Troubleshooting
Rocket candytuft problems — and how to fix them
Rocket candytuft (Iberis amara) 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.
Poor germination in warm soil
Seeds germinate best below 18°C. Sowing in warm late-spring or summer conditions often results in poor emergence. Time sowings to autumn or very early spring for optimal germination rates.
Clubroot
As a Brassicaceae member, rocket candytuft is susceptible to Plasmodiophora brassicae in infected soils. Rotate with non-brassica crops, improve drainage, and lime soil to pH 7.5+ to reduce spore viability.
Aphids on flower spikes
Mealy cabbage aphid (Brevicoryne brassicae) and peach-potato aphid (Myzus persicae) colonise tender flower stems. Remove by hand or with a strong water jet; introduce aphid predators. Severe infestations may distort developing flowers.
Prevent rocket candytuft problems before they start
Most rocket candytuft issues are care-mismatch, not bad luck. Dial in the basics:
Looking for rocket candytuft in general rather than its problems? Read the full rocket candytuft care guide — light, water, soil and feeding.
Rocket candytuft problems — FAQ
Why is my rocket candytuft poor germination in warm soil?
Seeds germinate best below 18°C. Sowing in warm late-spring or summer conditions often results in poor emergence. Time sowings to autumn or very early spring for optimal germination rates.
Why is my rocket candytuft clubroot?
As a Brassicaceae member, rocket candytuft is susceptible to Plasmodiophora brassicae in infected soils. Rotate with non-brassica crops, improve drainage, and lime soil to pH 7.5+ to reduce spore viability.
Why is my rocket candytuft aphids on flower spikes?
Mealy cabbage aphid (Brevicoryne brassicae) and peach-potato aphid (Myzus persicae) colonise tender flower stems. Remove by hand or with a strong water jet; introduce aphid predators. Severe infestations may distort developing flowers.