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Arrowhead plant spots on leaves: causes and what to do

8 results in the diagnosis tree begin with spots on the leaves, 5 of them marked likely when the answers fit. They are ordered here for Arrowhead plant (Syngonium podophyllum), using what its sources say about light, soil moisture, humidity and pests and diseases and one problem recorded for it.

Sources last read 14 September 2026.

Start the diagnosis for this Arrowhead plant

Arrowhead plant (Syngonium podophyllum), the whole plant.
Dandarmkd, CC BY-SA 4.0 · Wikimedia Commons

Syngonium podophyllum is a species of aroid that is a popular houseplant. Common names include: arrowhead plant, arrowhead vine, arrowhead philodendron, goosefoot, nephthytis, African evergreen, and American evergreen. Wikipedia, CC BY-SA 4.0

Native range: Mexico to Trop. America (wet tropical). Also sold as African evergreen, American Evergreen, Arrow-Head Vine, Arrowhead Vine, nephthytis and Trileaf Wonder.

What Arrowhead plant’s sources say that bears on this

Light
Medium light
Clemson Extension · read 13 September 2026
Partial shade
RHS · read 13 September 2026
Soil moisture
Moist but well-drained
RHS · read 13 September 2026
Humidity
ASHRAE recommends indoor relative humidity between 30% and 60%
Penn State Extension · read 13 September 2026
Pests and diseases
Can be troubled by aphids, twospotted spider mites, mealybugs and banded greenhouse thrips. Diseases: bacterial leaf spot.
NC State Extension · read 13 September 2026
In a greenhouse, greenhouse red spider mite and mealybugs can occur. Diseases: usually none.
RHS · read 13 September 2026

How this shows up on an Arrowhead plant

Brown or black spots on the leaf blades that grow and merge

Brown to black spots appear on the leaf blades of the arrowhead plant, often ringed with yellow, and enlarge until patches of the leaf blade die.

NC State Extension lists leaf spot among the diseases it may get. The pathogen enters through the leaf surface while it is wet and kills the tissue around it.

Telling it apart: Where the spots are. Disease scatters spots anywhere, often where water sits; cold damage and scorch mark one side.

NC State Extension · read 13 September 2026

Possible causes, likeliest first for an Arrowhead plant

  1. Most likely a leaf-spot infection

    Ranked higher because Arrowhead plant's recorded problems point this way.

    • Brown or black spots on the leaf blades that grow and merge NC State Extension

    Why: Spots with a yellow ring around them are the mark of a fungus or bacterium spreading through the leaf, the ring being tissue that is dying ahead of it.

    What to try:

    • Remove the affected leaves and put them in the bin rather than the potting mix.
    • Water the soil rather than the leaves, and stop misting.

    What would settle it: Whether the spots grow. Mark the edge of one with a pencil dot and look again in a week; an infection advances, damage from a single event does not.

    Check this with the questions

  2. Most likely cold

    Ranked higher for Arrowhead plant because of what its sources say.

    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 13 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 arrowhead plant.
    • Leave damaged leaves until new growth appears, then remove the worst of them.

    What would settle it: Where the arrowhead plant 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

  3. Most likely spider mites

    Why: Spider mites feed on individual leaf cells, and each emptied cell shows as a pale speck.

    What to try:

    • Move the arrowhead plant away from other plants.
    • Wash the leaves, top and underside, with a strong spray of water in a shower or sink.

    What would settle it: Hold a sheet of white paper under a leaf and tap the leaf. Tiny specks that move across the paper are mites.

    Check this with the questions

Less likely for an Arrowhead plant, still possible

Questions

What usually causes spots on the leaves on an Arrowhead plant?
For Arrowhead plant: a leaf-spot infection, cold and spider mites.
How can I tell which one it is on my Arrowhead plant?
What do the marks look like? Pale, dry, bleached patches on the side facing the window; Brown or black spots, many with a yellow ring around them; Tiny pale speckles all over, sometimes with fine webbing underneath; A white powdery coating that wipes off; Silvery streaks with tiny black dots; Dark, soft, water-soaked patches.
What do Arrowhead plant's sources say about its light?
Clemson Extension: Medium light. RHS: Partial shade.
What does this look like on an Arrowhead plant?
Brown to black spots appear on the leaf blades of the arrowhead plant, often ringed with yellow, and enlarge until patches of the leaf blade die. Telling it apart: Where the spots are. Disease scatters spots anywhere, often where water sits; cold damage and scorch mark one side.
Is Arrowhead plant 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 Arrowhead plant?

Everything the sources say about Arrowhead plant

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.