The Peace Lily Plant, also known as a Spathiphyllum, is a well-loved indoor plant known for its striking deep green foliage and elegant, hooded white flowers. So, it can be quite disconcerting to find this beautiful houseplant sporting blackened leaves.
If you see your peace lily leaves turning black, fear not! This is usually an indication of a care and maintenance problem.
Let’s look at the most common reasons why the peace lily leaves are turning black. Identify the underlying cause and find a solution to revive your peace lily.
Causes of Peace Lily Leaves Turning Black
1. Water Quality Issues
Poor water quality is one of the primary reasons for foliage blackening. This can be at the root of your plant’s leaves turning black.
Most people water their houseplants with common city tap water. Tap water contains numerous impurities and chemicals. Two of the most prevalent are fluoride and chloride.
When these chemicals enter the soil bed, they will negatively affect the plant’s absorption of essential nutrients present. Your plant will begin to absorb fluoride and chloride, which are toxic, and doesn’t provide any soil nutrients.
The presence of chemicals and lack of nutrients will affect the color of foliage. The green leaves may turn yellow, brown, and/or develop black spotting.
Water Quality Solution
Use filtered water, distilled water, or collected rainwater to water your plants.
If you want to use tap water, leave the water out overnight for the chlorine, fluoride, and other impurities to evaporate or sink to the bottom of the container.
2. Improper Watering Issues
Peace lilies call tropical rain forests their native habitat. Therefore, they receive sufficient water thanks to the frequent rain in these locations.
That means your peace lily will require a bit more water than other houseplants that you may own. If you underwater your peace lily, its leaves may blacken.
But also be careful with high watering frequency. Overwatering can also contribute to the development of black leaves because your plant is left standing in water.
Improper Watering Solution
Water your plant once or twice a week depending on the season and how quickly the soil dries. As a rule of thumb, do not water your plant until the top two inches of the soil bed are completely dry.
If you do see any black leaves, be sure to remove any black, decayed leaves.
3. Over Fertilization Issues
Who would imagine that a plant can be fed too much! However, if a peace lily is over-fertilized, an excess of salt may build up in the soil bed.
Salt build-up clogs up the soil, impeding the root system from absorbing adequate water. If the roots do not absorb water, they will not be able to absorb nutrients either.
With the lack of absorption of specific nutrients such as magnesium, potassium, iron, and copper, the foliage will die because of necrosis. This is a primary reason for peace lily leaves to begin turning black, starting with the leaf tips.
Over Fertilization Solution
After removing any black leaves, place your plant in a sink to start removing excess fertilizer, excess salts and mineral deposits.
Turn on the tap and allow the water to run through the soil bed for several seconds. Allow the water to drain out and take out the high amounts of fertilizer left over. Then repeat the entire process three to four times.
Once the plant has drained thoroughly, it can be returned to its usual spot.
4. Cold Temperatures
As a tropical plant, the peace lily is not a cold-hardy houseplant. It will not survive in the cold. If the temperature drops below 25°C, the plant will suffer damage.
In colder environments, these plants are at risk of cold injuries because the lower temperatures disturb the plant’s metabolism. Consequently, the roots will not absorb water and the leaves will turn black.
Cold Temperature Solution
If cold temperatures are responsible for leaves blackening, do not trim leaves for the moment. Your plant is in shock. It will require several days to recover from the shock.
First, place your peace lily in a warmer location. Greenhouses are an ideal environment in these situations. When temperatures return to normal springtime levels, you can prune the damaged leaves.
5. Fungal Infection and Root Rot
If the soil bed of your peace lily is constantly overly moist, it becomes the perfect breeding ground for fungal infections and root rot.
The first symptom of a fungal infection or root rot will be the appearance of black spots on leaves and the entire leaf may follow.
Remove spotted leaves immediately to prevent the spread of the fungus. Your plant may also be suffering from root rot due to being left standing in excess water or waterlogged soil.
Fungal Infection and Root Rot Solutions
The problem with fungal infections is that they are not limited to where the spots appear, they may already have infected healthy-looking parts of your plant. Because of this, applying a fungicide is recommended to stop fungal growth.
Baking soda works well against fungal infections and is a gentler solution than chemical products. It’s a great homemade antifungal agent solution.
Put one tablespoon of baking soda in a spray bottle with one liter of water. Shake and agitate the mixture well, and then spray the leaves of your plant.
In the case of root rot, you need to remove the plant from the soil bed. Trim away any affected roots. Rinse the healthy roots and allow them to dry. Repot your plant in fresh potting soil. Wait a couple of days before resuming watering.
6. Low Humidity Conditions
Again, because it is a tropical rainforest plant, the peace lily loves high humidity levels. For your plant to thrive and be healthy, its natural environment needs to be mimicked.
If you place your plant in a dry location with low humidity, its foliage will suffer. They will begin by wilting and then turn black.
When trying to identify the cause of your plant’s leaves turning black, check the level of humidity in the room where you have positioned them.
If the humidity measures below 50%, the black leaves are a result of low humidity.
Low Humidity Solution
A humidifier is the easiest solution for plants that require elevated humidity levels. Other options include misting your plant several times a week or grouping several plants together to raise the humidity level in the area.
Another simple solution is to create a pebble tray and place your plant pot on top of it. This will raise the humidity around the plant.
Take a tray and fill it with pretty pebbles, stones, or rocks. Proceed to fill the tray with water, then set your peace lily on top of it. The drainage holes in your plant’s container should not come into contact with the water in the tray.
General Tips to Prevent Peace Lily Leaves Turning Black
Now that you know what can cause peace lily leaves to turn black, let’s take a look at how to prevent the leaf color from changing.
General tips for keeping your peace lily healthy and preventing leaves from turning black include:
- Position your plant in bright indirect sunlight, although it will also adapt to low and medium-light environments. Just keep the peace lily out of direct sunlight, like the majority of common houseplants.
- Fertilize monthly during the growing season with half-strength liquid fertilizer. Do not fertilize the remainder of the year during its dormancy period.
- Water weekly and perhaps biweekly during warmer weather.
- Keep your peace lily in a warm environment with a humidity level above 50%.
- Examine your plant regularly for signs of pest infestations or infections and treat immediately.
- Remove yellow, brown and black leaves from the peace lily, because they will not return to being green.
Peace Lily Leaves Turning Black Final Thoughts
If you want to keep your peace lily looking beautiful, make sure you provide it with the right environmental conditions. If you do not, you may find yourself having to replace your peace lily every few months.
The peace lily is an elegant plant that will bring beauty to any décor. With attentive care and maintenance, you can prevent your plant from developing black leaves.
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