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Peace lily brown leaf tips and edges: causes and what to do

6 results in the diagnosis tree begin with brown tips and edges, 3 of them marked likely when the answers fit. They are ordered here for Peace lily (Spathiphyllum wallisii), using what its sources say about humidity, soil moisture, cold tolerance, watering and feeding and one problem recorded for it.

Sources last read 14 September 2026.

Start the diagnosis for this Peace lily

Peace lily (Spathiphyllum wallisii), the whole plant.
Bernard DUPONT from FRANCE, CC BY-SA 2.0 · Wikimedia Commons

Spathiphyllum wallisii, commonly known as peace lily, white sails, or spathe flower, is a very popular indoor house plant of the family Araceae. The genus name means "spathe-leaf", and the specific epithet is named after Gustav Wallis, the German plant collector. Wikipedia, CC BY-SA 4.0

Native range: Colombia to Venezuela (wet tropical). Also sold as Spathe Flower and white sails.

What Peace lily’s sources say that bears on this

Humidity
ASHRAE recommends indoor relative humidity between 30% and 60%
Penn State Extension · read 11 September 2026
Soil moisture
Moist but well-drained
RHS · read 11 September 2026
Cold tolerance
H1B — 10–15°C
RHS · read 11 September 2026
Watering
Keep the soil moist without letting it get soggy, and let it dry between waterings. Peace lilies respond well to bottom watering.
NC State Extension · read 13 September 2026
While growing, water and mist generously and keep humidity high.
RHS · read 13 September 2026
Feeding
Feed at a quarter of the label strength, and flush the soil between feeds. Too much fertilizer and a build-up of salts can burn roots and leaf tips.
NC State Extension · read 13 September 2026
Feed monthly with a balanced liquid fertiliser.
RHS · read 13 September 2026

How this shows up on a Peace lily

Brown tips on the newest leaves first

Leaves on the side of the peace lily nearest a heater or vent brown at the edges while those on the far side stay clean.

Penn State Extension cites ASHRAE's recommended indoor range of 30% to 60% relative humidity; a heated room in winter drops below it. Air that dry pulls water from the leaf faster than the roots replace it, and the margins are furthest from the supply.

Telling it apart: Where the plant stands. Browning concentrated on the side facing a heater points at the air.

Penn State Extension · read 11 September 2026

Possible causes, likeliest first for a Peace lily

  1. Most likely cold

    Ranked higher because Peace lily's recorded problems point this way.

    Its RHS hardiness rating puts this plant's cold floor at 10°C or above, so a cold windowsill at night is a strong explanation.

    • H1B — 10–15°C RHS · read 11 September 2026

    Why: Soft, dark patches rather than crisp ones are damaged tissue rather than dried tissue.

    What to try:

    • Move it away from the glass at night, or keep the curtain on the room side of the peace lily.
    • Leave damaged leaves until new growth appears, then remove the worst of them.

    What would settle it: Where the peace lily sits at night, and what the glass feels like at that hour. Damage that appeared after one cold night, on the side facing the window, is the pattern.

    Check this with the questions

  2. Most likely too little water

    Ranked higher because Peace lily's recorded problems point this way.

    • Moist but well-drained RHS · read 11 September 2026

    Why: Soil dry two inches down leaves the roots nothing to send up, and the leaf edges are the last tissue in line.

    What to try:

    • Water thoroughly, until it runs from the drainage hole.Useful: pot with drainage holes
    • Check the soil with a finger every few days rather than watering on a fixed day.Useful: moisture meter

    What would settle it: Water it thoroughly and watch the next new leaves. If they come in with clean edges under steadier watering, the edges were thirst.

    Check this with the questions

  3. Most likely a build-up of salts in the soil

    • Chalk, Loam, Sand; pH Acid or Alkaline or Neutral RHS · read 11 September 2026

    Why: Minerals from tap water and fertiliser are left behind as water evaporates, and a white crust on the compost or the pot rim is where they show.

    What to try:

    • Water slowly and heavily until several times the pot's volume has run through the drainage hole, to wash the salts out.Useful: pot with drainage holes
    • Scrape off the top layer of crusted compost and replace it.

    What would settle it: Scrape the crust. If it is gritty and dissolves in water it is mineral; if it is fluffy it is mould, which is a different problem.

    Check this with the questions

Less likely for a Peace lily, still possible

Questions

What usually causes brown tips and edges on a Peace lily?
For Peace lily: most likely cold, most likely too little water and most likely a build-up of salts in the soil. Its RHS hardiness rating puts this plant's cold floor at 10°C or above, so a cold windowsill at night is a strong explanation.
How can I tell which one it is on my Peace lily?
Is the browning crisp and dry, or soft and dark? Crisp and dry; Soft and dark.
What do Peace lily's sources say about its soil moisture?
RHS: Moist but well-drained.
What does this look like on a Peace lily?
Leaves on the side of the peace lily nearest a heater or vent brown at the edges while those on the far side stay clean. Telling it apart: Where the plant stands. Browning concentrated on the side facing a heater points at the air.
Is Peace lily safe to handle while I check it?
Its sources list it as toxic to cats, dogs and people. Wash your hands after handling the roots or sap, and keep trimmings away from pets.

Something else wrong with the Peace lily?

Everything the sources say about Peace lily

What this does not cover

This page orders a decision tree's results using a plant's sourced care. It has not seen your plant, its pot or its window, and two problems at once are common: that is the usual reason a confident answer turns out wrong. The questions in the diagnosis tool narrow it further than a list can.