Troubleshooting
Spreading Begonia problems — and how to fix them
Spreading Begonia (Begonia extensa) 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.
Stem blight along spreading stems
Stems lying on wet or poorly ventilated compost are prone to Botrytis or Pythium stem blight, appearing as dark, water-soaked lesions; lift stems clear of the compost surface and improve air circulation.
Aphid infestations on new growth
Soft new shoot tips attract aphid colonies that distort emerging leaves and deposit honeydew; blast off with a strong water jet, then follow up with insecticidal soap or a systemic neem oil drench.
Prevent spreading begonia problems before they start
Most spreading begonia issues are care-mismatch, not bad luck. Dial in the basics:
Spreading Begonia problems — FAQ
Why is my spreading begonia stem blight along spreading stems?
Stems lying on wet or poorly ventilated compost are prone to Botrytis or Pythium stem blight, appearing as dark, water-soaked lesions; lift stems clear of the compost surface and improve air circulation.
Why is my spreading begonia aphid infestations on new growth?
Soft new shoot tips attract aphid colonies that distort emerging leaves and deposit honeydew; blast off with a strong water jet, then follow up with insecticidal soap or a systemic neem oil drench.