GrowingHQ

Peace lily: lower leaves turning yellow

3 causes GrowingHQ holds specifically for peace lily, what separates them, and what is safe to do before you are sure.

What you are looking at

The oldest leaves — those nearest the base — losing their green while the growing tip stays healthy. Extremely common on tomatoes and peppers, and one of the least specific signs in growing: at least four unrelated things produce it, and one of them is the plant behaving perfectly normally.

It may be nothing

One of the causes below is a normal process rather than a problem. Read that one first: treating a healthy plant does more harm than leaving an unhealthy one a day longer.

What it is likely to be on peace lily

  1. Normal leaf ageing

    May be normalcommon on this plant
    source

    Sourced guidancemoderate confidence

    • Royal Horticultural Society: Houseplant problems

    Checked 2026-08-13

    Not a problem, and included as a candidate because it is one of the commonest explanations for a single yellow leaf on an otherwise healthy plant. Every plant sheds its oldest leaves; a differential that cannot return 'nothing is wrong' will always find something to blame.

    Points towards it

    • · only the lowest, oldest leaf is involved and the rest of the plant looks well
    • · one leaf at a time, not a general decline
    • · nothing changed, which is what you would expect of an ordinary process

    Argues against it

    • · several leaves yellowing at once across the plant is not ageing — ageing takes one leaf at a time from the bottom — this rules it out entirely.

    Check this next

    Count how many leaves are affected and where they are. One lowest leaf yellowing on a plant that is otherwise growing well is what these plants do; three or more at once, or any yellowing higher up, is a problem.

    What to do now

    Remove the leaf when it comes away easily and change nothing else. This is the diagnosis most worth getting right on a houseplant, because the usual response — watering much less on suspicion of root rot — damages a plant that was perfectly healthy.

    source

    Sourced guidancemoderate confidence

    • Royal Horticultural Society: Houseplant problems

    Checked 2026-08-13

  2. Overwatering

    Candidate 2very common on this plant
    source

    Sourced guidancehigh confidence

    • Royal Horticultural Society: Overwatering

    Checked 2026-08-13

    Not a matter of volume but of frequency: roots need air as well as water, and compost that never dries suffocates them. It kills more houseplants than every pest and disease combined, and its cruellest feature is that the early signs — yellowing, wilting, dropping leaves — look exactly like drought, so the instinct is to water more.

    Points towards it

    • · the compost is wet and the plant is yellowing anyway
    • · saucers and cachepots left full are the commonest cause
    • · roots short of air affect the whole plant rather than one old leaf

    Argues against it

    • · the compost is dry, so the roots are not short of air — this rules it out entirely.
    • · a single lowest leaf yellowing on an otherwise healthy plant is ordinary ageing rather than waterlogging

    Check this next

    Count the yellow leaves and feel the compost at depth. One lowest leaf on a plant that is otherwise growing well is normal ageing; several at once with wet compost is waterlogging, and the next step is to tip the plant out and look at the roots rather than to feed it.

    What to do now

    Empty the saucer or cachepot and stop watering until the top few centimetres are dry. Do not feed a yellowing plant in wet compost — the roots cannot take up what is already there, and feeding adds salts to a root system that is already struggling.

    source

    Sourced guidancehigh confidence

    • Royal Horticultural Society: Overwatering — recovery

    Checked 2026-08-13

  3. Underwatering

    Candidate 3common on this plant
    source

    Sourced guidancemoderate confidence

    • Royal Horticultural Society: Watering houseplants

    Checked 2026-08-13

    Easier to correct than overwatering and easily confused with it, because a plant short of water and a plant drowning both wilt. The distinguishing observation is not the plant at all — it is the compost, and it takes two seconds to check.

    Points towards it

    • · the drought that caused it has usually already been corrected, so nothing appears to have changed at the moment the leaves go yellow
    • · the oldest and outermost leaves are the ones that collapse furthest and the ones that do not come back
    • · a peace lily is grown indoors

    Argues against it

    • · every leaf yellowing together points at the roots rather than at damage a few leaves took during one dry spell
    • · a recent repot supplies a much better explanation for a general check than an earlier drying out

    Check this next

    Ask whether this plant has ever been allowed to go completely flat and then been rescued. A peace lily that wilted hard and stood back up will yellow off its outermost leaves for two or three weeks afterwards while the rest of it grows normally — that is scar tissue from the drought, not a new problem, and the compost being moist NOW is the strongest evidence for it rather than against it.

    What to do now

    Cut the yellowed leaves off at the base and keep watering as normal — they will not green up again and the plant is not asking for anything. Then water before it wilts rather than because it has: a peace lily that is allowed to collapse repeatedly loses a ring of outer leaves each time and slowly becomes a smaller plant.

    source

    Sourced guidancemoderate confidence

    • Royal Horticultural Society: Houseplants — watering and feeding

    Checked 2026-08-13

Narrow it down

This page lists everything at once, which is the right shape for reading and the wrong shape for deciding. The interactive tool asks one question at a time, starting with whichever would separate these causes fastest, and stops as soon as further answers would not help.

Work through it for your peace lily

Opens with the plant and the symptom already set. Nothing you answer is stored or sent anywhere — the answers live in the address bar and nowhere else.

What this does not cover

These are the causes GrowingHQ holds rules for on peace lily — not every cause there is. Where several problems look alike, the honest answer is often that they cannot be told apart by eye, and a page that named one would be guessing. If none of the above fits, the general lower leaves turning yellow page lists causes across all plants, and the Peace lily profile lists the problems it is prone to.