Brown Spots on Peace Lily (Causes And Solutions)


Indoor peace lily showing brown spots symptom

Peace lily (Spathiphyllum) is an indoor plant that’s generally easy to care for and maintain. However, one common problem you’ll encounter with this plant is the brown spots that appear either on its leaves or its spathe (white bract surrounding the spadix). 

The presence of these brown spots speaks about the general health of the plant and it’s something you can hardly ignore. 

Brown spots on peace lily occur primarily as a result of changes in the environment making certain conditions unfavorable for the plant’s growth. It may also be caused by some malpractice in caring for the plant. It can be due to the damages by harmful microorganisms or pets that infest the plant. 

To identify the main reason for your peace lily’s brown spots, below are detailed discussions on the possible causes and how to find solutions for each. 

How to Identify Peace Lily Brown Spots

Brown spots can appear either in the leaves or the flowers of your peace lily. At times, they appear in both. 

First off, you have to identify where these brown spots are located. Then, describe how these brown spots appear. By doing so, you’ll be able to figure out what causes the problem using a simple diagnosis.

Peace Lily Brown Spots on Leaves

It’s very common for us to see brown spots on the leaves of our plants. Sometimes, we have the tendency to just ignore it. However simple as it may seem, you should consider brown spots as a red flag.

Brown Spots And Streaks on The Leaf Surfaces

Brown spots and streaks on the leaves indicate that your peace lily is receiving too much light. Direct exposure to high light intensity can lead to scorching of the leaves. 

The burnt areas would create brown spots. If your peace lily is under direct exposure to sunlight, then the browning must be caused by it. 

Browning On Leaf Tips or Margins

This is a sign that your peace lily lacks water, lacks humidity, or is over-fertilized. With a very little amount of water channeled within the plant cells, the farthest parts of the plant no longer receive water. 

With low humidity, the air gets very dry making it difficult for your peace lily to absorb additional moisture from the air. Their dehydrated condition leads the cells to shrink and die. 

Too much fertilizer also leads to burnt tips. The salt builds up in the soil creating a drought condition for your peace lily making water less available to the plant. 

Browning At The Base of The Plant, Older Leaves Or Petioles 

When the leaves at the base of your peace lily have brown spots, it can possibly be caused by overwatering, root rot, or fungal problems. Older leaves often show these signs because they’re close to the roots and soil.

Older leaves that turn brown and are squishy when pinched due to overwatering. When you try to pull the plant out of its pot, you’ll notice that the base is weak and rotten. 

Root rot occurs when there’s waterlogging in the soil. This prevents the roots to respire due to lack of oxygen gas leading to its death. 

Another possible reason for the browning of leaves is a fungal problem. One example is the Cylindrocladium spathiphylli which causes root and petiole rot in peace lily. 

Peace Lily Brown Spots on Flowers

Brown spots not only appear on the leaves but on the spathe as well. The discoloration is very prominent because the spathe of peace lily is color white. Naturally, the appearance of brown spots can suddenly bring you to panic. 

Browning of Mature Bloom in Middle Including Stem

This kind of browning is a result of a natural process called aging. It means that the flower is reaching its end.

Generally, a peace lily flower can last around five to six weeks. At this stage, you should expect the brown spots on peace lily flowers and consider it normal.

Browning of Young Bloom Cause It to Never Open

If your young blooms start turning brown and you never see it open, then it’s possible then there is a lack of humidity within your home. A less humid environment inhibits the blooming of a peace lily. 

Brown Spots Appear On the Spathe As Lesions

If pests infect the peace lily, they can cause brown spots on the plant. Some unwanted organisms love to chew the plant tissue to suck up the sap. 

As a result, they leave lesions on the surface. Whenever you see brown spots, always check for any presence of pests in the plant. 

What Causes Brown Spots on Peace Lily Leaves 

Once you’ve identified where the brown spots are and how they appear in your peace lily, identifying the cause is no longer difficult. The type and location where these spots appear are often related to the cause behind. 

Excess Light

Peace lily requires moderate indirect light. It can even tolerate low light levels. So you can understand that exposure to bright light levels will create a problem. 

They’re pretty sensitive to strong intensities of light so it’s important to keep that in mind when finding a location for your peace lily.  Now, here are some tips about ensuring proper lighting.

Mind the season 

There are different light conditions in every season. During summer, light is abundant because the sun is always shining while in winter, sunlight is deficient.

During days of abundant light, don’t place your peace lily in a location where it’s too bright. Make sure it’s 10 to 15 feet away from the window so that it receives a moderate amount of light. 

Provide Shade

An 80% shade is necessary to make an ideal light condition for a peace lily. This is to produce a filtered light during summer. You can use curtains to filter the direct lights.

