Troubleshooting
Genovese Basil problems — and how to fix them
Genovese Basil (Ocimum basilicum 'Genovese') 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 (flowering)
Heat, stress or age sends up flower spikes, turning leaves bitter; pinch out flower buds and the top sets of leaves weekly to keep it leafy.
Downy mildew
Yellowing between leaf veins with greyish fuzz underneath, especially in humid, still air; improve airflow, water at the base, and grow resistant strains where available.
Damping off / root rot
Seedlings collapse and mature plants wilt in cold, soggy soil; use free-draining mix, water sparingly in cool weather, and avoid overwatering.
Cold damage
Leaves blacken below about 10°C (50°F); keep indoors or under cover until nights are reliably warm, and bring container plants in before autumn frosts.
Prevent genovese basil problems before they start
Most genovese basil issues are care-mismatch, not bad luck. Dial in the basics:
Looking for genovese basil in general rather than its problems? Read the full genovese basil care guide — light, water, soil and feeding.
Genovese Basil problems — FAQ
Why is my genovese basil bolting (flowering)?
Heat, stress or age sends up flower spikes, turning leaves bitter; pinch out flower buds and the top sets of leaves weekly to keep it leafy.
Why is my genovese basil downy mildew?
Yellowing between leaf veins with greyish fuzz underneath, especially in humid, still air; improve airflow, water at the base, and grow resistant strains where available.
Why is my genovese basil damping off / root rot?
Seedlings collapse and mature plants wilt in cold, soggy soil; use free-draining mix, water sparingly in cool weather, and avoid overwatering.
Why is my genovese basil cold damage?
Leaves blacken below about 10°C (50°F); keep indoors or under cover until nights are reliably warm, and bring container plants in before autumn frosts.