Troubleshooting
African marigold problems — and how to fix them
African marigold (Tagetes erecta) 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.
Botrytis on flower heads
The large, densely packed petals hold moisture and are prone to grey mould in wet summers. Deadhead promptly, space plants at least 30 cm apart, and avoid overhead watering.
Spider mites in hot, dry conditions
Fine webbing on leaves and stippled, pale foliage indicate mite infestation. Improve air circulation, mist foliage lightly with water in the evening, or apply insecticidal soap.
Failure to flower in heat
Very high temperatures (above 32°C) can temporarily arrest bud set. Flowering resumes as temperatures moderate in late summer; do not over-fertilise while the plant is in flower hiatus.
Prevent african marigold problems before they start
Most african marigold issues are care-mismatch, not bad luck. Dial in the basics:
Looking for african marigold in general rather than its problems? Read the full african marigold care guide — light, water, soil and feeding.
African marigold problems — FAQ
Why is my african marigold botrytis on flower heads?
The large, densely packed petals hold moisture and are prone to grey mould in wet summers. Deadhead promptly, space plants at least 30 cm apart, and avoid overhead watering.
Why is my african marigold spider mites in hot, dry conditions?
Fine webbing on leaves and stippled, pale foliage indicate mite infestation. Improve air circulation, mist foliage lightly with water in the evening, or apply insecticidal soap.
Why is my african marigold failure to flower in heat?
Very high temperatures (above 32°C) can temporarily arrest bud set. Flowering resumes as temperatures moderate in late summer; do not over-fertilise while the plant is in flower hiatus.