Troubleshooting
Seville orange problems — and how to fix them
Seville orange (Citrus aurantium) 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.
Sooty mould on leaves
Black fungal coating follows scale or aphid honeydew. Treat the underlying pest first with horticultural oil, then wipe sooty mould off leaves with a damp cloth.
Thorns on grafted suckers
Vigorous thorny shoots from below the graft union are rootstock suckers. Remove them immediately at the point of origin — they will outcompete the scion if left.
Cold-induced leaf drop
Brief temperatures below 0°C or prolonged cold above 5°C cause leaf drop. Move containerised specimens to a frost-free glasshouse or cool conservatory in winter.
Prevent seville orange problems before they start
Most seville orange issues are care-mismatch, not bad luck. Dial in the basics:
Looking for seville orange in general rather than its problems? Read the full seville orange care guide — light, water, soil and feeding.
Seville orange problems — FAQ
Why is my seville orange sooty mould on leaves?
Black fungal coating follows scale or aphid honeydew. Treat the underlying pest first with horticultural oil, then wipe sooty mould off leaves with a damp cloth.
Why is my seville orange thorns on grafted suckers?
Vigorous thorny shoots from below the graft union are rootstock suckers. Remove them immediately at the point of origin — they will outcompete the scion if left.
Why is my seville orange cold-induced leaf drop?
Brief temperatures below 0°C or prolonged cold above 5°C cause leaf drop. Move containerised specimens to a frost-free glasshouse or cool conservatory in winter.