Troubleshooting
Empress of India Nasturtium problems — and how to fix them
Empress of India Nasturtium (Tropaeolum majus) 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.
Aphids (blackfly and greenfly)
A classic aphid host; knock off with a water jet or apply insecticidal soap promptly to avoid heavy infestations.
Large White caterpillars
Can strip foliage; hand-pick eggs and larvae or apply Bt spray.
Powdery mildew
Late-season issue in humid weather; remove affected foliage and improve spacing.
All foliage, few flowers
Almost always caused by rich soil or over-fertilising; transplant to a leaner bed.
Slugs and snails
Damage young seedlings; protect with physical barriers or iron phosphate-based slug control.
Prevent empress of india nasturtium problems before they start
Most empress of india nasturtium issues are care-mismatch, not bad luck. Dial in the basics:
Empress of India Nasturtium problems — FAQ
Why is my empress of india nasturtium aphids (blackfly and greenfly)?
A classic aphid host; knock off with a water jet or apply insecticidal soap promptly to avoid heavy infestations.
Why is my empress of india nasturtium large white caterpillars?
Can strip foliage; hand-pick eggs and larvae or apply Bt spray.
Why is my empress of india nasturtium powdery mildew?
Late-season issue in humid weather; remove affected foliage and improve spacing.
Why is my empress of india nasturtium all foliage, few flowers?
Almost always caused by rich soil or over-fertilising; transplant to a leaner bed.
Why is my empress of india nasturtium slugs and snails?
Damage young seedlings; protect with physical barriers or iron phosphate-based slug control.