Plant care guide
Peperomia Brown Spots: Leaf Spot, Edema, Sun or Rot?
Updated
Why does my Peperomia have brown spots?
Brown spots on peperomia leaves usually come from a fungal or bacterial leaf spot, corky edema swellings on the leaf undersides, or sun scorch. Spots with rings that spread across many leaves can mean a virus, and a black, mushy base means stem rot.
What to do first
Look at where the spots sit and what they feel like. Remove spotted leaves, water the mix rather than the foliage, and let it dry between waterings. Move the plant out of direct sun, and discard it if soft black rot spreads up from the soil line.
Brown spots on a peperomia can look alike at first glance, but the causes need very different fixes. Some are a fungus you can stop spreading. Some are water stress showing on the leaf. A few mean the plant is better replaced.
Turn the leaf over and look closely before you treat anything.
Sort the spots
| What you see | Likely cause |
|---|---|
| Small brown spots with yellowish margins, sometimes in rings or with tiny black dots | Fungal leaf spot |
| Water-soaked spots, often with a yellow halo, drying reddish-brown | Bacterial leaf spot |
| Raised, corky, tan to brown bumps on the leaf underside | Edema, or Cercospora leaf spot |
| Dry, dark rings spreading from the leaf edge (watermelon peperomia) | Phyllosticta leaf spot |
| Mushy, dark-brown to black spots with rings | Rhizoctonia leaf spot |
| Dry, bleached or brown patches on the sunny side | Sun scorch |
| Rings or brown dead patches, distorted leaves, stunting | Ringspot virus |
| Black, mushy stem at the soil line spreading into leaves | Stem and root rot |
Leaf spots. Clemson Extension’s houseplant diseases factsheet describes fungal spots as small and brown with yellowish margins. They may show a target pattern or tiny black fruiting bodies. It describes bacterial spots as water-soaked, usually uniform in size, sometimes with a yellow halo. Clemson’s peperomia guide says fungal leaf spots can be prevented by keeping the leaves dry when watering.
Edema or Cercospora. A UF/IFAS peperomia production guide (Henley, Osborne and Chase) describes Cercospora leaf spot. It forms tan to black, raised, swollen areas on leaf undersides that look like edema. It says the two are often confused. Baby rubber plant (Peperomia obtusifolia) cultivars are especially susceptible. Clemson says edema forms rough, corky swellings on lower leaf surfaces. It names wet soil, poor light and low temperatures as triggers, most often on succulent plants in winter.
Other spots. The same UF/IFAS guide describes Phyllosticta leaf spot on watermelon peperomia and Rhizoctonia leaf spot on P. obtusifolia. It also covers peperomia ringspot virus, which can cause ring patterns and leaf distortion on green forms and brown dead areas on variegated ones.
Sun. NC State Extension’s baby rubber plant profile says sunlight that is too strong or direct will burn the leaves. Clemson agrees that direct sun may scorch them.
What to do
- Isolate the plant from other peperomias while you work out the cause.
- Remove spotted leaves and fallen debris. Clemson notes leaf spot fungi survive on dead plant matter in the soil. UF/IFAS advises removing and destroying Phyllosticta-infected leaves.
- Keep the leaves dry. Water the mix, not the foliage, as Clemson advises.
- Let the mix dry between waterings. Clemson says peperomia prefers this. UF/IFAS says its roots are very sensitive to waterlogged soil, which also favours root rot fungi.
- Fix the light. Clemson suggests indirect light from an east- or south-facing window, out of direct sun.
- For edema, change the conditions. Clemson says affected leaves won’t recover, but more light, less frequent watering and better drainage halt the decline. Never leave the pot standing in a saucer of water.
If you suspect a virus, UF/IFAS says no chemical controls it. Discard affected plants, and don’t take cuttings from them.
If the stem is black and mushy at the soil line, UF/IFAS describes Phytophthora and Pythium rot as very serious on P. obtusifolia. Throw the plant away with its mix, and use a new or scrubbed pot next time. If a stem tip is still firm and clean, you can try rooting it; NC State notes peperomias grow from leaf and stem cuttings.
Prevent it
- Use fresh, pathogen-free potting mix and clean pots, as UF/IFAS advises.
- Give plants good air circulation and avoid splashing the leaves, as Clemson advises; splashing spreads leaf spot fungi.
- Water less in winter, when edema is most likely.
- Keep the plant out of cold draughts, as NC State’s Peperomia genus profile recommends.
UF/IFAS’s baby rubber plant fact sheet also lists mites as the main pest. Check the undersides for speckling while you look for spots.
Yellowing rather than spotting is covered in our peperomia yellow leaves guide. A limp, wet plant belongs in our peperomia drooping guide. For blister-like bumps on other plants, see edema in houseplants. Leaf spot across species is covered in leaf spot diseases of houseplants. The peperomia hub lists our other guides.
References
- UF/IFAS CFREC-Apopka: Peperomia Production Guide, Foliage Plant Research Note RH-91-25 (archived)
- Clemson Cooperative Extension, HGIC 2251: Houseplant Diseases & Disorders
- Clemson Cooperative Extension HGIC: Peperomia Indoor Plant Care and Growing Guide
- NC State Extension Gardener Plant Toolbox: Peperomia
- NC State Extension Gardener Plant Toolbox: Peperomia obtusifolia
- UF/IFAS Extension: Peperomia obtusifolia, Baby Rubber Plant (FP466)
How this guide was put together: UF/IFAS, Clemson Extension and NC State Extension guidance.