Sunlight: Full sun (6+ hours daily).
Soil: Loose, well-drained soil, rich in organic matter.
Watering: Keep soil consistently moist (especially while bulbs are forming), but not waterlogged.
Other tips:
Keep weeds down to prevent competition.
Bulb onions are annuals in Minnesota.
Transplanting: Plant so that the bulb sits just below the soil surface.
Fertilization: Use nitrogen-rich fertilizer (21-0-0) every 2-3 weeks early, then reduce nitrogen once bulbs form.
Bunching onions are perennials in Minnesota.
Transplanting: Plant at the same depth as in the pot.
Harvest frequently, when stems are pencil-thin.
Fertilization: Use nitrogen-rich fertilizer (21-0-0) monthly during active growth.