Why does my chinese evergreen have brown spots?

The 4 most likely causes

The cause of Chinese evergreen brown spots usually narrows to one of the items below, ranked by how often we see each in Growli's diagnostic chats. Work down the list — most readers find their answer in the top two.

1. Fungal or bacterial leaf spot (Possible)
   Brown spots with yellow halos appearing on Chinese evergreen, especially after water sat on the leaves overnight, are most often fungal or bacterial leaf spot. Remove affected leaves, water only at the soil line, improve airflow, and apply a copper fungicide if it spreads.
2. Sunburn or intense direct sun (Possible)
   Bleached patches, papery brown spots, or crisped leaf surfaces on the south-facing side of Chinese evergreen are sunburn. Acclimatise it more gradually after a move, or filter midday sun with a sheer curtain. Sunburn damage doesn't heal — wait for new growth.
3. Overwatering or poor drainage (Likely)
   In most homes overwatering is more often a drainage problem than a frequency problem. Chinese evergreen needs a pot with a drainage hole, a chunky free-draining mix, and a watering rhythm of when the top 3cm of soil is dry, every 7-10 days. Soggy soil drowns the roots and the first symptom you see above ground is yellowing or wilting foliage.
4. Pests sucking sap (Possible)
   Sap-sucking pests (aphids, spider mites, mealybugs, scale) all cause similar symptoms: yellow stippling, distorted new growth, sticky residue. Inspect leaf undersides and stem joints with strong light. Most are controlled with weekly insecticidal soap or a horticultural oil spray.

Why Chinese evergreen in particular

The classic Aglaonema brown mark is chilling injury: greasy, grey-to-dark patches between the midrib and margin of the older leaves, appearing two to ten days after the plant sat below about 15C or in cold draught. Soft, water-soaked spots that spread in humid, poorly ventilated conditions point instead to bacterial or fungal leaf spot. Bleached, dry patches mean this understory plant was moved into direct sun its thin leaves never evolved to take.

Normal turnover, or real trouble?

No brown mark is truly normal here, but not all are urgent. An old, dry, sharply-defined patch that has not changed in weeks - a healed knock, or a static cold blemish - is cosmetic history you can ignore. What demands action is a spot still enlarging, ringed by a yellow halo, or soft and water-soaked at its edge. Reassuringly, if each new leaf unfurls clean, the trouble is not running through the whole plant.

How to diagnose in 60 seconds

Run these quick checks before you change anything — the right fix depends on what you find.

• Are the spots dry and crisp or wet and spreading? Crisp = sunburn, fluoride, or old damage; wet = active fungal or bacterial spot.
• Do the spots have a yellow halo? Halos are classic for bacterial and fungal leaf spot.
• Are they only on the sunny side of the plant? That points to sunburn.
• Are the leaf tips uniformly brown while the rest is healthy? Crispy tips on Chinese evergreen usually mean low humidity or tap-water minerals.

The fix — step by step

Stop wetting the foliage at once - keep water in the soil, not on the leaves, and let the surface dry between the fingers. Aglaonema loves still, humid air, but that same stillness lets a spreading leaf spot travel, so open up airflow and space it from neighbours even while you keep humidity up around it. Snip off any water-soaked, enlarging spotted leaves with clean scissors and bin them rather than composting.

This is the recovery sequence Growli walks users through for Chinese evergreen with brown spots. Work through the steps in order; skipping ahead is the most common reason a plant fails to bounce back.

1. Quarantine if you suspect disease. If spots look wet, are spreading, or have a yellow halo, move Chinese evergreen away from your other plants until you have a diagnosis. Disinfect your tools between plants.
2. Remove the worst-affected leaves. Snip off heavily spotted leaves at the base. Don't compost them — bag and bin to stop spore spread. Never remove more than 30% of foliage in one go.
3. Switch to filtered or rain water. If you suspect tap-water damage, water with rainwater, distilled water, or tap water that has stood uncovered for 24 hours. Continue for 4-6 weeks before re-evaluating.
4. Improve airflow and watering technique. Water at the soil line only — never on the leaves. Space Chinese evergreen so leaves are not touching neighbouring plants. A small fan in stagnant rooms makes a surprising difference.
5. Apply a treatment if needed. For active fungal spread, a copper-based fungicide applied weekly per the label is the standard remedy. For sunburn or fluoride damage, no treatment helps — just remove damaged leaves and wait for new growth.

When this can't be saved

Most cases of Chinese evergreen brown spots are recoverable, but a few red flags point to a plant that has gone past the point of return. If you spot any of these, consider propagating a clean cutting and starting over.

• Spots are spreading by several per day across multiple leaves — active aggressive disease.
• The whole crown of the plant is blackening from a central point outward.
• Healthy-looking neighbouring plants are starting to show the same symptoms.

Prevention

For Chinese evergreen, the single biggest preventative is matching its native rhythm: when the top 3cm of soil is dry, every 7-10 days, low to medium indirect light, and a free-draining pot with a working drainage hole. Water at the soil line, not the leaves, especially in the evening when leaves can't dry before nightfall. Switch to filtered or collected rainwater for sensitive species — it pays for itself in fewer crispy edges. Improve airflow around densely planted shelves with a small clip-on fan.

Common questions

Related guides

• What's wrong with my plant? — the diagnosis apps compared
• Is Chinese evergreen toxic to cats and dogs? — toxic to pets, per the ASPCA
• How often to water Chinese evergreen — the watering brief
• When to repot Chinese evergreen — pot size and timing
• Brown spots on plants — the full diagnostic guide across species
• What's wrong with my plant? — Growli's flagship diagnosis index
• Chinese evergreen — yellow leaves
• Chinese evergreen — curling leaves
• Chinese evergreen — drooping
• Monstera — brown spots