Troubleshooting
Wallich's Begonia problems — and how to fix them
Wallich's Begonia (Begonia wallichiana) 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.
Root and stem rot
Overwatering or a poorly draining mix causes the rhizome to collapse; always let the topsoil partially dry and ensure the pot has drainage holes.
Botrytis (grey mould)
Poor air circulation combined with high humidity promotes Botrytis cinerea on leaves and stems; remove affected tissue promptly and improve ventilation.
Vine weevil
Larvae attack the rhizome from beneath the soil surface, causing sudden wilting; inspect the root zone in autumn and treat with nematodes (Steinernema kraussei) when soil temperature allows.
Prevent wallich's begonia problems before they start
Most wallich's begonia issues are care-mismatch, not bad luck. Dial in the basics:
Wallich's Begonia problems — FAQ
Why is my wallich's begonia root and stem rot?
Overwatering or a poorly draining mix causes the rhizome to collapse; always let the topsoil partially dry and ensure the pot has drainage holes.
Why is my wallich's begonia botrytis (grey mould)?
Poor air circulation combined with high humidity promotes Botrytis cinerea on leaves and stems; remove affected tissue promptly and improve ventilation.
Why is my wallich's begonia vine weevil?
Larvae attack the rhizome from beneath the soil surface, causing sudden wilting; inspect the root zone in autumn and treat with nematodes (Steinernema kraussei) when soil temperature allows.