Calathea plants have bright, colorful leaves and make a great addition to any home. Native to the tropics, Calathea are fond of humidity and warm conditions. They thrive in low to medium light and moist soil. Brown spots on Calathea can be due to several reasons, including low humidity, excess sun, or insufficient water. Find out more about what to do when brown spots pop up and how to fix this issue.
Check out this Calathea Care Guide for more information about general Calathea care.
1. Brown spots on Calathea due to dry soil
Calathea thrive in moist soil. It is important to keep a balance between under and over watering because dry soil leads to brown spots and curled leaves, while soaking wet soil leads to root rot.
Check that the top 1 to 2 inches of soil are dry before watering. Water enough to moisten the soil without soaking it.
Dump out the excess water that collects in the saucer so the plant does not sit in it for too long.
A plant that is in bright sunlight or a dry environment requires more frequent watering than one that is in the shade or somewhere humid. It is important to adjust the watering frequency based on your plant’s environmental conditions.
Always water with room-temperature water. Cold water can lead to shock and an unhappy plant.
Plant the Calathea in a well-draining soil in a pot with a drainage hole. Adding perlite or orchid bark increases the drainage of the soil.
How to bottom water your houseplants
If your Calathea’s soil is very dry, you can bottom soak the plant to increase moisture (your pot will need to have a drainage hole to absorb the water!).
To bottom water your Calathea:
- Place the pot in a tub of room-temperature water for an hour. Allow the pot to soak up water from the drainage hole.
- After an hour, feel if the water has reached the top few inches of soil. If it still feels dry, water from the top.
- Once the soil is saturated, remove the water from the tub and allow the pot to drain the water thoroughly.
- Once the excess water has been drained, place the pot back in it’s original spot.
Water Quality
Tap water has salts and minerals, which build up in the soil of the plant and lead to the leaves turning brown on curling up. To avoid this problem, use a water filtration system. You can also water with collected rain water, or leave tap water out in an open container to sit overnight before watering so the chlorine evaporates.
2. Brown spots on Calathea due to low humidity
Native to tropical areas, Calathea thrive in humidity. Low humidity is a common cause of brown spots.
Avoid placing the Calathea next to any vents or heaters, as these dry out the surrounding air.
Increase the humidity of the room by:
- Keeping a humidifier next to the plant. This is the best way to increase humidity.
- Misting the air around the plant with a spray bottle (note: do not excessively mist the leaves or leave them soaking wet because it can lead to bacterial disease. The moisture should evaporate off the leaves within a few minutes and the leaves should not remain wet).
- Placing the plant in a pebble tray with water (make sure the pot is on the pebbles, not in the water). As the water evaporates, it increases humidity.
Temperature
Calathea are not fond of the cold weather and can get crispy leaves quite easily. Keep this plant in temperatures from 65 to 80 °F (18 to 30 °C).
3. Brown spots on Calathea due to bright sunlight
Calathea prefer low to medium light. Direct sunlight causes leaf burn, leading to brown spots on the leaves.
If your Calathea is in front of a window, move it farther away or draw a sheer curtain so that it receives indirect light.
Avoid placing the Calathea near south facing windows because they provide very bright light that can be too harsh for this houseplant. East, west or north facing windows are better.
4. Brown spots on Calathea due to pests
Brown patches on the leaves may also be due to pests. Calathea are prone to spider mites, mealy bugs and aphids.
Other signs of infestation include:
- Irregular or stunted growth
- Cotton-white webbing
- Yellow or brown spots
- Black spots or mold like substance
Check your plant closely for signs of insects. If you notice pests, quarantine your plant so that they do not spread to any neighboring plants.
Wash the plant in the sink under a strong stream of water with an insecticidal soap. Spray the plant with rubbing alcohol or diluted neem oil.
Many pests have a long life cycle, so continue to spray once every three to four days until all signs of the infestation are gone. The whole process may take several weeks.
5. Brown spots on Calathea due to disease
Bacterial and fungal diseases can cause leaf spot disease on Calathea. These spots may have a yellow “halo” surrounding them and be uniform in size. Snip off the affected leaves with gardening shears, cleaning the shears between each cut. Check any neighboring plants for signs of disease, as this can be contagious, and keep the Calathea away from other plants.
Prevent bacterial and fungal diseases by keeping Calathea leaves dry. While Calathea are fond of humid conditions, only mist the surrounding air, do not mist their leaves directly. Wet leaves lead to bacterial and fungal diseases that can cause black spots. If you spill water on the leaves, wipe it off with a tissue.
Leaf spot disease can be prevented with good air circulation, well-draining soil, and by not excessively watering. If leaf spot is suspected, use a fungicide, or a home remedy of 1 tablespoon of baking soda and 1 teaspoon mineral oil in a spray bottle of water. Spray this over the infected areas.
What to do about brown leaves
Once your Calathea’s leaves have turned brown, they will not go back to normal. However, if the issue is fixed, the new growth will be healthy and normal and the brown leaves will eventually fall off.
If you want to improve aesthetics, you can cut off the brown leaves or affected portions of the leaves with a clean pair of gardening shears. Do not remove more than 20% of the plant’s leaves at once.
Calathea care summary
| Sunlight | Bright, indirect sun. Avoid excess sunlight as it burns the leaves |
| Water | Keep the soil moist. Water when the top 1 to 2 inches of soil are dry |
| Soil | Well-draining soil |
| Temperature | Warm temperatures with high humidity, 65 to 80 °F (18 to 30 °C) is ideal. Not cold hardy |
| Propagation | Propagated by plant division (but can be difficult to propagate) |
| Toxicity | Non-toxic to pets or humans |
In summary for brown spots on Calathea…
Brown spots on Calathea may be due to:
- Dry soil
- Low humidity
- Excess sunlight
- Infestation by pests
- Bacterial or fungal disease
Remember to keep your Calathea in low to medium light, high humidity, and moist soil for it to thrive.
While the brown spots will not go back to normal, if the issue is fixed, the new growth will be healthy.
See other plant specific care guides here
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