Your peace lily will reward you with graceful white blooms if you take good care of it. However, these lovely flowers can turn brown or black for a variety of reasons.
The browning or blackening of peace lily flowers is frequently the result of improper watering and humidity issues. Botrytis, black rot, ringspot virus, root rot, blight, and leaf spot disease are all exacerbated by these conditions. To save your plant, prune out the affected areas and treat them with fungicide.
Fungus and High Humidity Causes Black Spots on Peace Lily
Peace lilies are members of the aroid family, which includes moist-loving plants. But don’t get me wrong: I’m not a snob. You’ll do more harm than good if you irrigate your plant so frequently that the growing medium becomes soggy.
The same is true if you leave peace lily leaves and flowers damp for an extended period of time. These excessively moist conditions will attract unwelcome visitors: fungi and bacteria.
These fungal and bacterial infections are to blame for the browning or blackening of peace lily flowers.
 Botrytis Blight (Gray Mold)
Botrytis blight is a fungal disease caused by the fungus Botrytis elliptica in peace lilies. However, the fungus Botrytis cinerea can occasionally cause it.
Fungi spores are frequently found in plant debris and are spread by water splashing and irrigation water.
Botrytis is typically favored by overly wet conditions. This is particularly noticeable in the spring when the weather is cool and wet.
It can also happen if you overwater your peace lily, so look for moldy cover on the soil surface.
Small oval-shaped tan to reddish-brown spots on the leaves, flower buds, and flowers are the first signs of the disease.
Spots with lighter centers and purple margins are common. These lesions grow in size, coalesce, and eventually engulf the entire leaf or flower.
Browning, spotting, and wilting are common symptoms of blight on peace lily flowers. Flowers that have been affected may appear to be fading or aging.
Blighted flowers, on the other hand, brown from the inside out, unlike old flowers that do so from the outside.
Buds that are affected rarely open or bloom. The lower foliage and flowers will quickly brown if nothing is done. They’ll turn black, die, and fall off the plant eventually.
Common symptoms of the gray mold include:
- Large fuzzy, dusty, or grayish areas on undersides of leaves
- Grayish or reddish-brown spots on foliage, flowers, and stems
- Peace lily collapse
- Your plant may look droopy, wrinkled, or shriveled
- Leaf and flower drop
Control and Management
Treating your peace lily starts with good sanitation and sound cultural practices:
- Remove and destroy any plant debris and dead matter
- Ensure good horizontal air circulation around your peace lily
- Avoid splashing the leaves when irrigating your peace lily
- Water early in the morning to minimize leaf wetness
- Avoid overwatering or overhead irrigation
Make sure to isolate your peace lily promptly to prevent contact with other plants
Cut out browned, molded, and infected parts of your peace lily. Bag and dispose of them safely. Ensure to wash your hands and disinfect cutting instruments between cuts.
For effective chemical control, use a fungicide labeled for blight (Check the latest price on Amazon here).
 Bacterial Brown Spot
Bacterial brown spot is a disease caused by a variety of Xanthomonas, Erwinia, and Pseudomonas bacteria.
The pathogens survive the winter on plant debris and attach to foliage via water splashes. In cool, wet weather, the disease takes hold of your peace lily.
The infection begins with watery or greasy brown to black lesions. These water-soaked lesions are frequently surrounded by a yellow halo.
They first appear on the undersides of leaves before spreading to other leaves and lily flowers.
Brown spots caused by Xanthomonas are typically v-shaped and extend inwards from the leaf edges.
These necrotic lesions on the flower bracts can be rounded, irregular, or angular. They typically expand and merge, giving the leaves and flowers a wilted appearance.
The bacterial disease is most aggressive on older foliage, but it spreads quickly to younger leaves.
Affected foliage and flowers have a delicate and papery feel to them. If you have a severe infection, your peace lily may defoliate, wither, and die.
Control and Management
Bacterial leaf spot is highly contagious. So sound cultural practices and hygiene will help:
- It would be best to quarantine affected plants immediately.
- Allow the leaves and flower to dry out as much as possible
- Minimize use of overhead irrigation and prolonged foliage wetness
- Sanitize your garden cutting tools, clothes, and wash your hands
If your peace lily has become severely diseased, you may have to remove and destroy it entirely. Otherwise, infected leaves, flowers, and other parts must be pruned and discarded.
Most bactericides work as preventative measures, so if you have a history of bacterial diseases, use them as soon as possible.
Bactericides containing copper sulfate, copper octanoate, or copper hydroxide are my preferred choice.
 Ringspot Virus
Ringspot virus is a type of viral spotting disease that affects papaya, cucurbit, and strawberry plants. It can, however, ambush your peace lily during the flowering stage. As a result, the blooms will become brown or black.
