Why are my Peace Lily leaves turning yellow?

Let the colour pattern tell you the cause

Yellow is the least specific symptom a Peace Lily gives you, because nearly every problem ends in yellowing once the roots or leaves stop working. The trick is to read three things together: which leaves are affected, how the leaf feels, and what the soil is doing. Overwatering yellows the lower leaves first and they feel soft and limp. Aging affects only the single oldest leaf at the very bottom. Underwatering yellows leaves that feel dry and crispy at the edges with bone-dry soil. Nutrient deficiency pales many leaves at once to an even, uniform yellow. Sorting by pattern, rather than reacting to the colour alone, is what keeps you from watering a plant that is already drowning.

Overwatering: the most likely cause

Overwatering is the top cause of yellow Peace Lily leaves. They like steady, light moisture but cannot sit in saturated soil; roots deprived of air begin to rot and can no longer feed the leaves, which fade to yellow, usually starting with the lower foliage. The Missouri Botanical Garden notes that the early symptoms of overwatering can look just like underwatering, which is why feeling the soil matters more than reacting to the leaf.

You can confirm overwatering by the pattern. The yellow leaves feel soft rather than crispy, the soil stays wet for days, and the pot feels heavy. If there is no drainage or the plant sits in a full saucer, this is almost certainly the driver, and you will often see drooping at the same time. Let the soil dry to the top inch, improve drainage, and the yellowing should stop spreading to new leaves.

Other causes

These rank below overwatering but often overlap with it.

• Natural aging. A single old lower leaf yellowing slowly is normal; only the bottommost leaf is affected while the rest of the plant looks healthy and firm.
• Underwatering. Prolonged dry soil stresses the roots; the soil is bone dry and light, and yellowing often comes with wilting and crispy edges.
• Too much direct sun. Harsh light bleaches the foliage; look for pale yellow patches on the leaves facing a south or west window.
• Nutrient deficiency. Old, spent soil runs short on feed; the whole plant pales to an even yellow across many leaves at once.

A worked example

Three of the lower leaves on your Peace Lily have turned a soft yellow over the past week, and the plant has started to droop a little even though you watered it three days ago. You lift the pot and it feels heavy, and the soil at the top is still damp. That set of clues, multiple lower leaves yellowing soft, recent watering, heavy pot, damp surface, points firmly at overwatering rather than thirst or aging. The wrong move here is to water again because of the droop. The right move is to stop watering, check the drainage hole is clear, and if the soil stays soggy for several more days, unpot and look for brown mushy roots.

How to fix it

1. Check the soil. Feel the top inch. If it is wet, hold off watering until it dries out, and lift the pot to gauge how heavy it is.
2. Improve drainage. Make sure the pot drains freely and empty any saucer so the roots never sit in standing water.
3. Water consistently. Water only when the top inch is dry, then let the pot drain fully, using room-temperature filtered water.
4. Remove spent leaves. Cut fully yellow leaves at the base with clean scissors to tidy the plant and redirect energy to healthy growth.
5. Adjust the light. Move the plant to bright indirect light, out of direct sun that can bleach the leaves.
6. Refresh feeding. During the growing season, feed at quarter to half strength every 6 to 8 weeks, or repot if the soil is old and spent.