Why is Your Monstera Turning Black & How to Fix it

It started slowly enough that I almost missed it. A brand new leaf had unfurled and was quietly darkening at the edge, day by day, and I assumed it was just maturing until the colour tipped from deep green into something closer to black.

That’s what sent me down the research rabbit hole behind this guide.

A monstera turning black is one of the more alarming things a plant can do, because unlike yellowing or drooping, black tissue is dead and will not turn green again. But it’s rarely a reason to panic.

The cause is almost always one of a handful of things: overwatering and root rot, underwatering, too much or too little light, a fungal or bacterial infection, temperature stress, nutrient deficiency, or pests. T

his guide walks through how to tell them apart and what to do about each one.

Why Black Leaves Are a Warning Sign, Not Just a Cosmetic Issue

It’s tempting to snip off a black leaf and move on, but that only treats the symptom.

Leaves are where a monstera makes its food through photosynthesis, and black tissue has no chlorophyll left, so it contributes nothing and can attract disease-causing organisms that feed on the dead cells.

Left unaddressed, the same underlying problem will usually claim another leaf, and then another.

Diagnose the Cause by What the Black Looks Like

Where the black appears, how it feels, and how it spreads all narrow down the cause faster than a generic checklist.

Use the table below to find the closest match, then jump to the matching section.

1. Overwatering and Root Rot

This is the single most common cause of black leaves on a monstera. Waterlogged soil pushes air out of the compost, roots can’t get oxygen, and root rot sets in.

By the time black patches show up on the leaves, the roots have usually already suffered real damage.

Signs of an overwatered monstera

• Drooping or limp leaves despite moist or wet soil
• Yellowing that develops alongside or before the black patches
• Black or dark brown patches that feel soft, not crispy, often at the leaf edge or centre
• A sour or swampy smell from the soil, and mushy roots or stem base if you unpot it

What causes it

• Watering on a fixed schedule instead of checking the soil first
• Low light, which slows photosynthesis and water uptake, leaving the soil wet for longer
• A potting mix that holds too much water, or a pot with poor or no drainage holes

How to fix it

Let the top 5cm (2in) of soil dry out before watering again, and if you’re unsure whether it’s dry, wait rather than guess.

See our full monstera watering schedule for how to build a routine around your plant’s actual drying time rather than a fixed calendar.

Water sparingly through autumn and winter, since the plant uses far less while dormant.

If you suspect root rot, unpot the plant, trim away any soft, brown or black roots back to firm white tissue with clean, sharp scissors, then repot into a fresh, well-draining aroid soil mix in a pot with proper drainage.

Our guide to choosing the best pot for a monstera and to root-bound monstera care cover what to look for when you repot.

One more thing worth knowing before you repot: a leaf that blackens in the week or two after a repot is often transplant shock rather than a sign the repot went wrong.

Disturbing the roots, even carefully, is stressful for the plant, and losing a single leaf during recovery is common and not a reason to intervene further.

Give the plant a few weeks in stable conditions before troubleshooting anything else.

2. Edema (Oedema)

Edema is a physiological reaction rather than a disease, and it catches a lot of monstera owners out because it looks alarming but is not caused by pests or infection.

It happens when the roots take up water faster than the leaves can transpire it away, so pressure builds inside the leaf cells until they rupture.

• Small, raised, water-soaked bumps or blisters, most often on the underside of older leaves
• Blisters that harden into corky, dark brown or black patches over time
• Symptoms appearing shortly after a heavy watering, a spell of low light, or a stretch of still, humid air

Unlike overwatering, edema is not really about how much water is in the soil so much as how quickly the plant can move it back out through its leaves. C

ool temperatures, still air, and low light all slow transpiration and make edema more likely even when your watering routine has not changed.

Improve air movement around the plant with a small fan or by simply giving the room some ventilation, water in the morning rather than the evening so the plant has daylight hours to use it, and avoid watering heavily right before a stretch of dull, humid weather if you can help it.

According to the RHS, oedema is not usually a serious problem, and it does not call for a repot or a fungicide.

Trim off badly affected leaves if the marks bother you, but otherwise the plant should grow out of it once conditions improve.

3. Underwatering

Underwatering has less severe consequences than overwatering, since the damage is usually limited to leaves and stems rather than the root system, but prolonged neglect will still cause lasting damage.

• Wilting or crispy, papery leaves
• Leaf drop
• Browning that starts at the tips and edges and can progress to black, crispy patches

Water thoroughly with room-temperature water until it runs from the drainage holes, then let it drain fully.

If the soil has dried out so much it repels water, stand the pot in a few centimetres of water for 20 to 30 minutes so the compost rehydrates evenly.

Going forward, a consistent watering schedule based on how quickly your specific pot and mix dry out will prevent both extremes.

4. Not Enough Light

Without enough light, a monstera can’t photosynthesise properly, which shows up as darkening or loss of colour in the leaves, and variegated varieties can lose their variegation entirely.

It also means the plant uses less of the water you give it, which quietly increases the risk of overwatering on top.

