Your peace lily leaves turning black could be due to your houseplant care skills.
This isn’t a problem you can ignore and hope it would just go away because peace lilies are supposed to be low-maintenance and easy-to-care-for plants.
While it is true that the perennial and largely evergreen, herbaceous plants are popular as houseplants requiring minimal care to thrive, excessive neglect can lead to a myriad of issues.
The black leaves are usually a symptom of a bigger problem.
In this article, we would explore the causes of black peace lily leaves and all the possible solutions.
Most importantly, we would also discuss the ways you can prevent this and many other problems with some simple, peace lily care tips.
Peace Lily Leaves Turning Black
Peace lilies (Spathiphyllum) are tropical plants native to the rainforest of Asia and South America.
That means they naturally thrive in areas with lots of rainfall and high relative humidity.
The soil in these areas is packed with organic nutrients from decaying organic matter.
These are the basic growth conditions that many houseplant lovers have replicated to successfully grow peace lilies.
Peace lily leaves turning black is the consequence of a serious deviation from the growing conditions, especially water and humidity.
These two are the main factors responsible for the problem.
That said, the black leaves could also be the inevitable progression of other problems whose symptoms start out as brown or yellow leaves.
In this case, the black leaves become the final symptom that began as brownish or yellowish discoloration.
As earlier stated, when peace lily leaves turn black, it is usually a pointer that the plant was neglected for too long; most often an indictment of your plant’s parenting skills.
That is the bad news though and it is fairly common among newbie gardeners with busy schedules.
The good news is that the underlying causative factors are quite often easy to fix.
Main Reasons Your Peace Lily Leaves Are Turning Black
Underwatering is generally cited as the most common factor responsible for peace lily leaves turning black.
This is a throwback to the tropical rainforest origin of the plant where there is abundant water and the soil is constantly moist or hardly ever remains dry for too long.
With insufficient soil moisture, the roots are unable to transport the required amount of water and nutrients to the leaves.
The first sign of under-watering is shriveled leaves and discoloration as the leaves become dry and easily susceptible to discoloration.
The leaves, starting from the edges, begin to turn black.
Watering issues might also include over-watering.
However, instead of black, the leaves are likely to turn yellow with too much watering or when the soil retains water for too long.
But with overwatering, a bigger issue to be concerned about is root rot. More on this later.
Solution – When grown in high-quality potting soil that drains well, the ideal watering schedule is about once a week or when the top 1 -2 inches of the soil is dry.
External conditions such as temperature, wind, and humidity can affect how much and how often to water the peace lily though.
So, in the middle of summer when midday temperatures are high, you might water more.
But you need to be careful not to over-water in the rush to solve the problem.
Simply water as usual and until excess water starts draining out of the holes at the bottom.
And always wait until at least the top 2 inches of the soil is dry to begin watering.
As well as inadequate watering, low humidity ranks as a very important reason your peace lily leaves are turning black.
Again, this goes back to the origins of the plants where the humidity is consistently high.
When a peace lily is placed in a dry environment, transpiration through the leaves becomes higher.
The leaves then wilt or shrink, and like in the case of underwatering.
Become susceptible to discoloration (black or brownish) starting from the tips or edges.
Solution – If there is nothing wrong with the watering, you want to check the humidity around the plant.
A humidity of less than 50% implies ‘low’. You can go ahead and take any of the measures below:
- Set the pot on pebbles in a tray or saucer filled with water. With time, evaporating water would raise the humidity around the peace lily.
- If possible, move the potted peace lily to a brightly lit bathroom.
The bathroom, due to the high level of moisture in the air, ranks higher in terms of humidity than most parts of the home.
- If you have other plants, group your peace lily with the other plants to increase the relative humidity
- An easy and inexpensive solution is to install a humidifier if the plant is grown indoors.
- Another easy solution is to mist the leaves with water using a spray bottle.
This method carries a bit of risk as water droplets on the leaves can lead to the proliferation of disease-causing peace lily fungi on the leaves.
So the idea is to mist as little as possible so the leaves can dry out quickly.
Secondary Reasons Peace Lily Leaves Turn Black
If your peace lily leaves are turning black and you don’t have watering or humidity issues, extend your diagnosis to any of the following:
Fertilization – There are several ways the improper application of fertilizer causes black leaves on peace lily.
For instance, adding too much nitrogen-based fertilizer to the soil can alter the pH of the soil to a more acidic environment.
This can burn the roots and ultimately affect the transport of water and nutrients to the leaves.
Also, over-fertilization, or fertilizing when the soil is dry, leaves excess salts in the soil.
The salts invariably absorb soil moisture leaving very little for the plant to use.
Some simple but effective fixes include:
- Stop fertilizing the peace lily for some time
- Drench the soil with excess water to flush out the harmful salts from the soil.
Pests – look for signs of attacks by some common peace lily peats such as mealybugs, scales, and mites.
They suck on leave sap rendering them unhealthy.
This in turn prompts the discoloration of the leaves to brown or black.
You can get rid of these pests by spraying the leaves with pesticides.
Spraying the leaves with neem oil, soap solution, or diluted alcohol are also effective treatments.
Water quality – If the water for irrigating the peace lily contains high levels of fluorides or chlorides, it can also lead to black leaves among other problems.
The easy solution is to stop using tap water and switch to distilled or spring water.
First, though, consider flushing out the offending fluorides or chlorides by drenching the soil with excess water about 3 times.
Root rot – Root rot is a very serious problem with many symptoms including leave discoloration, leaves turning black, wilting plants, etc.
The problem is caused by fungal infestation that thrives in waterlogged or soggy soils ultimately destroying the roots.
You can easily diagnose the problem by uprooting the plant. The black roots with a bad odor are all the evidence you need.
This problem has no solution, your best bet is to prevent it. You want to discard the peace lily and potting soil immediately.
The following are all the easy peace lily care and maintenance tips you need to prevent peace lily root rot:
- Use only well-draining, high-quality potting soil to plant or propagate peace lily
- Never overwater the soil.
- Water only when the soil is dry
- Make sure the drainage holes at the bottom are never blocked
Peace lily, like most popular houseplants, is used to improve the décor of any living space.
What makes them even more desirable is that they are very easy to grow with few requirements in terms of care and maintenance.
However, with extreme neglect, peace lily leaves can turn black as an SOS call to action before it is too late.
The main causes of the peace lily black leaf problem are underwatering and low humidity – two issues that are quite easy to fix.
Other factors, also linked to inadequate or improper care practices, can lead to the problem too.
Again, most often than not, fixing the problem caused by these secondary factors isn’t hard.