Written by Ivy
Feb 15 2023
Black leaves on your prized indoor plants can be rather unsettling. More so on a plant with gleaming, emerald foliage that is renowned for being particularly stunning.
Understanding the cause of this scourge, how to treat it, and how to make sure it never happens again are therefore likely to be high on your list of priorities for houseplants.
What causes the black or browning of peace lily flowers? If the flower on your peace lily is black or brown, it's possible that you've overstressed it or neglected to take care of the houseplant. In addition, as they age, all peace lily flowers turn brown.
In this article, I'll go into much more detail about what might be the reason for this discoloration in your peace lily flower. I'll even discuss how long peace lily flowers typically last and what you can do to perhaps increase your own. Keep reading, as you won't want to miss it!
Even the best of us can be alarmed by a Peace Lily with black leaves, but before you start acting rashly, take a moment to read this article. It outlines all the most frequent causes for this popular indoor plant to produce black leaves as well as what you should do to fix the problem. Infections with fungi and pests both cause the blackening of peace lily leaves or the development of black spots on them.
The pattern or type of discoloration affecting your plant counts when you're attempting to diagnose the cause so it is well worth taking a little time to closely observe your plant for symptoms. This will make it easier for you to comprehend why it has black leaves and what you should do to fix it. Some of the most common symptoms include:
Drought is most frequently to blame for a leaf that has completely turned black over time. Cells of the plant become severely dry due to a severe underwatering.
The moisture in a plant's leaves evaporates during transpiration; if this water is not replenished through routine watering, plant cells become dehydrated, which leads to the desiccation and blackening of the plant's leaves, like the foliage in this picture.
That said, blackened leaves could also be due to a plethora of other factors including:
These issues will normally manifest in the form of not only black leaves, but also brown, or yellow leaves and even the presence of black spots. Here is a rundown of how your Peace lily leaves may present and the likely reasons for that:
The causes of a leaf discoloration of yellow and black may be due to:
Excessive watering: Your Peace lily's leaves could turn black and yellow if you give it too much water.
Lighting issues: Another issue that may cause your plant's leaves to turn yellow with dark spots is direct sunlight exposure. Yellowing – rather than black and yellow leaves – is usually due to insufficient exposure to light.
Pests: Your peace lilies may develop black-speckled leaves that can also turn yellow as a result of spider mites and mealybugs, which are known to attack indoor plants that thrive in humidity.
Typically, brown patches appear first on a Peace lily before the development of black tips. This is most often a result of:
Unfiltered water: The presence of chlorine and other chemicals in tap water can cause peace lilies to become sensitive.
The tips of your plant's leaves could darken if you use unfiltered water on a regular basis. resulting in sharp black edges.
Overzealous fertilizing: Root or foliage burn on your Peace lily could result from fertilizing too frequently or using more fertilizer than is necessary. (Read More: When & How to Fertilize Peace Lilies)
Temperature shock: Your Peace lily might suffer from suddenly dropping temperatures. Your Peace lily's capacity to function properly can start to be impacted by temperatures below 60°F (15.5°C).
Your peace lily might not be able to withstand the cold if temperatures drop even lower, to 45°F (7.2°C), or lower. The blackening of the leaves' edges is one of the symptoms of temperature shock. Leaving it could make the plant die.
Low humidity: Peace lilies thrive in the presence of high humidity. Especially considering that it will cause them to perspire more slowly.
In low-humidity areas, on the other hand, higher transpiration rates will result in darkening leaf tips as more moisture is drawn from the plant into the surrounding air.
Viral , Bacterial or Fungal infections: Due to the procedures used by manufacturers before they are sold, a fresh bag of store-bought potting mix is unlikely to contain any pests or diseases. However, these problems can spread from plant to plant and through soil contamination. As a result, soil is invaded by microbes, which ultimately results in infection.
One such illustration is pythium, which can enter your plant pot through fungus gnats drawn to moist soil.
Once present, it can lead to root rot, which will first darken the plant's leaves. (Read More: Peace Lily Root Rot - Signs & How to Solve)
Root rot is the main culprit of black spots on the roots of your Peace lily. The white roots may darken as a result of overwatering or soggy soil, before acquiring a slimy texture and eventually rotting. (Read More: Overwatered Peace Lily - Signs & How to Revive)
As the condition worsens, black spots will appear on the peace lily's leaves. The plant's stems and leaves will eventually turn dark and mushy if the situation is allowed to continue.
