Troubleshooting
French marigold problems — and how to fix them
French marigold (Tagetes patula) 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.
Spider mites
Common in hot, dry spells; look for fine webbing and pale stippling on leaves. Increase humidity around the plant, remove affected growth, and apply insecticidal soap as needed.
Powdery mildew
White, powdery coating on leaves occurs in humid conditions with poor airflow. Improve plant spacing, avoid overhead watering, and apply a sulphur-based fungicide if severe.
Slugs and snails on seedlings
Young transplants are vulnerable to slug damage at night. Use organic slug pellets, copper tape around containers, or set beer traps nearby.
Prevent french marigold problems before they start
Most french marigold issues are care-mismatch, not bad luck. Dial in the basics:
Looking for french marigold in general rather than its problems? Read the full french marigold care guide — light, water, soil and feeding.
French marigold problems — FAQ
Why is my french marigold spider mites?
Common in hot, dry spells; look for fine webbing and pale stippling on leaves. Increase humidity around the plant, remove affected growth, and apply insecticidal soap as needed.
Why is my french marigold powdery mildew?
White, powdery coating on leaves occurs in humid conditions with poor airflow. Improve plant spacing, avoid overhead watering, and apply a sulphur-based fungicide if severe.
Why is my french marigold slugs and snails on seedlings?
Young transplants are vulnerable to slug damage at night. Use organic slug pellets, copper tape around containers, or set beer traps nearby.