Onions

Planting onions

Set out plants or transplants in early spring as soon as the soil can be worked. Match the variety to your latitude: short-day types for the south, long-day types for the north.

Planting details

• Sets are easiest; plants and seed grow larger bulbs
• Spacing: 4 to 6 inches in rows
• Keep beds weed-free; onions compete poorly

Growing requirements

Onions need full sun, fertile loose soil, and steady moisture early. Bulbs form in response to day length, which is why variety choice matters more than fertilizer.

Harvesting and care

Water until tops start to fall, then stop. Cure bulbs in a dry, airy spot for 2 weeks once tops have browned before storing.

Common mistakes

• Planting a long-day variety in the south, or short-day in the north, which gives tiny bulbs
• Letting weeds overrun the bed, since onions have shallow roots and poor competition
• Harvesting before tops fall, which produces bulbs that store badly

Companion plants

Onions fit beside carrots, beets, and lettuce. Keep them away from peas and beans, which they can stunt.