Troubleshooting
Begonia 'Merry Christmas' problems — and how to fix them
Begonia 'Merry Christmas' (Begonia rex-cultorum 'Merry Christmas') 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.
Powdery mildew
White dusty patches on leaves from stagnant, humid air. Improve airflow, avoid wetting foliage and remove affected leaves promptly.
Botrytis (grey mould)
Fuzzy grey rot on stems and leaves in cool, damp, still conditions. Cut out affected tissue and water at the base, not overhead.
Crispy brown leaf edges
A sign of low humidity or underwatering. Raise humidity with a pebble tray and keep the mix evenly moist.
Rhizome rot
Mushy, blackened rhizome from overwatering or heavy soil. Use a free-draining mix, a shallow pot and let the surface dry between waterings.
Prevent begonia 'merry christmas' problems before they start
Most begonia 'merry christmas' issues are care-mismatch, not bad luck. Dial in the basics:
- Common rex begonia problems — the species this cultivar belongs to
- What's wrong with my plant? — the diagnosis apps compared
- Begonia 'Merry Christmas' watering schedule
- Begonia 'Merry Christmas' light requirements
- Best soil mix for begonia 'merry christmas'
- Begonia 'Merry Christmas' temperature & humidity
- Full begonia 'merry christmas' care guide
Looking for the species overview? Begonia — the full care guide.
Begonia 'Merry Christmas' problems — FAQ
Why is my begonia 'merry christmas' powdery mildew?
White dusty patches on leaves from stagnant, humid air. Improve airflow, avoid wetting foliage and remove affected leaves promptly.
Why is my begonia 'merry christmas' botrytis (grey mould)?
Fuzzy grey rot on stems and leaves in cool, damp, still conditions. Cut out affected tissue and water at the base, not overhead.
Why is my begonia 'merry christmas' crispy brown leaf edges?
A sign of low humidity or underwatering. Raise humidity with a pebble tray and keep the mix evenly moist.
Why is my begonia 'merry christmas' rhizome rot?
Mushy, blackened rhizome from overwatering or heavy soil. Use a free-draining mix, a shallow pot and let the surface dry between waterings.