Black leaves on your prized indoor plants can be rather unsettling. Moreso on a plant known for being especially beautiful, and for having gleaming, emerald foliage.
So, understanding why your Peace lily’s leaves have been affected by this scourge, and what you can do to fix it, as well as ensure the like never occurs again is bound to be high up on your list of houseplant priorities.
Black Leaves On Peace Lilies
A Peace Lily with black leaves can set alarm bells ringing for the best of us but before you start taking drastic action, take a minute to read this article. It covers all the most common reasons this houseplant favorite might be producing black leaves and exactly what you need to do to fix it.
By the way, our site is supported by visitors like you. Some links on this page may be affiliate links which means if you choose to make a purchase, I may earn a small commission at no extra cost to you. Thanks for your support! You can find out more here.
What Causes The Leaves Of A Peace Lily To Turn Black
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 help you better understand the reason why it has black leaves and what you need to do to fix it. Some of the most common symptoms include:
Black Leaves
A leaf that has completely turned black over time is most often due to drought. A severely underwatered leads to a lack of water in the plant’s cells.
The moisture in the plant’s leaves evaporates during transpiration, where this water is not replaced through regular watering, plant cells become dehydrated resulting in the subsequent desiccation and blackening of its leaves just like the foliage in this image.
That said, blackened leaves could also be due to a plethora of other factors including:
- Excessive or insufficient watering
- Disease via infection
- Lighting issues
- Pests
- Unfiltered water
- Over-fertilizing
- Temperature shock
- Low humidity
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:
Leaves Turning Black And Yellow
The causes of a leaf discoloration of yellow and black may be due to:
Excessive watering: Providing water in excessive quantities may result in your Peace lily’s leaves turning yellow and black.
Lighting issues: Direct exposure to sunlight is another problem that can see your plant’s leaves to turn yellow with dark spots. Yellowing – rather than black and yellow leaves – is usually due to insufficient exposure to light.
Pests: Spider mites and mealybugs which are known to attack humidity-loving indoor plants can also cause your peace lilies to have black speckled leaves which can also turn yellow.
Peace Lily Leaves With Black Tips
A Peace lily that has developed black tips is usually preceded by symptoms of brown patches first of all. This is most often a result of:
Unfiltered water: Peace lilies are sensitive to the presence of chlorine and other chemicals in tap water.
Continuous use of unfiltered water can cause the tips of your plant’s leaves to darken as a result. Leading to crisp black edges.
Overzealous fertilizing: Fertilizing too often or using more fertilizer than is required, may cause your Peace lily to suffer root or foliage burn.
Temperature shock: Suddenly plummeting temperatures can give your Peace lily a nasty shock. Anything below 60°F (15.5°C) can start affecting your Peace lily’s ability to function effectively.
Should temperatures fall further to 45°F (7.2°C) or below, your peace lily may not be able to handle the chill. One of the signs of temperature shock is the blackening of the leaves from the edges. If left the plant may not survive.
Low humidity: Peace lilies thrive in the presence of high humidity. Especially since it will slow their rate of transpiration.
The reverse is the case in areas with low humidity where increased rates of transpiration will lead to darkening leaf tips as more moisture is drawn from the plant into the surrounding air.
Viral , Bacterial or Fungal infections: A fresh bag of store-bought potting mix is unlikely to contain any pests or diseases thanks to the processes used by manufacturers before they are sold. However, these issues are transmissible from plant to plant and through cross-contamination with other soil. This causes microbes to invade soil, which eventually leads to infection.
One such example is pythium which can find its way into your plant pot by way of fungus gnats that are attracted to damp soil.
Once present, it can cause root rot which in turn will darken the leaves of the plant first.
Black Spots On Peace Lily Roots
Root rot is the main culprit of black spots on the roots of your Peace lily. This itself is due to overwatering or soggy soil and can result in those white roots darkening before taking on a slimy texture and ultimately rotting.
