Troubleshooting
Mibuna problems — and how to fix them
Mibuna (Brassica rapa var. nipposinica 'Mibuna') 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.
Bolting in heat
Warmth and long days push it to flower fast, turning leaves bitter. Favour spring, autumn, and overwinter sowings; harvest young.
Flea beetles
Pepper young leaves with small holes. Cover seedlings with fine mesh and keep them growing strongly.
Slugs and snails
Dense rosettes shelter slugs that shred lower leaves, especially in wet, cool conditions. Trap and clear hiding spots.
Downy mildew
Yellow patches with grey fuzz appear in damp, crowded plantings. Improve spacing and airflow and avoid overhead watering late in the day.
Prevent mibuna problems before they start
Most mibuna issues are care-mismatch, not bad luck. Dial in the basics:
Looking for mibuna in general rather than its problems? Read the full mibuna care guide — light, water, soil and feeding.
Mibuna problems — FAQ
Why is my mibuna bolting in heat?
Warmth and long days push it to flower fast, turning leaves bitter. Favour spring, autumn, and overwinter sowings; harvest young.
Why is my mibuna flea beetles?
Pepper young leaves with small holes. Cover seedlings with fine mesh and keep them growing strongly.
Why is my mibuna slugs and snails?
Dense rosettes shelter slugs that shred lower leaves, especially in wet, cool conditions. Trap and clear hiding spots.
Why is my mibuna downy mildew?
Yellow patches with grey fuzz appear in damp, crowded plantings. Improve spacing and airflow and avoid overhead watering late in the day.