Onions: A Global Culinary Staple You Can Grow

Hundreds of onion types exist, varying in size, form, and sweetness/pungency. They're essential in cuisines worldwide.

About This Plant

Onions are a cool-weather crop requiring a long growing season, so they're usually started from sets (small bulbs). However, set variety selection is often limited; for unusual varieties, start indoors from seed. Stronger-flavored onions store longer; mild, sweet types are more perishable.

Site Selection

Choose a site with full sun and well-drained soil. Loosen soil to 12–15 inches and mix in a 2- to 4-inch layer of compost.

Planting Instructions

Select sets ½–¾ inch in diameter for best results. Plant early in spring—onions prefer cool starts and warm maturation. No trenches needed: grasp sets at the pointed end, root end down, and push into prepared soil to the full depth of the bulb. Soil should barely cover the top. Plant tiny sets at least 1 inch deep for good soil contact. Space sets 4–6 inches apart. If starting from seed, sow indoors 2–3 months before last frost or direct-sow as soon as soil can be worked. Transplants can be set 4 inches apart after heavy frost danger passes. In mild winter areas (South/West), grow short-day varieties in fall/winter for spring harvest.

Care

Keep onion bed well-weeded. Water during summer if rainfall is less than 1 inch per week. Contact your extension office for root maggot controls.

Harvesting

Harvest when ¼ of tops have naturally fallen over and bulbs have papery skins. Pull bulbs and dry in a warm, airy, dark place for 1–2 weeks. Once dry, hang storage onions in mesh bags in a cool, dark location.