Plant diagnosis

Why does my cyclamen have brown spots?

A cool-room winter bloomer that grows from a tuber — it wilts fast when thirsty, rots fast when the tuber is watered directly, and sleeps through summer on purpose.

SymptomBrown spots

PlantCyclamen

Most likely causeFungal or bacterial leaf spot

Causes to check4 ranked

The 4 most likely causes

The cause of cyclamen brown spotsusually 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.

Fungal or bacterial leaf spot (Possible)
Brown spots with yellow halos appearing on cyclamen, 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.
Sunburn or intense direct sun (Possible)
Bleached patches, papery brown spots, or crisped leaf surfaces on the south-facing side of cyclamen 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.
Overwatering or poor drainage (Likely)
In most homes overwatering is more often a drainage problem than a frequency problem. Cyclamen needs a pot with a drainage hole, a chunky free-draining mix, and a watering rhythm of water from below when the surface dries; keep water off the tuber. Soggy soil drowns the roots and the first symptom you see above ground is yellowing or wilting foliage.
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 cyclamen in particular

Brown, water-soaked patches on cyclamen leaves, especially in the cool, humid conditions the plant enjoys, often signal botrytis grey mould, which this species is notably prone to. It typically takes hold on tired or damaged tissue and on stalks crowded at the crown, sometimes furring over with grey mould and collapsing the leaf or flower stem it infects. Poor airflow and water lingering on the leaves or in the packed centre of the rosette are what let it in.

Normal turnover, or real trouble?

There is no routine, healthy brown spotting on a cyclamen leaf; the nearest harmless mark is a dry, papery patch where a leaf was bruised or caught the sun through glass, and those stay small and dry. Take it seriously when a spot is soft, water-soaked and spreading, especially in the cool, damp, crowded conditions the plant otherwise loves, because that furry, collapsing kind is the grey mould this species is so prone to.

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 cyclamen usually mean low humidity or tap-water minerals.

The fix — step by step

The first move is hygiene and airflow, not a fungicide, since none is available to home gardeners against grey mould. Pick off every affected leaf and flower promptly and bin them, then thin out the crowded centre of the rosette, space the plant away from its neighbours, and improve ventilation so leaves and crown are not left damp. Water only from below and keep drips off the foliage; do not mist a cyclamen.

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

Quarantine if you suspect disease. If spots look wet, are spreading, or have a yellow halo, move cyclamen away from your other plants until you have a diagnosis. Disinfect your tools between plants.
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.
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.
Improve airflow and watering technique. Water at the soil line only — never on the leaves. Space cyclamen so leaves are not touching neighbouring plants. A small fan in stagnant rooms makes a surprising difference.
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 cyclamen 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 cyclamen, the single biggest preventative is matching its native rhythm: water from below when the surface dries; keep water off the tuber, bright indirect light in a cool room (13-18°C is ideal), 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

Why is my cyclamen brown spots?

Cyclamen brown spots is most often caused by fungal or bacterial leaf spot. Remove the worst leaves, switch to filtered water if the species is tap-sensitive, and water at the soil line only.

What is the most common cause of cyclamen brown spots?

The most likely cause is fungal or bacterial leaf spot. Brown spots with yellow halos appearing on cyclamen, 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.