Troubleshooting
Corn Marigold problems — and how to fix them
Corn Marigold (Glebionis segetum) 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.
Aphid infestations
Blackfly and greenfly colonise soft stem tips, especially in warm, sheltered conditions; blast off with water or apply insecticidal soap early before populations build.
Grey mould (Botrytis cinerea)
Prolonged wet weather causes fluffy grey mould on stems and flowers; thin plants for air circulation, remove dead flower heads promptly, and avoid overhead watering.
Prevent corn marigold problems before they start
Most corn marigold issues are care-mismatch, not bad luck. Dial in the basics:
Corn Marigold problems — FAQ
Why is my corn marigold aphid infestations?
Blackfly and greenfly colonise soft stem tips, especially in warm, sheltered conditions; blast off with water or apply insecticidal soap early before populations build.
Why is my corn marigold grey mould (botrytis cinerea)?
Prolonged wet weather causes fluffy grey mould on stems and flowers; thin plants for air circulation, remove dead flower heads promptly, and avoid overhead watering.