Why does my monstera have brown spots?

The 4 most likely causes

The cause of monstera 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. Low humidity (Likely)
   Monstera is native to humid environments and struggles when household humidity drops below 40%. The first sign is crispy brown leaf tips, followed by pale, curling foliage. A humidifier, a pebble tray, or grouping plants together raises local humidity meaningfully.
2. Fluoride or chlorine in tap water (Likely)
   Monstera is sensitive to the fluoride and chlorine added to most municipal water supplies. Minerals build up at the leaf tips and cause crispy brown edges or speckled spots. Switch to rainwater, filtered water, or tap water that has sat uncovered for 24 hours so the chlorine can off-gas.
3. Fungal or bacterial leaf spot (Possible)
   Brown spots with yellow halos appearing on monstera, 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.
4. Sunburn or intense direct sun (Possible)
   Bleached patches, papery brown spots, or crisped leaf surfaces on the south-facing side of monstera 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.

Why monstera in particular

Brown spots on a Monstera tell their story by texture. Dark, water-soaked patches with a yellow halo, spreading from the leaf edge inward, are the classic sign of overwatering and the bacterial or fungal rot that follows soggy aroid roots. Dry, pale-brown crisp patches in the middle of the blade, by contrast, are usually scorch from direct midday sun this understory plant never evolved to take. Feel whether the spot is wet or crisp before you treat it.

Normal turnover, or real trouble?

Some brown flecks are just scar tissue. A Monstera leaf that unfurled pressed against a wall or was nicked while young often carries a small, dry, hard brown mark that sits there for the leaf's whole life. The honest test is time: ring a spot lightly and look again in a few days. A static, dry fleck is old damage; a margin that has crept outward, softened or gone haloed is active.

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 monstera usually mean low humidity or tap-water minerals.

The fix — step by step

Match the action to the texture. Dry, crisp scorch means simply shifting the plant back from a hot, direct window into bright, indirect light — you can trim the dead edge with a clean blade, but the rest of the leaf keeps working. Wet, haloed spots call for the opposite: remove that whole leaf at the petiole, stop misting, let the mix dry out, and improve airflow rather than reaching first for a fungicide.

This is the recovery sequence Growli walks users through for monstera 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 monstera 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 monstera 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 monstera 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 monstera, the single biggest preventative is matching its native rhythm: when the top 2-3cm of soil is dry, roughly weekly, bright 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
• Monstera care guide — full watering, light, and feeding routine
• Is monstera toxic to cats and dogs? — toxic to pets, per the ASPCA
• How often to water monstera — the watering brief
• When to repot monstera — 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
• Monstera — yellow leaves
• Monstera — curling leaves
• Monstera — drooping
• Snake plant — brown spots