Aphids are the most common vectors of the Ringspot virus. They inject the virus into the vascular system while sucking sap. The virus is rarely fatal, but it can wilt your peace lily’s appearance.
The most common symptoms of the ringspot virus include:
- Distorted, contorted, or malformed leaves and flowers
- Brown streaks on foliage and flowers
- Intense yellow mosaic on the peace lily foliage
- Dark brown blisters on blooms and leaves
- Leaf curling
Treatment of Ringspot Virus
The most effective treatment strategy combines control and prevention. This is due to the fact that chemical controls rarely work on the ringspot virus.
It’s also critical to keep virulent aphids away from your peace lily. If you find them, use neem oil, insecticide spray, or pesticide to get rid of them.
If your peace lily has a full-blown viral infection, it’s best to destroy it. To prevent further spread, disinfect your pruning tools.
 Collar Rot or Southern Blight
Fungal mycelia cause both collar rot and southern blight. If you overwater your peace lily, these soil-borne fungi will often germinate. They quickly spread in stuffy, poorly circulated, and wet environments.
The most common symptoms of collar rot include:
- Rotten, soft, or swollen stems with cankers
- Leaves and flowers may appear dark brown, gray, or purple
- Severe infection may cause leaves to become curled and drop off
If you see collar rot, it’s likely that there’s root rot beneath the soil line. The roots can be soft, mushy, brown, or black. Of course, a distinct rotting odor may emanate from the soil.
The fungus Sclerotium rolfsii causes southern blight. It is a potentially fatal disease that causes the leaves of your peace lily to discolor, yellow, and wither. Other signs and symptoms include:
- Wilted leaves and flowers
- Browned or blackened buds, flowers, and foliage
- Discolored lower leaves
- Defoliation and plant collapse
Control and Management
Southern blight and collar rot are both caused by overwatering, poor drainage, or insufficient air circulation. As a result, you must make appropriate cultural adjustments to prevent and stop the spread.
Garden hygiene can be beneficial. As a result, remove and dispose of all plant matter, debris, and prunings.
Isolate the infected peace lily and remove any affected parts.
Some soil pathogens may be eliminated with the help of sun exposure. Make sure to keep soil temperatures above 122°F (50°C).
Protective fungicide spray should be applied early in the spring season.
 Pythium Root Rot
Pythium root rot is a dangerous disease that can lead to the death of your peace lily. Fungus spores can be found in the debris and soggy growing medium. Wet conditions promote germination and spread as well.
The Pythium fungi will cause your peace lily’s healthy roots to soften, turn brown or black, and die.
Water splashing up from the potting mix can also spread pathogens above the soil line. As a result, stem rot, collar rot, and wilting may occur.
Common symptoms of Pythium root rot include:
- Yellowing and wilting of leaves
- Rooting and blackened roots below ground
- Stems become soft, browned, and weak (stem rot)
- Flowers become distorted, browned, or blackened
- Buds may fail to open
- Leaves become droopy and drop off
- Dieback and browning of leaf tips and shoots
- Stunted growth
Control and Management
- Avoid overwatering or splashing water on leaves of your peace lily
- You must repot your container peace lily to eliminate soil-borne pathogens. Make sure to trim off infected roots, flowers, and leaves before treatment and repotting.
- Treat potting mix with hydrogen peroxide
 Cylindrocladium Root Rot
The fungal disease Cylindrocladium root rot is caused by the fungus Cylindrocladium spathiphyllum.
It thrives in warm, humid conditions with temperatures ranging from 75-80°F (23-27°C). Excess fertilizer may exacerbate the problem.
This disease, like Pythium root rot, can cause collar rot, stem rot, and petal blight. This means that the affected flowers will develop brown spots.
Other common signs and symptoms include:
- Lower leaves become yellowed and wilt
- Roots become soft, browned, and die
- Brown to black leaf spots with yellow halos
Control and Management
Fungal spores are spread through irrigation water. So, water at the base instead of overhead irrigation. Avoid water splashes and wetting the leaves.
Improving ventilation and spacing your plants may help
Reduce relative humidity around your peace lily.
Use a systemic fungicide (Check the latest price on Amazon here) to treat and protect your peace lily
 Septoria Leaf Spot
Septoria leaf spot is a fungal disease that primarily affects your peace lily’s foliage. However, the fungal infection can spread to the flowers and cause browning and spotting. It typically affects overwatered or weak peace lily plants.
Apparent symptoms may include:
- Target-like spots that first appear on lower/older leaves. These circular spots have dark borders and gray centers often with yellow halos.
- Brown spots on blooms
- Affected leaves shrivel, wilt, turn brown and fall off
- Affected leaves usually turn yellow and may dry out
Control and Treatment
Prune out and discard infected foliage and flowers
For organic controls, use copper-based fungicides or those containing potassium bicarbonate
For chemical controls, I find chlorothalonil-based fungicides to be effective.