When I'm repotting, I like to look for root rot. Examine the roots to make sure they are firm and white or cream in color by gently brushing off the soil.
Snip away the afflicted roots if you spot any black spots to stop the infection from spreading. To avoid infecting unaffected roots, make sure to clean your cutting tools thoroughly before and after each use. (Read More: How to Repot A Peace Lily)
You can start working on a solution once you've identified the problem's root cause. As you might anticipate, timing is very important. You must act quickly to prevent further delay and to be successful in solving the issue. Read More: How To Grow Peace Lilies Outdoors
Here are detailed steps you can take once you've worked out what the problem is:
When soil is soaked from overwatering, harmful microbes may flourish in it and cause further damage.
This could result in root rot, which could have detrimental effects on your Peace lily.
The important thing is to strike a balance, which can be done by measuring the moisture content of the top 2 inches of soil. Your plant needs watering if the environment is dry.
In order to prevent soggy soil, peace lilies should be planted in containers with adequate drainage holes, which allow excess water to drain freely from the bottom of the container. While I'm watering, I like to stand my pots in the sink so that any extra water drains off instead of collecting in the drip tray.
Doing so will ensure the soil is moist, but not soaked. (Read More: Peace Lily Drooping & Keep Wilting - How to Save)
I stick two fingers into the pot about two inches deep to check the soil's moisture. If it's dry, I know it's time to water. Because their leaves and blooms will droop when they are thirsty, peace lilies are also excellent at letting you know when they need to drink.
Because peace lilies are sensitive to the chemicals in tap water, it is best to water them with distilled or bottled water.
Avoid this by leaving your tap water out overnight to let the chemicals in it dissolve before using it to water your houseplant. Buying bottled water comes with a host of environmental and financial problems.
The soggy roots and saturated soil are hated by peace lilies. This entails only using pots with bottom drainage holes and making sure the soil is completely drained after each watering session.
Since they also dislike dry soil, check it frequently for dryness to prevent the possibility of drought stress.
The tips of peace lilies will start to darken if they are exposed to direct sunlight, which they dislike very much.
It is therefore best to put your houseplant close to windows that get morning sunlight; it should be kept out of the direct path of the light, but close enough to it.
Peace lilies are accustomed to high humidity because they are native to tropical forest regions. Consequently, ambient levels should be kept at 50% or 60%.
Regular misting or even setting the plant on top of gravel that is submerged in very shallow water can help to increase humidity levels.
As an alternative, you could group your plant with other tropical and humidity-loving houseplants so that it can benefit from the moisture those plants exude.
Generally speaking, shade-tolerant species need less fertilizer than other houseplants. Consequently, it is best to err on the side of caution when fertilizing your Peace lily. If you happen to be using fertilizer especially designed for houseplants, the Clemson Cooperative Extension suggests using only a quarter of the suggested amount to avoid overfeeding.
Fertilizer can cause the accumulation of salts in the soil if it is applied in excess. Your peace lily's roots may shrivel up as a result, which will impair their capacity to absorb water and nutrients. As a result of their diminished function, leaves may begin to wilt, yellow, and develop black edges. (Read More: Why Do My Peace Lily Leaves Tips Turning Yellow)
When To Fertilize Peace Lily
In the spring and summer, peace lilies need to be fed every two weeks, and in the fall and winter, they need to be fed every six weeks.
Your leaves' health may be impacted by pests. Some of them such as arachnids or insects can cause them to darken and turn black. More information is provided below on a few of the most frequent offenders who are likely to do just that.
Common Pests On Peace Lily
Mealybugs and spider mites are two common pests you might have to deal with in this regard. In this subsection, I explain how you can identify them, what issues they cause, and how you can rid your floral friend of these arthropod invaders.
Mealybugs are related to scale insects and can be recognized by their long antennae, oval bodies, numerous appendages, and light waxy covering. They originate from the tropics and actually favor perennials, just like your peace lily.
This creepy crawly will eat any part of a plant. They are also prolific breeders; depending on the subset of the species to which they belong, they may either give birth to their young or simply hatch 600 eggs. On your peace lily, a new generation will spawn every 4 to 12 weeks, regardless of the situation.
Mealybugs love plant sap. They can seriously harm crop plants in warmer climates and are also quite voracious. They frequently attack leaves where they meet the stem, causing them to turn yellow and eventually fall off.
Mealybugs not only consume sap, but they also leave honeydew in their wake, which can encourage the development of fungi that cause sooty mold. Mold is usually not harmful, but when it is, it can interfere with photosynthesis.
