Peace lilies (Spathiphyllum) are sensitive to excessive moisture. Overwatering can lead to root rot, which restricts the plant's ability to absorb nutrients and oxygen. As a result, the leaves may turn brown, starting from the tips or edges. Ensure the pot has drainage holes and use well-draining soil to prevent waterlogged conditions. Allow the top inch of soil to dry out before watering again.
While peace lilies prefer moist soil, prolonged dryness can also cause browning leaves. If the plant is consistently underwatered, the leaves may wilt and develop brown, crispy edges. Additionally, peace lilies thrive in high-humidity environments. Low humidity, especially in air-conditioned or heated rooms, can lead to leaf browning. Mist the leaves regularly or place the plant on a humidity tray to maintain adequate moisture levels.
Peace lilies are shade-loving plants native to tropical rainforests. Direct sunlight can scorch their leaves, causing brown patches or yellowing followed by browning. Place the plant in bright, indirect light, such as near a north-facing window or behind a sheer curtain. Avoid prolonged exposure to harsh afternoon sun, which can damage the foliage.
Peace lilies are sensitive to chemicals like chlorine, fluoride, and salts found in tap water. Over time, these can accumulate in the soil, leading to brown leaf tips. Use filtered or distilled water for watering. Similarly, overfertilization can cause salt buildup, burning the roots and resulting in brown leaves. Fertilize sparingly (once every 6-8 weeks during growing season) and flush the soil occasionally to remove excess salts.
Extreme temperatures—either too hot or too cold—can stress peace lilies, causing brown leaves. Avoid placing the plant near drafts, air vents, or heaters, as sudden temperature fluctuations can harm it. Ideal temperatures range between 65–80°F (18–27°C). Cold drafts below 55°F (13°C) can cause chilling injury, manifesting as brown spots or edges.
Pests like spider mites, mealybugs, or scale insects can weaken peace lilies by sucking sap from the leaves, leading to brown, yellow, or speckled foliage. Inspect the plant regularly, especially under the leaves, and treat infestations promptly with insecticidal soap or neem oil. Isolate affected plants to prevent pests from spreading.
Older leaves on peace lilies naturally turn yellow and brown as they age and die off. This is a normal part of the plant's lifecycle. Prune these leaves at the base to encourage new growth and maintain the plant's appearance. However, if multiple leaves are browning simultaneously, investigate other potential causes.
A lack of essential nutrients, particularly nitrogen, magnesium, or iron, can cause peace lily leaves to turn brown or yellow. Nitrogen deficiency often shows as uniform yellowing, while magnesium deficiency causes yellowing between leaf veins. Use a balanced, water-soluble fertilizer to address deficiencies, but avoid overapplication.
