Most likely cause

Overwatering is the top cause of yellow Pothos leaves. Pothos evolved to handle dry spells and have roots that need air, so they are far more sensitive to soggy soil than to drought. Kept constantly wet, the roots cannot breathe, they begin to rot, and they stop feeding the foliage.

You can confirm it by the pattern. Overwatering yellows the lower, older leaves first, the leaves feel soft and limp rather than crispy, and the soil stays wet for days. A pot with no drainage hole, or watering on a fixed schedule regardless of dryness, makes it almost certain. Let the soil dry to the top 1 to 2 inches before watering and the yellowing should stop spreading.

Other causes

These rank below overwatering but are common with Pothos.

  • Too little light. In dim corners the plant cannot feed itself and drops older leaves; variegated types also fade, losing their cream or gold and reverting to plain green.
  • Natural aging. A single oldest leaf at the base of a vine yellowing slowly is normal, while the rest of the vine and new growth look healthy.
  • Underwatering. Long droughts make the plant shed leaves; the soil is bone dry and yellowing may come with crispy edges and limp, thin vines.
  • Nutrient deficiency. Long-unfed or root-bound plants in old soil pale to an even yellow across many leaves, with smaller new growth.

How to fix it

  1. Check the soil. Feel the top 1 to 2 inches. If it is still wet, wait until it dries before watering again.
  2. Confirm drainage. Use a pot with a drainage hole and empty any saucer so the roots never sit in standing water.
  3. Water only when dry. Let the top 1 to 2 inches dry out, then soak until water runs from the bottom. Pothos prefer this drench-and-dry rhythm.
  4. Improve the light. Move it to medium to bright indirect light to keep variegation strong and growth steady.
  5. Pinch off yellow leaves. Remove fully yellow leaves at the node with clean shears to redirect energy and encourage branching.
  6. Feed in the growing season. Through spring and summer feed a balanced fertilizer at half strength every few weeks if the soil is old.
  7. Check the roots if it spreads. If many leaves yellow and the soil smells sour, unpot, trim any mushy roots, and repot in fresh, well-draining mix.
CauseTell-tale signFix
OverwateringSoft lower leaves, wet soilLet top 1 to 2 inches dry, ensure drainage
Too little lightFaded variegation, leggy vinesMove to medium-bright indirect light
Natural agingSingle oldest leaf on a vinePinch it off, no action needed
UnderwateringBone-dry soil, limp crispy leavesWater thoroughly, water more regularly
Nutrient deficiencyEven pale yellowing, small new growthFeed at half strength, repot if root-bound