Long-day varieties for latitudes above 36°N; short-day for southern regions. Start from transplants or sets for earlier bulbing. Bulbing is triggered by day length — choose correct type for your latitude. Stop watering when tops fall over. Cure 2–4 weeks in warm, dry, well-ventilated place before storage.

Want Tomatograph to track onion for you — frost alerts, weekly reviews, and care logging included? Browse the full library or get started free.