• Darkening or dulling of leaf colour, sometimes progressing toward black
• Stunted or leggy growth as the plant stretches toward the nearest light source
• Small new leaves that contribute little photosynthesis
• Soil that stays damp for longer than usual even on a normal watering routine

Move the plant somewhere brighter, ideally a few feet from an east-facing window, or a similar distance back from a south or west-facing one. Full detail on how much and what type of light your monstera needs is in our monstera light requirements guide.

If natural light is limited, a full-spectrum grow light is a reliable alternative, just introduce it gradually.

If you have a variegated monstera, it is also worth knowing that the white or cream sections of the leaf carry little to no chlorophyll, so they have almost none of the plant’s natural defences and often brown or blacken well before the green sections show any stress.

A bit of browning confined to the white patches on an otherwise healthy variegated leaf is usually just the nature of variegation rather than a sign you are doing something wrong.

5. Too Much Direct Light (Sunburn)

Monsteras are understory plants in the wild, filtering light through a forest canopy rather than sitting in direct sun.

Too much direct, intense light scorches the leaf tissue, and unlike most other causes on this page, sun damage is permanent and won’t recover once it’s happened.

• Black or brown crispy patches, often on the side of the leaf facing the light
• A limp or slightly dehydrated appearance as the damaged tissue loses moisture faster

Move the plant out of direct sun, or add a sheer curtain to filter the light. Our guide to whether monstera can tolerate direct sunlight explains which situations are safe and which aren’t.

When relocating a plant to a brighter spot for any reason, do it gradually over a week or two so it can adjust, rather than moving it straight into strong sun.

6. Fungal, Bacterial, or Anthracnose Leaf Spot

This is the cause most guides skim over, but it’s worth checking properly if the black spots don’t fit neatly into an overwatering or light pattern.

Fungal and bacterial leaf spot diseases both thrive in damp, humid conditions with poor airflow, and telling them apart changes how you treat it.

In both cases, remove infected leaves with sterilised scissors, avoid overhead watering and misting directly onto foliage, space plants out to improve airflow, and isolate the plant from healthy ones nearby while it recovers.

According to Clemson University’s Home & Garden Information Center, bacterial leaf spots on houseplants typically stay localised to the foliage if caught early, and the plant can usually be saved, but the outlook is worse if the infection spreads into the stems.

A less common but related possibility is anthracnose, a fungal disease that shows up as small, dark, sunken lesions rather than the flatter spots typical of standard leaf spot, often starting at the leaf margin or tip and spreading inward in concentric rings.

It thrives in the same warm, humid, poorly ventilated conditions as fungal leaf spot, and the treatment is the same: remove affected leaves, improve airflow, and avoid wetting the foliage.

7. Temperature Stress

Monsteras are tropical plants. The RHS growing guide for Swiss cheese plants recommends keeping them at 18 to 25°C (64 to 77°F) with moderate humidity.

Outside that range, cold causes cell damage that shows up as blackened patches, particularly on leaves closest to a cold window or draught, while excessive heat increases water loss and can cause a similar effect through dehydration.

See our full guide to caring for a monstera in winter for season-by-season adjustments to watering, light, and positioning.

8. Nutrient Problems: Underfeeding and Overfeeding

Underfeeding

Less common than the causes above, but worth ruling out if you haven’t repotted or fed the plant in a long time.

A lack of potassium or magnesium in particular can cause dark or blackened patches, often alongside stunted growth and weaker stems, and the symptoms can look similar to low light stress.

During the growing season, feed with a balanced monstera fertiliser diluted to half strength, applied when watering rather than to dry soil.

Don’t feed in autumn or winter, and never feed a plant that’s already stressed from overwatering or root damage, since fertiliser salts can burn what root system is left.

Overfeeding and Salt Burn

Too much fertiliser causes at least as much damage as too little.

Fertiliser salts build up in the soil faster than the plant can use them, drawing moisture out of the roots rather than into them, which shows up as crispy black or brown patches and tips, often with a crust of white mineral deposit visible on the soil surface or around the drainage holes.

• Crispy, blackened leaf tips and margins, sometimes alongside stunted growth
• A white, crusty build-up on the soil surface or the rim of the pot
• Symptoms that worsen after a recent feed rather than after watering

Tap water contributes to the same problem even if you never overfeed.

Most UK mains water carries chlorine and fluoride, and fluoride in particular accumulates in the soil over time and can scorch sensitive leaf tips and margins, as flagged by Michigan State University Extension research into fluoride toxicity in houseplants.

If you can, let tap water stand uncovered for 24 hours before using it so the chlorine can dissipate, or switch to filtered or rainwater if the problem persists.

Flush the soil thoroughly with several times its volume of plain water and let it drain fully to wash out built-up salts, hold off on feeding for a few weeks, and resume at half strength once new growth looks normal again.

9. Pests

Weakened plants are more vulnerable to pests, and an infestation can itself cause dark spotting as insects feed on sap and damage cells.

Check leaf undersides and the joints where stalks meet the stem for webbing, sticky residue, or small moving insects.

