Onion
The humble onion is one of the oldest cultivated vegetables on Earth, bringing depth and sweetness to cuisines across every culture.
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Layers of History
Onions have been cultivated for at least 5,000 years, prized by ancient Egyptians, Romans, and medieval Europeans alike. They belong to the allium family alongside garlic, leeks, and chives, and share that signature sulfur chemistry responsible for both their bite and their health benefits.
Varieties range from mild, sweet Vidalias and Walla Wallas to sharp storage types like Yellow Globe and Red Zeppelin. Day-length sensitivity divides them into short-day types best for southern gardens and long-day types suited to northern latitudes, so choosing the right variety for your region is essential.
Planting & care
Start onions from seed indoors 10-12 weeks before your last frost, or plant sets and transplants directly in the ground as soon as soil can be worked in early spring. Choose a well-drained bed with loose, fertile soil and a pH of 6.0-7.0. Space plants 4-6 inches apart in rows 12 inches apart, and work in a balanced fertilizer or compost before planting.
Once established, onions need consistent moisture and regular feeding with a nitrogen-rich fertilizer through midsummer to build large bulbs. Stop fertilizing once the necks begin to soften and bulbs start to push up out of the soil. Pull and cure onions in a warm, dry, airy spot for 2-4 weeks before storing in a cool, dark location.
Read the Neck, Not the Calendar
Onions tell you when they are ready - when about half the tops have fallen over naturally, bend the rest down yourself and wait a few more days before harvesting. Curing is not optional: skipping it leads to rot in storage. A properly cured, thick-necked storage onion can last 6 months or more in the right conditions.
How much sun does Onion need?
Onion grows best in full sun.
How often should you water Onion?
Give it about 1 in per week.
When is Onion ready to harvest?
Onion is usually ready in 100-120 days from seed, 60-80 days from transplant or sets.