The peace lily’s leaves will display black spots once the condition is more advanced. Should it progress further, the stems and leaves of the plant will darken and become mushy in texture.
I like to check for root rot whenever I’m repotting. Simply brush off the soil gently and check to see that the roots are firm and white or cream-colored.
If you notice any black spots, snip away the affected roots to prevent the spread of infection. Make sure that you disinfect your cutting tools before use and after each cut to prevent unaffected roots from becoming infected.
Reasons for Black Leaves on Peace Lilies And How To Fix
Once you’ve ascertained the cause of the issue, you can move on to being able to fix it. As you would expect, timing is crucial, as is moving promptly to avoid further delay and being successful in resolving the problem.
Here are detailed steps you can take once you’ve worked out what the problem is:
Overcoming Watering Issues
Overwatering can result in drenched soil which can, in turn, cause harmful microbes in it to thrive.
This could give rise to root rot which can have serious consequences for your Peace lily.
The key here is a balance that can be attained by checking the upper 2 inches of the soil for moisture. If it is dry, then your plant will need watering.
Peace lilies need to be planted in a pot with good-sized drainage holes as this allows excess water to drain freely from the bottom of the pot and will help to prevent soggy soil. I prefer to stand my pots in the sink while I’m watering so that all the excess water drains off rather than pooling in the drip tray.
Doing so will ensure the soil is moist, but not soaked.
How Often Should You Water A Peace Lily?
I test the moistness of the soil by placing 2 fingers about 2 inches deep into the pot. If it’s dry then I know it’s time to water. Peace lilies are also great at letting you know if they need a drink because their leaves and blooms will droop when they’re thirsty.
Using Distilled Or Bottled Water For Peace Lily
Peace lilies are sensitive to the chemicals in tap water meaning distilled or bottled water is a better option when watering them.
Buying bottled water throws up all manner of environmental and cost issues but you can circumvent this by leaving out your tap water overnight to allow the chemicals in it to dissipate before using it to water your houseplant.
Soil Conditions
Peace lilies detest drenched soil and soggy roots. That means only using pots that have drainage holes at the bottom and ensuring the soil is thoroughly drained after each watering session.
Because they don’t like dry soil either, check soil moisture frequently for dryness to avoid the potential for drought stress.
Too Much Direct Sunlight
Peace lilies are none too fond of direct sunlight and will begin to develop darkened tips if exposed to it.
As a result, it is best to place your houseplant close to windows that receive early morning sunlight; it should be kept out of the direct path of the light, but close enough to it.
Low Humidity
Owing to their origins in tropical forest regions, Peace lilies are accustomed to high humidity. As a result, ambient levels should be maintained at 50% or 60%.
Regular misting can help with raising humidity levels or even placing the plant on top of gravel which stands in very shallow water.
Alternatively, you could also place your plant amid other tropical and humidity-loving houseplants, where it would be able to bask in the moisture they release into the air.
Over Fertilizing
As a rule, shade-tolerant species require less fertilizer than other houseplants. Hence, when fertilizing your Peace lily, it is best to err on the side of caution. To avoid overfeeding, the Clemson Cooperative Extension advises using a quarter of the recommended amount if you happen to be using a fertilizer specifically manufactured for houseplants.
If applied in excessive amounts, fertilizer can cause the buildup of salts in the soil. This in turn can make the roots of your peace lily shrivel up, affecting their ability to absorb water and nutrients. Their reduced function can lead to leaves turning black at their margins, yellowing, and even wilting.
When To Fertilize Peace Lily
Peace lilies should be fed fortnightly in the spring and summer and every six weeks in the fall and winter.
Pests
Pests can affect the health of your leaves. Some of them such as arachnids or insects can cause them to darken and turn black. Below some of the most common culprits which are likely to do just that are examined in greater detail.
Common Pests On Peace Lily
Some of the main pests you may have to contend with in this regard are mealybugs and spider mites. 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: Cousins to scale insects, mealybugs are identifiable by their long antennae, oval-shaped bodies, multiple appendages, and pale waxy covering. They hail from the tropics and actually prefer perennials, just like your peace lily.
