Common plant pests & diseases.

Black surface mould thriving on damp foliage.

Mushy black roots from waterlogged soil, silent killer.

Soft-bodied sap-suckers on new growth, sticky honeydew, curled tips.

Cottony white clusters in leaf joints; weaken plants by feeding on sap.

Tiny arachnids → yellow speckling + fine webbing under leaves.

Brown bumps on stems and leaf veins; sticky residue.

Clouds of small white flies; yellow leaves and honeydew.

Slender flying insects; silvery streaks + deformed new growth.

Tiny dark flies from over-wet soil, larvae damage roots.

Brown/black circular spots from bacterial or fungal infection.

White powdery coating on leaves in humid still air.

Orange-rust pustules under leaves; spreads fast in damp weather.

Fuzzy grey mould on dying tissue; thrives in humid cool air.

Water-soaked dark patches that yellow then necrotize.

Black soot-like coating from honeydew left by aphids/scale.

Yellow upper-leaf patches + grey under-leaf fuzz.

Sunken brown lesions on leaves and stems.

Microscopic worms attacking roots, wilting despite watered soil.

5 likely causes ranked by frequency, ranked diagnosis.