 Pests on Peace Lily
Brown or black spots or patches on your peace lily could indicate a pest infestation. Some of them may promote the development of black sooty mold on flowers and foliage.
Look out for the following common peace lily bugs:
Symptoms: Aphids can be identified by clusters of pear-shaped green pests on the undersides of peace lily leaves.
They are also capable of invading tender new growths. To make matters worse, aphids may carry viruses such as the ringspot virus or the mosaic virus.
Aphids cause yellowing, curling, and distorted leaves. They consume sap and excrete honeydew, resulting in black sooty mold. This black sticky substance may be found on the foliage, stems, and flowers.
Treatment: Because aphids multiply quickly, early control is critical. Using a cotton swab soaked in 70% isopropyl alcohol, squish or dub some of the colonies.
If there is a large infestation, use a strong stream of water to knock them off, then apply an insecticidal spray.
I prefer to start with neem oil or insecticidal soap spray. To ensure that all aphids hiding in nooks and crannies are eliminated, you must be thorough.
If it doesn’t work, use an acephate insecticide (Check the latest price on Amazon here). Re-apply after every seven to ten days until you rid your peace lily of aphids.
Symptoms: Scales are small hard-shelled bugs that appear as bumps on your peace lily’s foliage and stems.
Because they are sap-suckers, you may notice sticky honeydew. Sooty mold may also smudge the foliage, flowers, and stems.
Treatment: Scrape off some of your peace lily’s scales, then rub them with an alcohol-soaked cotton ball, swab, or cloth.
Controlling a scale infestation during the nymph stage is easier with neem oil, insecticidal soap, or pyrethrin-based insecticide.
Symptoms: Thrips are small black or white bugs that you might see flying around your plant. They lay yellow eggs on the surface of the leaf, but they can also be found on stems and flowers.
Thrips infestation is indicated by silvery gray or brown streaks on leaves and flowers. Other common symptoms include malformed flower buds and splotchy leaves.
Treatment: To remove thrips from your peace lily, use a strong jet of lukewarm water. In the case of kill-sprays, a weekly application of neem oil should suffice. To get rid of the bugs, you can also use yellow or blue sticky traps.
Symptoms: Spider mites are 8-legged sap-sucking bugs that attack peace lilies in hot, dry weather. They do not, however, produce honeydew.
You most likely have a spider mite infestation if you notice curled up, stippled foliage shrouded in soft webbing.
When you shake your plant, they appear as tiny moving dust particles. Spider mites can also be identified by faded flowers speckled with brown or black spots.
Treatment: The application of insecticidal soap or neem oil spray is usually effective against spider mites. You can also take your peace lily outside and spray with a sulfur-based insecticide.
 Excess Sun Exposure
Browned or scorched leaf and flower edges indicate overexposure to direct sunlight. Peace lilies thrive in medium to bright, indirect light. They can even tolerate low light levels as long as they are not in direct sunlight.
Direct sun will sunburn the leaves and flowers. Common symptoms may include:
- Leaf discoloration or bleaching
- Burned leaf tips and edges
- Curled or warped leaves
- Brown spots or streaks may appear on upper leaves and exposed flowers
You must move your peace lily out of direct sunlight. If it’s next to a south or west-facing window, move it away from the window.
 Low Humidity
Peace lilies, once again, prefer high humidity. That is not to say that the leaves should be wet.
Peace lily flowers and leaves will brown at the tips and edges if the humidity is extremely low. This is common indoors during the winter due to central heating.
You may also notice other symptoms like:
- Leaves are dry and crispy
- Wilted leaves
- Leaves may turn yellow
- Remove your peace lily from the path of heating vents and drafts
- Sit your peace lily on a large water tray with pebbles
- Use a humidifier to see to it that your peace lily gets proper humidity
 Natural Aging
Sometimes the flower’s aging process is all that’s going on. When the time is right, the flower will let you know by turning brown.
Tips to Note If You Wish to Ensure Happiness of Your Peace Lily Flowers
Avoid overwatering: Wait until your peace lily is slightly wilting to water again. Minimize overhead irrigation and water splashing. Ensure the soil is consistently moist but not soggy.
Fertilize properly: Fertilizing too often or using a strong fertilizer can cause fertilizer burn. Apply standard water-soluble houseplant feed at half or quarter-strength monthly from spring through summer.
Ensure good sanitation: Remove and dispose of plant debris regularly. Disinfect garden tools after each use.
Provide bright, indirect light.
Give proper blooming temperatures: Keep winter temps between 60-65°F (15 – 18°C) and spring temperatures between 70 – 75°F (21 – 24°C)