The Pothos plant (Epipremnum aureum) is a popular and resilient houseplant known for its trailing vines. Even this hardy species can show distress, most commonly through the yellowing of its leaves, a process called chlorosis. This discoloration signals that the plant’s environment or care routine needs adjustment. Understanding the pattern and location of the yellowing is the first step toward diagnosing and fixing the underlying issue.
Watering Imbalances: The Most Common Culprit
The most frequent cause of yellowing Pothos leaves relates directly to soil moisture levels, which can be too high or too low. Overwatering is common, causing the soil to remain saturated and displacing the oxygen roots need for respiration. When roots are deprived of oxygen, they decay, a condition known as root rot. Root rot prevents the plant from absorbing water and nutrients, resulting in soft, mushy, yellow leaves, often on the older, lower parts of the plant.
Conversely, allowing the soil to become excessively dry also causes leaf yellowing. Underwatering triggers a drought-stress response, where the Pothos redirects moisture and nutrients from older leaves to sustain new growth. Symptoms manifest as dry, crispy yellow leaves, often starting at the edges and tips. The plant may also appear wilted, with leaves feeling dry and brittle.
To differentiate, check the soil by inserting a finger one to two inches deep. Overwatered soil feels consistently wet or soggy days after watering, while underwatered soil feels bone dry. Proper drainage is also a factor; a pot without drainage holes or heavy soil can cause overwatering. The key is to allow the top inch or two of soil to dry out completely before administering a thorough watering.
Light and Temperature Stress
The Pothos’s environment plays a significant role in maintaining chlorophyll within its leaves. Insufficient light causes the plant to struggle to produce enough energy through photosynthesis to support all its foliage. This lack of energy results in a general, uniform yellowing and fading of the leaves, often leading to leaf drop as the plant sacrifices older growth.
Too much light, specifically direct, intense sunlight, can be equally damaging. Pothos are not adapted to withstand harsh, direct rays, as they are native to the forest understory. Exposure to unfiltered sun, particularly from a south-facing window, can scorch the foliage. This leads to bleached, pale yellow, or white patches that resemble sunburn, which may eventually turn brown and crispy.
Temperature fluctuations also introduce stress that results in leaf yellowing and dropping. Pothos prefer a stable indoor temperature, generally between 65°F and 85°F. Placing a plant near a drafty window, an air conditioning vent, or a heat source can cause sudden temperature shifts that shock the plant. This environmental stress triggers a reaction where the plant sheds its leaves, which first turn yellow.
Underlying Issues: Nutrient Deficiencies and Root Health
Beyond environmental factors, the health of the root system and soil nutrient balance contribute to chlorosis. While Pothos are not heavy feeders, a deficiency in specific nutrients can halt chlorophyll production. A lack of nitrogen, essential for growth, causes generalized yellowing that begins with older, lower leaves as the plant mobilizes limited nitrogen to new growth.
Other deficiencies present with distinct patterns, such as interveinal chlorosis caused by a lack of magnesium or iron. In this scenario, the tissue between the leaf veins turns yellow while the veins remain green. Iron deficiency usually affects the youngest leaves first, while magnesium deficiency appears on older leaves. These issues are common in plants that have been in the same pot for several years without being fertilized.
The physical constraints of the container can also impede the plant’s ability to thrive, leading to yellowing. If a Pothos is left in the same pot too long, its roots can become rootbound, circling tightly inside the container. A constricted root ball struggles to absorb water and nutrients effectively, even if the soil is moist and fertilized. This restriction causes a decline in health and subsequent yellowing, signaling the need for a slightly larger pot.
Corrective Measures and Prevention
Once a Pothos leaf has turned completely yellow, it will not revert to green because the chlorophyll is permanently degraded. Pruning these damaged leaves allows the plant to redirect energy toward new, healthy growth. Use clean, sharp scissors to remove the yellowed foliage near the main vine.
To address moisture imbalances, establish a routine of testing the soil before watering. Use the finger test or a moisture meter to ensure the top two inches of soil are dry. Always ensure the pot has drainage holes to avoid waterlogging. If root rot is suspected, gently remove the plant, trim any dark, mushy roots, and repot it into fresh, well-draining soil.
Correcting light and nutrient issues involves repositioning the plant and introducing a balanced feeding schedule. Move plants exhibiting sunburn away from direct sun exposure to a spot that receives bright, indirect light, such as near a north or east-facing window. During the spring and summer growing seasons, apply a balanced, diluted liquid fertilizer once a month to prevent nutrient deficiencies. Consistency in monitoring soil moisture, light exposure, and temperature provides a stable environment and prevents future episodes of chlorosis.