Troubleshooting
Begonia 'Black Coffee' problems — and how to fix them
Begonia 'Black Coffee' (Begonia 'Black Coffee') is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Rhizome rot
Overwatering or burying the rhizome causes rot. Keep the rhizome on the surface, use a fast-draining mix, and let the soil surface dry between waterings.
Browning leaf edges
Low humidity or salt build-up from over-feeding. Raise humidity and flush the soil occasionally, feeding sparingly.
Powdery mildew
Stagnant humid air promotes mildew. Improve airflow and avoid splashing the leaves.
Pale or stretched growth
Too little light dulls the dark colour and stretches stems. Move to brighter indirect light.
Prevent begonia 'black coffee' problems before they start
Most begonia 'black coffee' issues are care-mismatch, not bad luck. Dial in the basics:
Looking for the species overview? Begonia — the full care guide.
Begonia 'Black Coffee' problems — FAQ
Why is my begonia 'black coffee' rhizome rot?
Overwatering or burying the rhizome causes rot. Keep the rhizome on the surface, use a fast-draining mix, and let the soil surface dry between waterings.
Why is my begonia 'black coffee' browning leaf edges?
Low humidity or salt build-up from over-feeding. Raise humidity and flush the soil occasionally, feeding sparingly.
Why is my begonia 'black coffee' powdery mildew?
Stagnant humid air promotes mildew. Improve airflow and avoid splashing the leaves.
Why is my begonia 'black coffee' pale or stretched growth?
Too little light dulls the dark colour and stretches stems. Move to brighter indirect light.