No part of a plant is out of bounds to this creepy crawly. Not even its roots. What’s more, they are prolific at reproduction: depending on what species subset they belong to, they may either give birth to their young life or simply hatch 600 eggs. Either way, a new generation will spawn on your peace lily every 4 – 12 weeks.
Mealybugs love plant sap. They’re also pretty voracious and can pose a serious problem to crop plants in warmer climates. They love to attack leaves at the point where they join the stem which can cause them to turn yellow and eventually fall off.
In addition to their sap-sucking activities, mealybugs also leave honeydew in their wake which in turn can cause the growth of sooty mold fungi. Although harmless, mold can affect photosynthesis when present in high concentrations.
Spider Mites: Cousins to spiders, they seem like tiny specs in motion at a first glance. They love to live in colonies on leaves’ undersides and produce a distinguishable web matting. They’re known to be fond of vegetables: think tomatoes, melons, and sweetcorn. However, they are by no means averse to settling on your peace lily.
Spider mites are capable of laying 200 eggs and of rushing through their entire lifecycle in just 7 days. These arachnids are also capable of targeting the cells of your peace lily and draining them for sustenance.
The result: yellowing, bronzing, and eventually shedding — which could affect the overall health of your peace lily.
How To Treat A Pest Infestation On Peace Lily
When it comes to getting rid of these arthropods, bug spray may not always be effective; in the case of mealybugs, their waxy coverings may offer them some protection.
Hence, vigilance is highly recommended to prevent these bugs from making it into 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. It’s safe to use too. First, remove all visible traces of the pest then wipe leaves and stems with a weak solution of dish soap and water. Pay particular attention to stem junctions and the underside of leaves which is where most pests choose to take residence.
Once this is done you can spray the Peace Lily with neem oil and use a clean, dry cloth to wipe all affected areas. Repeat this process until the pest infestation has cleared.
Rubbing alcohol is also another excellent remedy. Similar to using neem oil, you’ll need to remove all traces of the infestation and wipe with a watered-down dish soap solution before soaking some cotton in the rubbing alcohol. Then dab at affected areas. Wipe away any excess rubbing alcohol to avoid damaging delicate stems and leaves.
Whatever method you use to treat a pest infection on your Peaace lily, be sure to quarantine it away from other plants to avoid possible cross-contamination.
Black Leaves On Peace Lily After Propagating
The occasional black leaf on a Peace lily after propagating is not uncommon. The main reasons for this are under-zealous watering or over-fertilizing.
Remember to keep the soil of your propagated plant moist and not soggy and avoid fertilizing until your plant has started growing new shoots. 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.
Black Leaves On Peace Lily After Re-Potting
The process of repotting is pretty similar to propagating with the only difference being that the entire peace lily is moved intact into a new home.
To avoid the possibility of leaves turning black, avoid fertilizing and always plant in fresh potting soil.
Pruning A Peace Lily
Peace lily blooms last for about 4 – 8 weeks. Following that period, they darken and wilt. At that point, you will need to prune them close to the base. Doing so will enable your peace lily to be able to sprout new flowers.
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.
Removing Black Leaves From A Peace Lily
Blackened leaves need to be pruned right away. Since there might be a risk of infection, your pruning shears will benefit from a dip in disinfectant after each removal. Once you’re through there’ll be room for new growth to beautify your plant.
Final Thoughts On Peace Lily Leaves Turning Black
If your Peace lily’s leaves are turning black, consider which one of the following could be to blame: drought stress, overwatering, high temperatures, low humidity, over-fertilizing, direct exposure to sunlight, or use of water containing chlorine. Use the symptom checker at the top of this article to help you establish the cause of the issue.
Maintaining the right balance of plant care by providing the environmental factors that Peace Lilies need and also regularly inspecting your plant will enhance its longevity, and quality of life and keep those leaves verdant and shiny for longer.
