Why does my peace lily have yellow lower leaves?

On a peace lily this is an older leaf, low on the plant and usually on the outside of the clump, turning yellow, often from the tip or the margin first and then across the blade. The leaves above it stay glossy and dark green.

The most likely cause is too much water, or a pot that stays wet. This is the one common houseplant that wants its compost lightly moist, so it is watered often, about every 5 days in the growing season and about every 8 in winter. That is exactly why it is easy to overdo. Water on the summer rhythm into a cold winter and the compost stays soaked, the roots lose their air, and the oldest leaves are the first to be given up. The entry says that yellow lower leaves in wet compost mean the roots are drowning, which is the one thing that will kill the plant.

To confirm it in a minute, push a finger into the compost to the second knuckle and lift the pot. Still wet and heavy days after watering, or a saucer with water standing in it, settles it. A sour smell at the surface or soft brown roots at the drainage holes points the same way.

Two other causes are worth ruling out. One old leaf at a time going yellow, while new leaves keep unrolling at the centre, is simply age. And a plant that collapses repeatedly from thirst loses roots each time, and the lower leaves follow. A peace lily that has filled its pot, with roots crowding the drainage holes, may also be hungry.

A yellow leaf will not turn green again, so judge the recovery by the next new leaf, which should come through clean once the roots are breathing again. Allow a few weeks in the growing season. If the roots have rotted, the plant needs longer, and winter slows it further.

What this plant wants

The fix

Let the top of the mix dry slightly between waterings; remove old leaves cleanly.

Read on

Yellow leaves at the bottom of the plant

The same sign on any plant, with the causes in the order they are likely.

Peace lily care

Light, water, feeding, repotting and the rest of the entry.

Check it in the diagnoser

Opens with the plant, the part and the sign already chosen.