In winter, shading can be adjusted to 70% since the light level is relatively lower. Shades serve as a barrier protecting your peace lily from harsh light intensities. 

Use Artificial Light

Peace lily will also do well even if your room doesn’t have a window. All you need is to provide an artificial light source.

Generally, a fluorescent bulb is enough to sustain the growth of plants. But if you want to encourage blooming, you have to use plant growing light that will provide a red wavelength. 

Place your peace lily under the light source with a distance of at least 12 inches.

Temperature and Humidity

Temperature and humidity are also factors why peace lily develops brown spots. High temperatures and dry air can lead to plant dehydration. It can also cause the curling of your peace lily leaves.

Severe dehydration will lead the plant cells to shrink and you’ll observe that your peace lily wilts. This is then followed by drying up of the plant, browning, and then death. 

Tips on How to Cope with Temperature and Humidity Changes:

Be Aware of Drastic Temperature Changes

It’s not difficult to predict the temperature the next day so it’s better for you to be aware in advance. Is it going to be too hot tomorrow? 

That way, you’ll have enough time to prepare and move your plants somewhere safer. Temperature varies from day to day so there are times when you need to relocate your plants to avoid so much heat.

Avoid Hot or Cold Drafts

Window glasses tend to radiate the heat. If your plant is close enough to touch the glass then the heat can burn the leaves or the blooms. 

Intense cold can also lead to sudden browning and brown spots of the foliage. Make sure you place your peace lily somewhere far from these drafts. 

Increase Humidity At Home

As a tropical plant, peace lily requires high humidity. To maintain such a condition, you have to exert extra effort in raising it with a few tricks.

Misting is one of them. Use a spray bottle to mist off your plant daily to moisten the air. You can use a humidifier for this purpose.

Another trick is to group your peace lily with other tropical plants. This encourages mutual benefit as another plant can trap the moisture given off by the other. 

Lastly, you can make use of pebble trays. Set your potted plant on top of the tray that’s half-filled with water and let the water evaporate. 

Pest Infestation

Another reason why peace lily develops brown spots is the presence of pests. The common unwanted visitors include scales and mealybugs. Although peace lily is not that vulnerable to pests, we cannot discount the threat they bring. 

Tips on How to Get Rid of Pests:

Natural Control

When the number of pests is minimal, you can employ natural means to control them. You can introduce beneficial predators to prey on them. 

Lady beetles feed on scales so having them around will prevent multiplication of the pest. Ladybugs, lacewing, and the mealybug ladybird (Cryptolaemus montrouzieri) are the predators of mealybugs. 

Mechanical Control

One simple way to get rid of pests is by removing them from the plant parts one by one. This is your first option if the pests present are very minimal and manually removing them is an easy task.

Another way to deal with pests using mechanical means is pruning. You can cut off infected parts such as leaves and blooms to avoid the pests from spreading. 

Chemical Control

The last option you have is to apply chemicals to kill the pests. There are organic and inorganic pesticides available out there. 

Another option is to do DIY solution using a mixture of insecticidal soap, neem oil, and water. You can spray this solution to the infected parts of the peace lily. 

Wiping off your peace lily leaves with cotton balls treated with alcohol is also another simple way to deal with mealybugs and scales.

Bacterial Leaf Spot Disease

Bacterial leaf spot is a pathogenic disease on peace lily commonly occurs on leaves. This can be caused by bacteria Xanthomonas campestris pv. dieffenbachiae, Pseudomonas cichorii, Erwinia carotovora subsp. carotovora and E. chrysanthemi.

Infection happens when the soil is contaminated debris that’s been previously contaminated. These bacteria can also be transferred through water splashes or even air. 

Tips to Prevent Diseases Caused by Bacteria:

Use Sterilized Soil

Sterilizing the soil would help kill the disease-causing pathogens. Using healthy soil would lead to healthy plants. By sterilizing, you’re reducing the number of harmful bacteria present in it. Read this article on peace lily soil to learn more.

Sterilized soil is available in garden stores but you can also do it on your own. You can microwave, bake, or steam the soil for at least 30 minutes at a temperature of 82°C (180°F) or above. (Source: ScienceDirect)

Avoid Watering At Night

A moist environment is favorable for the growth of pathogens. This condition will lead the bacteria and fungi to multiply dramatically. To avoid a prolonged moist environment, you have to avoid watering in the evening. 

Avoid Overcrowding of Plants

Bacteria can travel a short distance via air. If your plants are close to each other, the transmission will be fast. If you’re not sure about the health of your plant, it’s better to keep them away from the rest.

Disinfect Your Tools

Pathogens can also be transmitted through tools. Make sure that you treat your tools after you use them. The least expensive you can use is a chlorine bleach solution to the tools.

