Troubleshooting
Thelma's Begonia problems — and how to fix them
Thelma's Begonia (Begonia thelmae) is generally low-drama, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Rhizome rot in cool, wet conditions
Temperatures below 15 °C combined with wet compost rapidly cause rhizome rot from Pythium; maintain minimum temperatures above 18 °C and ensure the pot drains freely — never allow the base to sit in water.
Botrytis (grey mould) in high-humidity environments
Terrariums and humid cabinets can foster botrytis if airflow is inadequate; introduce a small fan or open the terrarium briefly each day, remove any dying leaf material immediately, and avoid overcrowding plants.
Prevent thelma's begonia problems before they start
Most thelma's begonia issues are care-mismatch, not bad luck. Dial in the basics:
Thelma's Begonia problems — FAQ
Why is my thelma's begonia rhizome rot in cool, wet conditions?
Temperatures below 15 °C combined with wet compost rapidly cause rhizome rot from Pythium; maintain minimum temperatures above 18 °C and ensure the pot drains freely — never allow the base to sit in water.
Why is my thelma's begonia botrytis (grey mould) in high-humidity environments?
Terrariums and humid cabinets can foster botrytis if airflow is inadequate; introduce a small fan or open the terrarium briefly each day, remove any dying leaf material immediately, and avoid overcrowding plants.