The Pothos, or Epipremnum aureum, is a ubiquitous houseplant favored for its trailing vines and adaptability. Despite its reputation for hardiness, the sudden appearance of yellow leaves, a condition known as chlorosis, often signals a specific issue in the plant’s environment. This discoloration indicates the loss of chlorophyll, the green pigment necessary for photosynthesis. Identifying the precise stressor requires observing the pattern of the yellowing, the location of the affected leaves, and assessing the soil’s moisture level.
The Primary Cause: Water Imbalance
Improper watering is the most frequent reason Pothos leaves turn yellow, and the symptoms differ depending on whether the plant is over- or underwatered. Overwatering occurs when the soil remains saturated for too long, displacing the oxygen that roots need to respire. This lack of oxygen leads to root suffocation and decay, commonly called root rot, which ironically prevents the plant from taking up water and nutrients even when the soil is wet.
The physical signs of overwatering include yellowing of the lower, older leaves first, often accompanied by soft, limp stems and mushy leaves. The soil will feel consistently wet to the touch. In severe cases, the roots appear dark, slimy, and emit a foul odor, indicating root rot. To correct this, allow the plant to dry out completely. If root rot is extensive, trim the decayed sections before repotting into fresh, well-draining soil.
Conversely, an underwatered Pothos exhibits yellowing that may affect the entire leaf. These leaves often feel dry and crispy, sometimes with brown edges, and the plant may display dramatic wilting. The soil in an underwatered pot will be bone-dry and may even pull away from the sides of the container.
The solution for drought stress is a thorough deep soaking, allowing water to drain completely from the bottom of the pot, followed by establishing a more consistent watering schedule. When diagnosing, feel the soil two inches down; if it is completely dry, the issue is likely underwatering, but if it is wet days after the last watering, overwatering is the culprit.
Nutritional Deficiencies in Pothos
Yellowing leaves can also be a clear indication that the plant is lacking specific nutrients, a condition distinct from water-related stress. The location of the yellowing provides a direct clue as to which element is insufficient. Nitrogen, a mobile nutrient, is one of the most common deficiencies, manifesting as a uniform yellowing across the entire leaf blade, beginning with the older, lower leaves.
Because nitrogen is mobile, the plant pulls this element from older foliage to support new growth, causing the older leaves to fade. Providing a balanced, nitrogen-rich liquid fertilizer during the growing season is the most effective corrective action.
A different pattern of yellowing, called interveinal chlorosis, points toward a lack of immobile micronutrients like magnesium or iron. Interveinal chlorosis means the tissue between the leaf veins turns yellow while the veins themselves remain green. Iron deficiency typically appears on the newest leaves first, as the plant cannot relocate the nutrient from older growth.
Magnesium deficiency also causes interveinal chlorosis but is often seen on older leaves, sometimes with yellowing edges. Old, compacted soil can hinder nutrient uptake, even if fertilizer has been applied. Repotting into a fresh, porous potting mix can refresh the nutrient availability and structure of the growing medium.
Environmental Factors and Placement
When soil moisture and nutrient levels are optimal, yellowing can be caused by external environmental stressors. Pothos prefer bright, indirect light, and issues arise when the light is either too low or too intense. Insufficient light causes a general, uniform yellowing across the foliage as the plant struggles to produce chlorophyll. The plant may also become “leggy,” with long gaps between leaves, as it stretches to find light.
Conversely, exposure to too much direct sunlight, particularly harsh afternoon sun, can cause a form of leaf burn. This damage appears as bleached-out yellow patches or scorch marks, typically on the leaves facing the window. Moving the plant a few feet back from the window or using a sheer curtain to diffuse the light can prevent this sun damage.
Temperature fluctuations are another source of stress, especially cold drafts from windows or air conditioning vents. Pothos thrive in stable indoor temperatures, and sudden drops can cause leaves to yellow and drop quickly. Maintaining a consistent temperature between 60°F and 85°F minimizes environmental shock. Finally, a small amount of yellowing is natural: the oldest leaves at the base of the vine will occasionally yellow and drop as the plant sheds older foliage to conserve energy for new growth.