure. This mechanism helps the plant regulate its hydration status when transpiration is suppressed.
Adjusting Care to Stop the Dripping
The presence of frequent guttation is a clear signal that the Pothos has absorbed more water than it can evaporate, requiring adjustments to the plant’s environment and care routine. The primary focus should be on controlling the moisture level in the soil and the air surrounding the plant.
Always check the soil moisture before watering, using a finger or moisture meter to confirm the soil is dry a few inches deep. Allowing the top one to two inches of soil to dry out completely between waterings reduces the total water available for root absorption. This prevents the excessive buildup of root pressure that triggers the guttation response.
It is also important to ensure the pot has adequate drainage holes and to avoid letting it sit in standing water. Poor drainage leads to perpetually saturated soil, which forces the roots to continuously absorb water and exacerbates the dripping.
High humidity or poor air circulation can also suppress transpiration rates, making the problem worse. Improving airflow around the Pothos by opening a window or using a small fan encourages water vapor to leave the leaves, restoring the transpiration process. If the plant is frequently dripping, slightly reducing the watering frequency and ensuring good air movement are the most effective steps. Furthermore, temporarily reducing fertilizer application can prevent salt buildup on the leaf tips if the droplets contain a heavy mineral concentration.