They look like tiny moving specks at first glance, being relatives of spiders. They enjoy establishing colonies on the undersides of leaves and create a distinct web matting. Tomatoes, melon, and sweet corn come to mind as examples of vegetables they are known to enjoy. They aren't opposed to settling on your peace lily, though.
Spider mites are capable of laying 200 eggs and of rushing through their entire lifecycle in just 7 days. These spiders are also capable of locating and feeding on the cells in your peace lily.
Yellowing, bronzing, and eventually shedding are the results, which may have an impact on your peace lily's general health.
How To Treat A Pest Infestation On Peace Lily
Bug spray may not always work to get rid of these arthropods; in the case of mealybugs, their waxy coverings may provide some defense.
Therefore, it is strongly advised to be vigilant in order to stop these bugs from entering your home in the first place. Especially since they can infect other plants. Every new plant must be inspected thoroughly and only brought indoors once it has been deemed to be bug-free.
In the event of their making it indoors, neem oil is one of your best bets. Remove all observable signs of the pest first, then wipe leaves and stems with a weak solution of dish soap and water. Since most pests prefer to settle down there, pay close attention to stem junctions and the underside of leaves.
After that, spray the Peace Lily with neem oil and wipe all the affected areas with a dry, clean cloth. Once the pest infestation has disappeared, repeat this process.
Rubbing alcohol is also another excellent remedy. Like when using neem oil, you must eliminate all signs of the infestation and wipe down surfaces with a dilute dish soap solution before soaking some cotton in rubbing alcohol. Then dab at affected areas. Wipe away any excess rubbing alcohol to avoid damaging delicate stems and leaves.
Whatever method you choose to use, quarantine your Peace lily away from other plants to prevent potential cross-contamination.
A Peace lily's occasional black leaf after reproduction is not unusual. Overwatering or underwatering due to indifference are the main causes of this.
Remember to avoid fertilizing your plant until it has begun to grow new shoots, and to keep the soil of your propagated plant moist but not soggy. This is an indication that your plant is established and has developed a healthy root system.
Be sure to use new potting soil to plant your propagated plant. This will provide peace of mind that your plant has sufficient nutrients for roots to get thoroughly established.
With the exception of moving the peace lily's entire body intact into a new home, repotting is very similar to propagating.
To avoid the possibility of leaves turning black, avoid fertilizing and always plant in fresh potting soil.
The duration of a peace lily's bloom is between four and eight weeks. After that, they wilt and become darker. You will then need to prune them right at the base. Doing so will enable your peace lily to be able to sprout new flowers. (Read More: Why Is My Peace Lily Not Blooming)
Wilted or broken leaves must also be pruned as well to reduce stress on the plant and enable it to direct its resources to healthier growth.
Blackened leaves need to be pruned right away. Your pruning shears will benefit from a dip in disinfectant after each removal because there may be a risk of infection. Once you're done, there will be room for new growth to enhance the appearance of your plant.
Now that you know more about the peace lily's typical life span, you might be wondering how long you will get to admire that lovely white flower. On Peace lilies, the flowers bloom for approximately 10 days, and the spadix generally lasts for about a month before it completely withers.
As I'll discuss in the section after this, it is possible to extend the spadix's lifespan.
Your peace lily plant is not necessarily dead or dying if just one of its flowers dies. The peace lily has a three to five year lifespan on average. Read More: Why Is My Peace Lily Dying - 5 Reasons & How to Revive
But you shouldn't leave a dead spadix on your peace lily for an extended period of time. In particular, because the texture of the stem can be challenging after flower death, use a pair of clean pruning shears for removal.
Don't try to take the dead peace lily flower right off with your hand, as this can cause unnecessary stress on the plant
Slice the stems off of your peace lily at the base. Cut off the affected leaves as well if you see any leaf discoloration, such as browning, yellowing, or blackening.
The best way to avoid black spots on Peace Lily leaves is to give the plant the proper care.
Here are some tips to help you keep your peace lily healthy and free of black spots:
Think about which one of the following—drought stress, excessive watering, high temperatures, low humidity, excessive fertilizing, exposure to sunlight, or use of chlorine-containing water—could be the cause of your Peace lily's blackened leaves. To assist you in determining the issue's root cause, use the symptom checker at the top of this article.
Your plant's longevity, quality of life, and ability to produce glossy, green leaves for an extended period of time will all be improved by keeping the proper balance of environmental conditions that Peace Lilies require while also performing routine inspections of your plant.