What Causes Black Spots on a Fiddle Leaf Fig?

Discovering black spots on a fiddle leaf fig can be alarming. These spots are a common issue, and understanding the underlying cause is the first step toward a solution. This guide will help diagnose the reason for the black spots and provide clear steps to resolve the problem.

Root Rot From Overwatering

The most frequent cause of black spots on a fiddle leaf fig is root rot, a fungal issue from overly moist soil. These spots manifest as dark brown or black areas, typically starting on the lower leaves. The discoloration may appear in the center of the leaf or near the main stem and will feel soft and mushy, not dry or crispy.

To confirm root rot, inspect the plant’s root system. Gently slide the plant out of its container to get a clear view. Healthy roots appear off-white or light tan and feel firm, while roots suffering from rot will be brown or black, feel mushy, and may have an unpleasant odor.

Once root rot is confirmed, use clean, sterilized scissors to prune away all affected roots. After pruning, dispose of the old soil and repot the plant into a new container that has excellent drainage, using a fresh, well-draining potting mix.

Bacterial Leaf Spot Infections

Black spots can also be the result of a bacterial infection, which presents differently than root rot. Bacterial spots are small and dark and can appear on any leaf. A distinguishing feature is the presence of a distinct yellow halo surrounding each black spot. These spots can multiply and eventually merge into larger patches.

This infection develops in environments with high humidity and poor air circulation. Water sitting on the leaves for extended periods can create the ideal conditions for bacteria to thrive. Unlike root rot, which starts below the soil, bacterial leaf spot begins on the foliage.

To treat a bacterial infection, remove all affected leaves with clean pruning shears to prevent the bacteria from spreading. Subsequently, adjust your watering habits to avoid wetting the leaves and improve air movement around the plant.

Other Potential Causes of Black Spots

Pest infestations can lead to tiny, stippled black or brown dots on the leaves. Spider mites, for instance, are a common pest that feeds on the leaf’s cellular contents, causing this pattern. To confirm their presence, inspect the undersides of the leaves for fine, silk-like webbing and treat with an insecticidal soap.

Direct sun exposure can also be a source of black or brown spots, commonly referred to as sunburn. These spots will look dry and crispy and may appear bleached. Sunburn primarily affects the top leaves that receive the most intense, direct sunlight. The solution is to move the plant to a location where it will receive bright, but indirect, light.

Physical damage is another cause of black spots on fiddle leaf fig leaves. Bumps or scrapes that occur during handling can bruise the leaf tissue, resulting in dark marks. These spots are purely cosmetic, will not spread, and require no treatment.

Preventative Care for Healthy Leaves

Consistent and proper watering is fundamental to preventing problems. Water the plant thoroughly only when the top 2-3 inches of soil feel dry. When you do water, continue until water flows freely from the drainage holes, and then empty any excess water from the saucer. This practice helps prevent the overwatering that leads to root rot.

Providing the right environment is also important for leaf health. These plants thrive in bright, indirect sunlight, which prevents leaf scorch. Good air circulation helps keep the leaves dry and discourages the development of bacterial or fungal diseases.

Regular leaf maintenance contributes to the overall health of your plant. Gently wipe the leaves with a soft, damp cloth to remove dust. This enhances its ability to photosynthesize and allows you to spot pest problems early. Avoid misting the leaves, as this can increase the risk of bacterial spots.