Brown leaves on a Maranta can be a sign of various issues, such as improper care, watering, or environmental factors. Here are some common reasons for brown leaves on Maranta plants and how to address them:

1. Under-watering or over-watering: Marantas prefer consistently moist soil but do not tolerate waterlogged conditions. If the soil is too dry or too wet, it can cause leaf browning. To fix this issue, establish a consistent watering schedule. Water your Maranta when the top inch of the soil feels dry to the touch, and ensure the pot has drainage holes to prevent waterlogging.

2. Low humidity: Marantas thrive in high humidity. If the air around your plant is too dry, the leaves may turn brown and crispy. To increase humidity, you can:

• Place a tray filled with water and pebbles under the pot, ensuring the pot doesn't touch the water directly.
• Mist the leaves regularly with distilled or filtered water.
• Use a humidifier near the plant.
• Group your Maranta with other humidity-loving plants to create a microclimate.

3. Nutrient deficiency or excess: A lack of essential nutrients or over-fertilization can cause leaf browning. Marantas require a balanced, water-soluble fertilizer diluted to half strength every four to six weeks during the growing season. If you suspect over-fertilization, flush the soil with water to remove excess salts and adjust your fertilizing routine.

4. Exposure to direct sunlight: Maranta plants prefer bright, indirect light. Direct sunlight can scorch the leaves, resulting in browning. Move your plant to a spot with filtered light or provide a sheer curtain to protect it from harsh sunlight.

5. Temperature fluctuations: Marantas are sensitive to extreme temperature changes and drafts. Maintain a consistent room temperature of 65-80°F (18-27°C) and avoid placing your plant near vents, heaters, or drafty windows.

6. Pests or disease: Pests like spider mites or diseases like fungal infections can cause browning leaves. Inspect your Maranta for signs of pests or disease, and treat accordingly with insecticidal soap, neem oil, or other appropriate measures.

To prevent future issues with brown leaves on your Maranta, ensure you provide proper care, including consistent watering, adequate humidity, and the right light and temperature conditions. Regularly monitor your plant for any signs of distress and address issues promptly to maintain a healthy Maranta.