Allium cernuum · Bulb
Allium leaf miner: Remove affected foliage immediately after flowering to break the life cycle.
Onion white rot: Avoid planting alliums in infected soil for at least 10 years; ensure good drainage.
Onion fly: Use insect-proof netting from early spring to protect emerging foliage.
Onion downy mildew: Improve air circulation and avoid overhead watering to keep foliage dry.
Slugs and snails: Apply slug pellets or use beer traps around the base of plants.