With their glossy green foliage and graceful white spathes, peace lilies are a favorite houseplant for many enthusiasts.
Unfortunately, they’re picky when it comes to their care.
Changes in their routine or something off in their environment can cause unsightly brown spots to appear throughout the plant. These must be properly addressed if your peace lily is to recover well.
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Why does my peace lily have brown spots?
The most common causes of brown spots on peace lilies are environmental stresses, such as over or under watering, sunlight that is too strong, or fluctuations in temperature or humidity. It may be necessary to remove badly damaged leaves, but correcting the plant’s environment will usually prevent any further brown spots.
Watering
Peace lilies are finicky about how much water they get, and both over and under watering can result in brown spots.
Overwatering
Peace lilies hate wet feet, and too much water is one of the most common causes of brown patches on the leaves and stems. If your lily is looking sickly, check the water levels first.
If it’s potted in a planter without drainage holes, or if the potting soil feels soggy hours after watering, your plant is getting too much water.
Make sure the drainage holes are clear, and if your planter sits in a saucer, empty it of any standing water. Don’t water your plant again until the top two inches of soil feel dry. When you do water, soak the soil, then drain thoroughly.
Underwatering
The symptoms of underwatering closely resemble those of overwatering! Rather than looking at the plant, which in both cases can look limp, with brown and yellow spots especially along the edges of leaves, check the soil for signs of underwatering.
Soil that’s gotten too dry will pull away from the sides of its pot so that even when water is added, the liquid simply runs down the sides of the pot and drains away without reaching the plant’s roots.
The soil may also be overly compacted, making it even harder to water.
To deal with underwatered plants, gently loosen up the soil and water lightly but repeatedly over the course of several minutes to give the water time to soak in.
Once the soil is thoroughly soaked, let it drain, then water again once the top two inches of soil are dry.
Lighting
Most plants aren’t too particular about their lighting as long as they get enough, but peace lilies have their specific preferences.
Too Much Light
Peace lilies prefer indirect light, so a plant parked in front of a window might begin to look brown or bleached. Move your plant out of direct rays, but keep it in a place where it can still catch some diffused light early in the morning or late in the day.
Too Little Light
One of the reasons that peace lilies are so popular as houseplants is their ability to thrive with little light. In fact, they can get along quite well even in office environments with nothing but fluorescent lighting to work with. But too little light can take its toll.
If your peace lily doesn’t bloom and the foliage begins to turn yellow or brown, it’s likely kept in the dark too often.
Move it to a brighter location, but be sure to avoid direct sunlight, as plants moved from dark locations to excessively bright ones will suffer even worse “sunburn” than plants better acclimated to the light.
Other Environmental Fluctuations
Peace lilies are generally easy-to-care-for houseplants, though they’re a bit like Goldilocks—they like their environments just right.
Excessive Cold
While they’re tolerant of warm environments, peace lilies do not like cold! Drafts can quickly cause leaves to wilt and brown at the tips, so make sure your plant is kept away from drafts and cold surfaces like frosty windows.
A good rule of thumb for peace lilies is how comfortable you would find a location. If you’re okay with it, they’re typically okay with it.
Humidity Fluctuations
Peace lilies may not like to sit in water, but they do appreciate a somewhat humid environment. Air that’s too dry leeches moisture from the plant’s leaves, which can make them curly and crispy.
Prevent this by setting your peace lily’s pot in a pebble-filled saucer and adding water to the saucer. The pebbles will help keep the pot above the water, preventing it from getting soggy while still providing a source of moisture for the air around the plant.
Alternatively, you can try misting your plant’s leaves, but this can attract dust and pests, so opt for the evaporative method first if possible.
Chemical “Burn”
Peace lilies are sensitive to certain chemicals in their water and soil, and unfortunately these include common water treatments such as fluoride and chlorine.
To avoid causing yellowing and browning of the leaves, opt for distilled water for watering your plant.
Dilute any fertilizers used to ⅓ or ¼ their recommended strength, as peace lilies are not heavy feeders. If you use potting soil with fertilizer mixed in, soak the soil after repotting and let it drain completely, then repeat the process again once the water stops dripping. This will help remove newly dissolved fertilizer salts and make sure your plant isn’t stuck in too rich an environment.
Pests and Disease
While they might be finicky about their environments, peace lilies are remarkably resistant to disease and pests. It’s unlikely that these are the cause of damage to your plants unless there’s a very severe infestation of pests like mites or mealybugs. If you do suspect these pests, a treatment with insecticidal soap works wonders.
Frequently asked questions about Peace Lily diseases
What do I do about leaves with brown spots?
If your peace lily has unsightly leaves, cut them away at the base of the plant and remove them. Make sure to disinfect your scissors or shears between cuts, and especially between plants. Peace lilies are hardy, but it’s easy to accidentally spread pests or diseases.
When will my peace lily bloom again?
Recovering after stresses can keep your plant from blooming for a time, but once you’ve corrected your lily’s environment and cleared away damaged foliage, you should start to see improvement. If your plant appears otherwise healthy but still isn’t blooming, move it to a brighter location, though be sure to keep it out of direct sunlight.
Daniel has been a plant enthusiast for over 20 years. He owns hundreds of houseplants and prepares for the chili growing seasons yearly with great anticipation. His favorite plants are plant species in the Araceae family, such as Monstera, Philodendron, and Anthurium. He also loves gardening and is growing hot peppers, tomatoes, and many more vegetables.