Our guide to the most common monstera pests covers identification and treatment for the main culprits, including spider mites, mealybugs, and scale.

Why Did a New Leaf Turn Black While Unfurling?

This is what happened to the leaf I mentioned at the start, and it catches a lot of people out because the plant otherwise looks healthy.

A new leaf develops fully formed inside a protective sheath before it unfurls, so if it emerges already damaged or darkens shortly after opening, the stress that caused it usually happened weeks earlier, while the leaf was still forming, not on the day you noticed it.

The most common triggers are waterlogged soil around the time the leaf was developing, a cold shock, transplant stress after a repot, or general environmental stress such as a house move or a change of position.

The damaged leaf itself won’t recover, but that doesn’t mean the plant is in trouble. As long as the roots are healthy and current conditions are stable, the next leaf the plant produces should unfurl normally.

Should You Cut Off Black Monstera Leaves?

It depends on the cause. If the black tissue is confined and came from physical damage, cold, or sunburn, the rest of the leaf is often still green and functional, so you can leave it in place and let it keep photosynthesising through its healthy sections.

If the black patches are from disease or pests, remove the affected leaves promptly with sterilised scissors to stop them spreading to the rest of the plant.

Cut close to the stem, and dispose of the removed material away from your other plants rather than composting it nearby.

If a large portion of the plant is affected, remove leaves in stages over a week or two rather than all at once, which gives the plant a chance to keep producing food from its remaining healthy foliage while it recovers.

If only a leaf or two is affected and the rest of the plant looks strong, you can safely remove them in one go.

A quick safety note while you’re trimming: monstera sap can irritate skin, and the plant is toxic to pets and humans if ingested.

Wear gloves when handling cut roots, stems, or diseased leaves, and keep the trimmings away from pets and children.

Frequently Asked Questions

Will a black monstera leaf turn green again?

No. Black tissue is dead and won’t recover its colour or function.

The plant can still produce healthy new leaves once the underlying cause is fixed, so focus on prevention rather than trying to revive the damaged leaf itself.

Is it normal for one leaf to turn black while the rest of the plant looks fine?

Yes, this is common with physical damage, a single cold night, or a leaf that was already forming when a stress event happened.

It’s only a wider concern if new leaves keep emerging damaged or several leaves are affected at once.

Can a monstera survive after its leaves turn black?

Yes, in most cases, provided the roots are healthy or can be brought back with prompt treatment.

See our full monstera care guide if the plant is showing wider signs of decline beyond the leaves.

Why are my monstera’s leaves turning yellow and black?

This combination usually points to overwatering, since yellowing often precedes the black patches as root damage worsens.

See our guide to monstera leaves turning yellow for how to confirm this and adjust your watering.

Why is my monstera drooping and turning black at the same time?

Drooping alongside black patches almost always means the roots are compromised, most often from overwatering.

Our monstera drooping guide covers how to check and confirm this.

How do I stop black spots spreading to other leaves?

Remove affected leaves promptly, sterilise your scissors between cuts, avoid wetting the foliage when watering, and improve airflow around the plant.

If disease is suspected, keep the plant apart from other houseplants until it has fully recovered.

What does edema look like on a monstera, and is it serious?

Edema shows up as small, raised, water-soaked bumps that harden into corky brown or black patches, usually on the underside of older leaves.

It looks alarming but is a physiological reaction to the roots taking up water faster than the leaves can release it, not a disease.

Improving airflow and easing off on heavy watering during dull, humid spells usually resolves it.

Why do the white patches on my variegated monstera turn brown or black?

The white or cream sections of a variegated leaf contain little to no chlorophyll, so they have far fewer natural defences than the green sections and often brown first.

If the browning stays confined to the white areas and the green sections still look healthy, this is normal for variegated monsteras rather than a sign of a care problem.

Is a black stem more serious than a black leaf?

Yes. Blackening confined to leaf tissue is rarely urgent, but if the discolouration spreads into the petiole or main stem and the tissue feels soft or mushy, treat it as an emergency.

Cut back to firm, healthy tissue straight away, since stem infections spread much faster than leaf infections and can kill the plant.

Key Takeaways

• Black tissue is permanent, but the plant can still recover and grow new, healthy leaves.
• Overwatering and root rot are the most common cause, so check the soil and roots before repotting or treating anything else.
• Fungal and bacterial leaf spot look similar but need different responses, and fungicide won’t help a bacterial infection.
• A new leaf that unfurls already damaged was usually stressed weeks earlier, while it was still forming.
• Remove diseased or pest-damaged leaves promptly, but leave leaves that are only cosmetically marked if most of the tissue is still green and functional.
• Edema, natural leaf ageing, and variegation browning can all look worrying but usually need no treatment beyond a small adjustment to conditions.
• Blackening that spreads from a leaf into the petiole or main stem is more urgent than an isolated leaf spot and should be cut back immediately.

Next Steps

For everything else your monstera needs to stay healthy long term, from watering and light through to repotting and feeding, see our full monstera care guide.