Direct seed in early spring in rich, well-drained soil as soon as soil can be worked. Sow seed 1.5 cm deep and 1.5 cm apart in rows or bands. For short season gardens, start indoors 8-12 weeks before last frost date. When seedlings reach 12 cm in height cut them back to 3 cm in order to thicken them up. Plant out 10-15 cm apart. Keep evenly moist and weed free especially when seedlings are small. Harvest sweet eating onions any time after bulb formation. For storage onions, allow tops to fall over and field cure for a week or so to dry the skins then harvest.
(For bunching onions: Direct seed in early spring for summer bunching onions or in July or August for fall and early spring onions. Sow seed 1.5 cm deep and 1.5 cm apart in rows or bands. Keep evenly moist and weed free especially when seedlings are small. Use thinnings in salad. Hilling soil around plants will blanch stems resulting in longer white portions. To harvest loosen soil with a fork and pull plant gently from the soil.)