Fungal Leaf Spot Disease

Fungal leaf spot is likewise caused by pathogens. The common pathogens that cause this disease are Alternaria alternata, Cercospora species, Colletotrichum species (anthracnose), Myrothecium roridum. Fungal leaf spots appear almost the same as bacterial leaf spots(Source: University of Massachusetts Amherst)

To avoid infection by these disease-causing pathogens, employ the same tips we’ve enumerated above. 

Rust

Rust is also a fungal infection. Infected leaves will initially have chlorotic appearances but as they produce spores, the damaged portions can also look like brown spots.

Dealing with rust is almost the same as dealing with other fungal infections. Make sure to follow the tips mentioned earlier.

Fertilizer Problem

We’ve mentioned earlier that excessive fertilizer leads to browning of leaf tips. Fast-release fertilizers make nutrients readily available for plant’s consumption but too much of it will build up salts in the soil. Peace lily won’t need much fertilizer so you have to control its application.

Tips on How to Fertilize a Peace Lily:

Timing Of Application

Apply fertilizer during spring and summer with an interval of 6 weeks. Active growth happens during these seasons so your peace lily will be able to utilize the nutrients you feed. 

Types of Fertilizer To Use

Use a balanced household fertilizer for healthy peace lily foliage. You can choose between organic and inorganic products. 

To encourage blooming, use a fertilizer that has higher phosphorus content. Whatever fertilizer you use, always make sure to follow the instructions in the package.

Inconsistent Watering

Improper watering is often a cause of many problems in plants. Too much or too little water can both lead the peace lily to develop brown leaves as well as brown spots. To avoid such problems, you need to water your peace lily in a manner that will make it happy. 

Tips on How to Water Peace Lily:

Keep The Soil Moist But Not Soggy

This means that you need to water the plant before the soil completely dries out. But, never allow the pot to sit on the water for too long. 

Adjust Watering Needs Depending On The Season

Hot seasons call for more water. Cold seasons would mean less water intake. You have to adjust your watering depending on how hot or cold the environment is. 

Water Quality

Aside from improper watering, the water quality is also another reason why your peace lily is developing brown spots. Water that’s high in chlorine and fluorine content can be toxic to the plant. 

As a result, the leaves will have necrotic veins and scorched tips. Peace lily is sensitive to fluorine so you have to be careful with the water you use. 

Tips on How to Avoid Water Toxicity:

Using Rainwater

This is still the best option you have for plants. Once you have the chance, collect rainwater in a barrel or any big container. This will help you supply the water needs of your plants. 

Let The Water Sit For 24 Hours Before Using Them

Municipal water is the common option we have in the absence of rainwater. This is fine to use but you have to give it a day of rest to evaporate the chlorine. After that, it’s safe to use.

You May Also Enjoy: Cactus Soil for Peace Lily (And How to Make Your Own)

How Do You Treat Brown Spots on Peace Lily?

Treating peace lily brown spots is the next challenging job you have to face. There are different ways to stop these brown spots from harming your plant. Each solution depends, of course, on what causes it. 

Remove The Infected Leaves

In some cases, removal of the infected portions is enough to get rid of the brown spots. For the aged leaves and blooms, this definitely is a must. The same goes with the ones severely infected with pests. 

Maintain Proper Growing Conditions

This includes adjusting to changes in light, humidity, and temperature. These factors are often uncontrollable but you can make ways to help your plant cope with it. The goal is to maintain the environment as close to the basic growing conditions.

Adjust Water And Fertilizer Application

Too much or too little of these will harm your peace lily. You should know exactly when the plant is thirsty and/or hungry. Give water and fertilizer at the right time with the right amount. 

Treat With Fungicides, Bactericides

Disease-causing pathogens are difficult to get rid of once they’re in. In this case, treating the soil or your peace lily plant itself may be necessary. When using chemicals to control the disease, be sure to follow the recommendations in its label. 

FAQs

Why is the flower on my peace lily turning brown?

Browning peace lily blooms can mean a lot of things. It may be a result of aging, lack of humidity, pests, or disease-causing pathogens. Identifying the real cause would require careful observation of the symptoms. 

Should I cut the brown flowers off my peace lily?

It depends on what causes the browning. If it’s aging, then, you can wait until the blooms are no longer pleasant before you remove them. If the reason for browning is due to diseases, then it’s wise to cut them off immediately. 

Should I cut the brown tips off my peace lily?

Generally, it’s safe to leave the brown tips of your peace lily if it’s not caused by a disease. However, you also need to consider your aesthetic preference. If you wish to cut them off, then, by all means, do so. 

Arifur Rahman

I'm the owner of gardenforindoor.com. After completing my bachelor of science in agriculture, I'm serving as a civil service officer at the Department of Agricultural Extension, Bangladesh. I started Garden For Indoor to make your indoor gardening journey easy and enjoyable.

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