What Causes Brown Spots on Ficus Leaves?

Finding brown spots on the leaves of a ficus tree can be concerning. These marks are a signal that some aspect of the plant’s care or environment needs adjustment. Identifying the specific cause is the first step toward resolving the issue and helping your ficus recover.

Watering and Root Health Issues

The most frequent reason for brown spots on ficus leaves relates to moisture. Overwatering is a primary concern that leads to a condition called root rot. When soil is consistently waterlogged, roots are deprived of oxygen and can be attacked by fungi, preventing them from absorbing nutrients. This causes leaves to develop soft, dark brown spots, and you may also see yellowing leaves on the lower parts of the plant.

To confirm root rot, gently remove the plant from its pot to inspect the root system. Healthy ficus roots are firm and white or light-colored. Roots that are brown, soft, or mushy with a foul odor indicate root rot, a serious condition where decaying roots can no longer sustain the plant.

Underwatering presents a different set of symptoms. If a ficus does not receive enough water, it will develop crispy, brown edges and tips. These dry spots appear at the leaf’s outer margin and feel brittle. The plant may also begin to drop leaves from all over as it tries to conserve water.

Improper Environmental Conditions

Too much direct sunlight can harm ficus leaves. If a ficus is exposed to harsh, direct sun, it can develop “leaf scorch,” which appears as dry, bleached, or brown patches on the parts of the leaf receiving the most intense light. These spots look burnt as a result of tissue damage.

Low humidity is another environmental stressor for ficus trees. Dry indoor air causes moisture in the leaves to evaporate faster than the roots can absorb it. This imbalance results in brown, crispy leaf tips and edges.

Ficus plants are sensitive to sudden temperature changes and drafts. Placing a ficus near a drafty window, an air conditioning vent, or a heating source can cause stress, leading to the browning of leaves. Cold injury can cause brown blotches to appear on older leaves and distort younger ones.

Pest Infestations and Diseases

Common houseplant pests can damage ficus leaves. Spider mites pierce leaf cells to feed, causing small, yellow or brown stippling marks across the leaf surface. Scale insects and mealybugs feed on plant sap, and their activity can lead to yellowing, browning, and a sticky substance called honeydew.

Fungal and bacterial infections can also manifest as brown spots. Fungal leaf spot diseases appear as distinct brown spots that may have a yellow halo surrounding them. These spots are a result of fungal pathogens that thrive in damp conditions, often made worse by overhead watering. Bacterial leaf spot can create dark, water-soaked lesions on the leaves that eventually turn brown or black.

Treating and Preventing Brown Spots

For leaves damaged by pests or disease, it is best to prune them off with clean, sharp shears to stop the problem from spreading. If the spots are cosmetic, such as from past underwatering or sunburn, removing the leaves is optional and will not affect the plant’s health.

To treat root rot, remove the plant from its pot, trim away all dark, mushy roots, and repot it in fresh, well-draining soil. After repotting, water sparingly until the plant begins to recover. To prevent this, always check the top few inches of soil for dryness before watering again.

To prevent environmental stress, place your ficus in a location where it will receive bright, indirect light. Maintain humidity by misting the plant, using a humidifier, or placing it on a pebble tray with water. Shield the plant from cold drafts and extreme temperature changes. Regularly inspecting the leaves for early signs of pests or disease will allow you to address problems before they become widespread.