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Moth orchid 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 Moth orchid (Phalaenopsis), 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 Moth orchid

Moth orchid (Phalaenopsis), the whole plant.
Julian Herzog ( Website ), CC BY 4.0 · Wikimedia Commons

Phalaenopsis, also known as moth orchids, is a genus of about seventy species of plants in the family Orchidaceae. Orchids in this genus are monopodial epiphytes or lithophytes with long, coarse roots, short, leafy stems and long-lasting, flat flowers arranged in a flowering stem that often branches near the end. Wikipedia, CC BY-SA 4.0

Native range: Tropical & Subtropical Asia, NE. Australia. Also sold as Moon Orchid, Moon Orchids, Moth Orchids, moth plant, Phalaenopsis Orchid and Phalaenopsis Orchids.

What Moth orchid’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
Well-drained
RHS · read 11 September 2026
Cold tolerance
H1A — warmer than 15°C
RHS · read 11 September 2026
Watering
Water orchids in the morning with lukewarm water: set them in a sink and let water run freely through the foliage and potting medium. Let the pot drain fully so the plants are not left sitting in water.
NC State Extension · read 13 September 2026
Mist the aerial roots regularly, and water once the plant is nearly dry; roots turning pale and silvery show that watering is due.
RHS · read 13 September 2026
Feeding
Feed regularly with balanced fertilizer, either at half strength twice a month or at quarter strength every week. Bud blast (flower buds dropping) can result from shifts in location, fertilizer, moisture, humidity or temperature.
NC State Extension · read 13 September 2026
Through the season, orchid fertiliser can be given at regular intervals.
RHS · read 13 September 2026

How this shows up on a Moth orchid

Crisp margins that appear in winter

On a moth orchid the browning starts furthest from the midrib and works inward, and it crumbles rather than smears. The centre of each leaf is untouched.

Leaf margins are the end of the water supply, so they are the first tissue to run short when the air takes more than the roots can send. Penn State Extension cites 30% to 60% as the recommended indoor range, and a heated room in winter sits below it.

Telling it apart: When it started. Edges that browned as the heating came on point at air; edges that browned through a wet summer do not.

Penn State Extension · read 11 September 2026

Possible causes, likeliest first for a Moth orchid

  1. Most likely cold

    Ranked higher because Moth orchid's recorded problems point this way.

    Its RHS hardiness rating puts this plant's cold floor at 15°C or above, so a cold windowsill at night is a strong explanation.

    • H1A — warmer than 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 moth orchid.
    • Leave damaged leaves until new growth appears, then remove the worst of them.

    What would settle it: Where the moth orchid 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 a build-up of salts in the soil

    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

  3. Most likely too little water

    Ranked lower for Moth orchid because of what its sources say.

    Its source describes well-drained soil for this plant, so soil that dries between waterings is expected. The concern is soil left dry long enough for the plant to go limp or wrinkle.

    • 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

Less likely for a Moth orchid, still possible

Questions

What usually causes brown tips and edges on a Moth orchid?
For Moth orchid: most likely cold, most likely a build-up of salts in the soil and most likely too little water. Its RHS hardiness rating puts this plant's cold floor at 15°C or above, so a cold windowsill at night is a strong explanation.
How can I tell which one it is on my Moth orchid?
Is the browning crisp and dry, or soft and dark? Crisp and dry; Soft and dark.
What do Moth orchid's sources say about its soil moisture?
RHS: Well-drained.
What does this look like on a Moth orchid?
On a moth orchid the browning starts furthest from the midrib and works inward, and it crumbles rather than smears. The centre of each leaf is untouched. Telling it apart: When it started. Edges that browned as the heating came on point at air; edges that browned through a wet summer do not.

Something else wrong with the Moth orchid?

Everything the sources say about Moth orchid

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.