Black coating (sooty mold)

Signs to check

• The black coating comes off easily when rubbed with a finger or damp cloth.
• The texture is dry and powdery but may also feel slightly sticky.
• Mainly appears on the upper sides of leaves, where a sticky deposit is often present.
• Unlike a spot, this deposit is superficial and is not part of the leaf tissue.

Common causes

1. Aphids · Small, pear-shaped insects, often clustered on new growth.
2. Mealybugs · White, cottony clusters in leaf axils and on stems.
3. Armored scales · Small, immobile, waxy shells, 1 to 3 mm (about 0.04 to 0.12 in) across, on stems and leaves.
4. Sooty mold · A black, soot-like coating covering leaves.
5. Whiteflies · Clouds of small white insects that fly up when leaves are touched.

What you see on leaves

• White, cottony coating
• Dry, brown leaf edges
• Yellowing lower leaves
• Distorted or twisted leaves
• Brown spots on leaves
• Large black spot
• General leaf yellowing
• Yellow leaves with green veins
• Curling leaves
• Brown leaf tips
• Clean-edged holes in leaves
• Wilting leaves