Why Does My Dragon Tree Have Black Spots?

Fungal infections often manifest as small black or dark brown spots with a yellow halo. These thrive when water remains on the leaves for extended periods or if the plant is kept in a stagnant, high-humidity environment.

Check: Check if the spots are circular or irregular and if they have a slightly water-soaked appearance or yellow border.

Fix: Prune off severely infected leaves and move the plant to a location with better airflow. Ensure you water only at the base of the plant to keep leaves dry.

When soil remains soggy for too long, the root system begins to decay, which can eventually lead to dark, necrotic lesions appearing on the leaves. Dracaena marginata requires a drying-out period between waterings to prevent this suffocating condition.

Check: Gently lift the plant from its pot and check if the roots appear mushy, dark, or emit a foul, swampy odor.

Fix: Trim away all rotten roots, repot the plant in fresh, well-draining soil, and adjust your watering schedule to ensure the top two inches of soil are dry before adding more water.

Bacteria can enter through small wounds or pores in the leaves, often resulting in darker, faster-spreading spots that may look slimy. This is typically introduced via contaminated tools or severe over-misting.

Check: Look for a slimy or weeping texture in the center of the black spots, which is a hallmark of bacterial rather than fungal growth.

Fix: Immediately isolate the plant from others, sanitize your pruning shears with alcohol, and remove affected foliage, being careful not to touch healthy leaves with the contaminated debris.