The Pothos plant (Epipremnum aureum) is a popular houseplant appreciated for its trailing vines and resilience. When the normally deep-green foliage turns pale or lime-green, it signals environmental stress called chlorosis. This discoloration indicates the plant is struggling to produce sufficient chlorophyll, the pigment responsible for its green color and photosynthesis. Understanding this symptom helps diagnose and correct the underlying issue, which is generally related to light, nutrition, or water management.
Excessive Light Exposure
A common reason for Pothos leaves turning light green is overexposure to intense light. While Pothos thrives in bright, indirect light, direct sun is too strong for this tropical understory plant. When subjected to direct sunlight, the leaves reduce chlorophyll production to protect themselves from damage.
The resulting loss of pigment causes the leaves to appear bleached, faded, or pale green. This light stress can quickly lead to leaf scorch if the intense light continues. Immediately move the plant to a location where it receives bright, filtered light, such as near a north or east-facing window. This adjustment allows the plant to resume normal chlorophyll production and regain its deep green hue over time.
Nutritional Deficiencies
A lack of specific nutrients can directly impair the plant’s ability to create chlorophyll, leading to chlorosis. The pattern of the light green discoloration helps pinpoint the exact missing element. Nitrogen, a macronutrient, is a building block of chlorophyll and is mobile within the plant, meaning it moves from older leaves to support new growth.
Consequently, nitrogen deficiency first appears as uniform paleness or yellowing across the plant’s older, lower leaves. Other nutrients, such as magnesium and iron, are crucial for chlorophyll synthesis, but their deficiencies present differently. Magnesium or iron deficiencies cause interveinal chlorosis, where the tissue between the leaf veins turns light green or yellow while the veins remain dark green. Magnesium deficiency affects older leaves first, while iron deficiency is visible on the newer, upper leaves because iron is immobile.
Addressing these issues requires using a balanced houseplant fertilizer containing both macro and micronutrients. Fertilizing every two to four weeks during the growing season, diluted to half-strength, replenishes the soil and reverses the discoloration.
Addressing Water and Root Issues
The most frequent cause of pale leaves not related to light or fertilizer is improper watering, especially overwatering. Pothos roots require oxygen, and continuously saturated soil displaces the air, causing the roots to suffocate and die, a condition known as root rot. Damaged roots cannot efficiently absorb water or nutrients, causing the plant to display symptoms identical to a nutrient deficiency. The leaves turn light green or yellow because the plant cannot transport the necessary elements for chlorophyll production, even if those nutrients are present in the soil.
To diagnose a water problem, check the soil moisture by inserting a finger a couple of inches deep; if it is still wet, you are likely overwatering. If root rot is suspected, gently remove the plant and inspect the roots, which will appear soft, dark brown, or black and possibly have a foul odor, instead of their healthy light-tan or white color. Remedial action involves allowing the soil to dry out completely between waterings and ensuring the pot has adequate drainage holes. For severe root rot, trim away the damaged, mushy roots before repotting the plant into fresh, well-draining soil.