Why Are My Pothos Leaves Turning Black?

Discovering black leaves on a pothos is concerning. These resilient houseplants use their leaves to signal distress, and blackening foliage indicates something is amiss. This guide will walk you through the most frequent reasons for black leaves and provide the steps to restore your plant’s health.

The Main Culprit: Overwatering and Root Rot

The most frequent cause of blackening pothos leaves is overwatering. Pothos prefer their soil to dry out between waterings. When soil remains consistently saturated, it cuts off the oxygen supply to the roots. This lack of oxygen causes the root system to decay, a condition known as root rot, which hinders the roots’ ability to absorb water and nutrients.

As root rot progresses, the damage moves upward from the roots. The leaves and stems, starved of sustenance, will turn dark brown or black and become soft and mushy. This discoloration begins at the base of the plant, affecting the leaves closest to the soil first.

To confirm overwatering, assess the soil by touch. If it feels soggy several days after you last watered, it is retaining too much moisture. A sour or musty smell from the soil is another indicator that roots are decaying. For a clear diagnosis, gently slide the plant from its pot to inspect the roots. Healthy roots are firm and white or light tan, while rotted roots are brown or black, mushy, and fall apart easily.

Other Possible Reasons for Black Leaves

If you have ruled out root rot, other environmental factors could be the cause. Fungal or bacterial infections can manifest as black spots on the leaves. Rhizoctonia blight causes irregular, dark spots to form, while bacterial wilt is identifiable by the blackening of the leaf veins. These spots often look different from the uniform blackening seen with root rot.

Sudden exposure to low temperatures is another reason for black leaves. Pothos are tropical plants and are sensitive to cold drafts or frost. If a plant is placed near a drafty window or exposed to temperatures below 50°F, its leaves can rapidly turn black and wilt as the cells are damaged. This damage often appears quickly, sometimes overnight.

Pest infestations can also be a factor. Sap-sucking insects like mealybugs or spider mites stress the plant by feeding on its tissues, which can cause localized spots to die and turn black. Some pests also secrete a sticky substance called honeydew, which leads to the growth of sooty mold. This mold appears as a black, powdery coating on the leaves that can be wiped away.

How to Save Your Pothos

When root rot is the cause, remove the pothos from its pot and gently wash all the soil from the root ball. This allows for a clear view of the root system. Using sterile scissors, trim away every root that is brown, black, or feels soft and mushy. Be thorough, as any infected root left behind can allow the rot to spread again.

After trimming the damaged roots, repot the pothos. Use a new pot or thoroughly sterilize the old one with a bleach solution to kill any lingering pathogens. Fill the clean pot with a fresh, well-draining potting mix. Once repotted, water the plant lightly and place it in a location with bright, indirect light to recover.

If the problem stems from other issues, the solutions are different. For fungal or bacterial leaf spots, trim off the affected leaves with sterile scissors to prevent the disease from spreading. For cold damage, move the plant to a warmer location away from drafts. For pest-related issues, isolate the plant and wipe down each leaf with a damp cloth to remove pests and sooty mold.

Preventative Care for Healthy Leaves

Establishing a proper care routine is the best way to prevent black leaves. This starts with a correct watering technique. Instead of watering on a strict schedule, check the soil moisture first. Insert your finger one to two inches into the soil; if it feels dry, it is time to water. Water thoroughly until it drains from the bottom of the pot, then discard the excess from the saucer.

The choice of pot and soil also prevents overwatering. Always use a container with at least one drainage hole at the bottom. This allows excess water to escape freely. Pairing this with a well-aerating potting mix, such as one with perlite or orchid bark, creates an environment where roots get both moisture and oxygen.

Providing the right environmental conditions supports overall plant health. Pothos do best in bright, indirect sunlight. Sufficient light helps the plant use water more efficiently and allows the soil to dry at an appropriate rate. Good air circulation also helps with soil drying and reduces the likelihood of fungal diseases.