Plant care guide
Monstera Brown Spots: Dry Air, Sunburn, Leaf Spot or Rot?
Updated · First published
Why does my Monstera deliciosa have brown spots?
Brown spots on a Monstera fall into three groups: dry, crisp edges from low humidity, dry mix or salts; bleached-then-brown patches from sun burn; and spreading spots from a leaf disease or rotting roots. Where the spot sits, its texture and whether it grows tell them apart.
What to do first
Look at where the brown starts and feel it. Fix humidity, watering or light for dry edges and sun-facing patches. Cut off leaves with spreading, water-soaked or haloed spots, keep the foliage dry, and check the roots if the plant is also wilting.
Brown spots on a big Monstera leaf are hard to ignore. The good news is that the spot itself gives strong clues. Note where it started, whether it is dry or soft, and whether it has grown since last week.
Diseases are uncommon indoors. Clemson Extension’s houseplant disorders factsheet says most houseplant problems have environmental or cultural causes. Rule those out first.
Match the spot to the cause
| What the browning looks like | Likely cause |
|---|---|
| Dry, crisp brown leaf edges or tips | Low humidity, dry mix, or salt buildup |
| Pale or bleached patch, then brown, on leaves facing a window | Sun burn |
| Spots of similar size with a yellow halo, sometimes sticky or water-soaked | Bacterial leaf spot |
| Yellowing at the leaf edge that turns tan, then dark brown, and moves inward | Anthracnose |
| Tan to black round spots, sometimes ringed, with tiny black dots | Fungal leaf spot |
| Brown leaves plus wilting, wet mix and a dark stem at soil level | Root and stem rot |
Dry edges. UW–Madison Extension’s Monstera article says leaf edges turn brown if humidity is too low. Clemson adds hot, dry air, improper watering and salt accumulation as causes of brown tips and margins. A white or grey crust on the mix or pot rim is a sign of salt buildup.
Sun burn. The UConn Monstera factsheet warns that the large leaves burn easily when moved to brighter light. UW–Madison says plants moved outdoors must be acclimated gradually or the leaves will sunburn. NC State Extension’s Monstera profile recommends moderate brightness but not direct sun.
Bacterial leaf spot. UConn describes dark brown spots with a yellow border, similar in size, often with a sticky ooze. In dry conditions they may turn reddish brown. University of Maryland Extension’s bacterial leaf spot page adds that spots may be angular between veins or start at the leaf margins.
Anthracnose. UConn describes yellowing along the leaf edges that turns tan and then dark brown, spreading inward and killing whole leaves.
Fungal leaf spot. University of Maryland Extension’s fungal leaf spot page describes tan, reddish-brown or black round spots that can merge into large blotches. Clemson notes a possible target pattern and small black dots in dead tissue.
Root and stem rot. UConn lists wilting and flagging leaves, stems girdled at soil level, and brown or black mushy roots.
What to do
For dry brown edges:
- Check the mix before watering. NC State advises watering thoroughly, then letting the top quarter to one-third of the mix dry.
- Raise humidity near the plant. NC State suggests a humidifier or a tray of wet pebbles.
- If you see salt crust, flush the pot with plenty of water and empty the saucer. Clemson also suggests scraping off the crust and adding fresh mix.
For sun burn:
- Move the plant back from direct sun.
- Next time, increase light gradually. The burned patches will stay, but new leaves should be clean.
For spreading spots:
- Cut off badly spotted leaves with clean shears and bin them.
- Keep the leaves dry. UConn advises against misting for anthracnose. Maryland Extension suggests watering early in the day and spacing plants for air flow.
- Keep the plant away from cold. UConn advises avoiding low temperatures and crowding for bacterial leaf spot.
- UConn does not recommend chemicals for bacterial leaf spot. For fungal spots, Clemson lists copper soap and other fungicides for use after removing infected leaves. Follow the label.
For wilting with wet mix: go to our Monstera root rot guide.
When it is something else
Yellowing without distinct spots is covered in our Monstera yellow leaves guide. On variegated plants, browning that starts in the white sections is covered in our Thai Constellation care and problems article.
A brown spot will not heal back to green. Track whether new spots appear after your changes. If they keep spreading on new leaves, send a sample to your local extension diagnostic clinic.
References
- UConn Home & Garden Education Center: Monstera deliciosa
- UW–Madison Extension: Swiss-Cheese Plant, Monstera deliciosa
- Clemson Cooperative Extension, HGIC 2251: Houseplant Diseases & Disorders
- University of Maryland Extension: Fungal Leaf Spots on Indoor Plants
- University of Maryland Extension: Bacterial Leaf Spots on Indoor Plants
- NC State Extension Gardener Plant Toolbox: Monstera deliciosa
How this guide was put together: UConn Home & Garden Education Center, UW–Madison Extension, Clemson Extension, University of Maryland Extension and NC State Extension guidance.