Peace lilies are beautiful, low-maintenance houseplants. They love moisture and thrive in high humidity. They come from rainforest habitats and need warm, consistent temperatures. Keep them away from drafts like windows and air conditioners to avoid fluctuating temperatures.
Just as important as providing enough water is avoiding too much water. Soggy soil deprives the plant of oxygen and encourages fungal growth and root rot.
Watering
Peace lilies need plenty of moisture to keep their lush leaves shiny and green. They evolved to grow on rainforest floors and need high humidity conditions.
When the roots absorb water from the soil, it is used to create energy for the plant through a process known as photosynthesis. The water reaches the leaf tips last, so they will be the first to brown if the plant is too dry.
Overwatering can cause the leaves to brown and rot the root system. This often happens when a plant is placed in a pot that is too large. The extra soil holds too much water and can lead to oversaturation.
If the roots become soft and mushy, they can harbor the fungi that causes root rot. In this case, the plant should be removed from its container and repotted in fresh potting mix. When repotting, the old soil should be discarded to remove any traces of the fungus.
Light
Peace lily brown tips usually occur because of under or over watering as well as low humidity conditions. Since the plant is native to rainforest environments they require warm and humid conditions to thrive. The problem is most common during winter as indoor heating dries the air and this saps moisture from the leaves and roots of the plant.
Keeping the plant away from drafts and windows that can cause sudden temperature changes will help to minimize the problem. Humidity levels are best increased by placing the plant on a saucer filled with pebbles and water which will create a humid micro climate and mimic the plants natural tropical environment. Misting the plant daily will also increase humidity.
Always check the soil before watering and ensure that the water drains out of the drainage holes. If you have to water more than once a week, do it from the top to flush out excess salts that may be accumulating in the soil.
Temperature
Generally, the most common cause of peace lily brown tips is inadequate watering. This leads to stress that causes plant cells to dehydrate and die.
To avoid this, always use room temperature water to water your peace lily and never allow standing water to collect in any saucers or drip trays. Also, keep it out of direct sunlight to prevent sun scorch which will start on the leaf tips and can spread to the rest of the leaves.
It also helps to mist the plant daily. This creates a humid micro climate around the plant and mimics its natural tropical environment. Also, scale back the amount of fertilizer you use. This will help to dilute the salts that accumulate with frequent applications and also prevents brown tips. Only use a general houseplant fertilizer at half strength in spring and summer during active growth. Use a soil meter or your fingers to check the potting mix for moisture. If the top 2 inches of the soil feels wet, you need to repot your peace lily to improve the drainage and moisture in the potting mix.
Humidity
Peace lily plants are moisture lovers and appreciate an aerated soil that is consistently moist but doesn’t remain wet for extended periods. When the soil is too dry, it stresses the plant and causes the leaf tips to turn brown. It may also be caused by too much direct sunlight that scorches the leaves.
Too little water is another common cause of brown tipping in peace lilies. It can be hard to tell how much to water them as they don’t need very much but too little will also cause the leaves and flowers to brown.
Make sure that any saucers or drip trays are empty so that the roots don’t sit in standing water. This is especially important in winters when the plant is indoors and the air can be very cold or dry from heating. Too much fertilizer is also a problem for peace lily plants that can burn the leaf edges and limit the plant’s ability to uptake nutrients.