Why Does My Pothos Have Black Spots?

Search this and every result will tell you the same thing: fungal or bacterial leaf spot.

I’ve been doing this a long time and that is almost never my first thought. When I see black spots on a Pothos, I assume roots or pests until something tells me otherwise, and most of the time I’m right.

The internet starts at the wrong end. Fungal and bacterial infections are real, and there’s a full section on them further down, but they’re the least likely explanation on a normal houseplant in a normal house, and reaching for a fungicide before you’ve looked at the roots is how people spend three weeks treating the wrong thing.

So we’ll work through it in the order that actually finds the answer.

One quick note on terminology. This article is about discrete dark spots. If what you have is solid brown areas, crispy tips or browning edges, that’s a different symptom with different causes.

Why Are My Pothos Leaves Turning Brown?

The questions, in order

1. Does it wipe off?

Take a damp cloth to it.

If a black film or sooty patches come away and leave clean green leaf underneath, that’s sooty mould, and it isn’t a leaf infection at all. It’s a fungus growing on honeydew, the sugary waste that sap-sucking pests excrete onto the leaves below them.

The mould is harmless in itself. The pests producing the sugar are your actual problem, and they’ll be sitting somewhere above the affected leaves. Look for mealybugs in the leaf joints and scale on the stems.

Mealybugs On Pothos: The Complete Guide

Nothing else in this article wipes off, so this takes ten seconds and rules out a whole category.

2. Front of the leaf, back, or both?

Spots appearing on the back of an older leaf, followed by gradual yellowing: this is likely a leaf being retired, and it’s completely normal. More on that below, because it’s the most reassuring answer here and the one people most often mistake for disease.

Spots on the upper surface only: more likely damage, pests or infection.

Spots visible on both sides, in the same places: the damage goes through the full thickness of the leaf, which points towards infection or serious cell death rather than surface damage.

3. Are they spreading?

Photograph the leaf and look again in four days.

Static. Something happened once. Physical damage, a knock, a pet, an old event that has already finished. Nothing to treat.

Spreading across the leaf, or appearing on new leaves. Something is ongoing, and now it’s worth working out what.

This one question saves an enormous amount of unnecessary panic, and almost nobody does it.

4. What shape are they?

Ragged, torn, with damaged edges. Teeth. Cat teeth, usually.

Little nippy cat bites are one of the most common causes of black spots on a Pothos and one of the least suspected. The bite itself is invisible within a day or two, and what you notice a week later is a dark mark where the damaged tissue died back. If the marks are at cat height, or on the trailing vines, or on the leaves nearest the edge of a shelf, you can stop investigating.

Why Are My Pothos Leaves Turning Brown?

Tiny black specks, more like grains than spots, often alongside silvery patches. That’s thrips, and the specks are their waste rather than damage.

Thrips on Pothos: How To Identify and Get Rid Of Them

Dark, wet-looking spots with a yellow ring around them. Now we might be talking about bacterial infection. See the section below.

Round spots with defined edges, sometimes with a dry papery centre or faint rings. Possibly fungal. Also below.

5. What are the roots doing?

If the spots are spreading and nothing above has explained them, get the plant out of its pot.

Firm roots are fine. Some Pothos have naturally dark roots, so go by texture rather than colour. Mushy, soft, unpleasant roots mean the plant is failing from the bottom and the leaves are reporting it.

This is my first suspicion for spreading black spots and it’s the last thing most people check.

Root Rot In Pothos: Can You Save It?

6. What sort of room is it in?

Specifically: is it humid, and is it dark or cold?

That combination is the one that lets leaf infections take hold. Warm, bright, moving air is inhospitable to them. Damp, dim and chilly is an invitation.

The reassuring answer: the plant is retiring a leaf

If it’s an older leaf, and the spots appeared on the underside, and the leaf is slowly yellowing, your plant is fine.

Plants don’t simply drop leaves they’re done with. Before shedding, they pull the useful material back out: nitrogen, phosphorus, magnesium, anything worth keeping. That process leaves the leaf visibly deteriorating, and dark patches on the underside are often the first sign.

It’s the plant recycling, not the plant suffering. A Pothos in good conditions still sheds its oldest leaves periodically, and the giveaway is that it’s happening to the oldest leaf on the vine while everything above it looks healthy and new growth keeps coming.

Why Are My Pothos Leaves Turning Yellow?

If it really is fungal or bacterial

Sometimes it is. Here’s how to tell which, and what to actually do.

Bacterial leaf spot tends to look wet. The spots have a dark, water-soaked, slightly greasy quality, often with a yellow halo around them, and the edges are irregular. It can spread along the veins, and it moves fast in damp conditions. In bad cases the affected tissue goes soft and smells unpleasant.

Fungal leaf spot tends to look dry. Spots are more likely to be round with defined margins, sometimes with a papery brown centre, occasionally with faint concentric rings. If you look very closely you may see minute dark dots in the centre, which are the fungus’s fruiting structures. It generally spreads more slowly than bacterial infection.

The caveat: you cannot reliably tell them apart at home, and plenty of plant pathologists wouldn’t commit without a lab. Fortunately it matters less than you’d think, because most of the response is identical either way.

What to do:

• Remove the affected leaves entirely, at the stem. Don’t compost them, bin them.
• Stop getting the foliage wet. Water the soil, not the plant.
• Isolate it from your other plants until it stops spreading.
• Improve airflow, light and warmth. This is the part that matters.
• Sterilise your scissors between cuts.

You can try an antifungal if you want to, and there are plenty available. Two things to know: they do nothing at all against bacterial infection, and they won’t hold if the conditions that caused the problem are still in place. A fungicide on a plant sitting in a cold, dim, damp corner is a delaying tactic.

The conditions are the cause. Fix those and the problem usually stops without anything else.

Which brings us to misting

If your Pothos has an actual fungal or bacterial leaf infection, and you’ve been misting it, stop.

Leaf infections need moisture sitting on the leaf surface to establish and spread. Misting provides exactly that, repeatedly, in a spot that’s often chosen for being cosy rather than bright and airy. It’s the one care habit that reliably makes this specific problem worse.

It doesn’t deliver the humidity benefit people think it does either, but that argument lives elsewhere.

Pothos Humidity: What You Need To Know (And Why Misting Does Nothing)

Should you remove the spotted leaves?

Static spots from damage or a pet: leave them. The leaf is still working and still feeding the plant. There’s no benefit to removing a functional leaf because it has a mark on it, beyond how it looks to you.

Leaves being naturally retired: leave them alone until they’ve mostly yellowed. The plant is still extracting value from them, and pulling them early throws that away. Take them off when they come away easily.

Suspected infection: remove them properly, at the stem, and bin them.

Anything more than about half damaged: worth removing regardless. It’s costing the plant more than it’s returning.

Frequently asked questions