Onions

TL;DR: Onions are a cuisine staple whose growth depends on day length, so choose short-, intermediate-, or long-day varieties based on your latitude. Plant sets or transplants in early spring, 1" deep and 4-6" apart, in a sunny spot with loose, nitrogen-rich soil. Keep the bed weed-free, water consistently, then taper off once bulbs reach full size. Harvest when tops yellow and flop over, then cure in a dry, shaded, well-ventilated spot for 2-3 weeks for months of storage. They're also rich in quercetin and sulfur compounds that support heart health and cholesterol.

Onions are a fundamental cornerstone of global cuisine, providing a savory aromatic base for an endless variety of dishes. These members of the allium family are unique because their growth is largely dictated by day length; depending on your latitude, you might grow "short-day," "intermediate-day," or "long-day" varieties. Whether you choose the sharp bite of a red onion, the versatile sweetness of a yellow onion, or the crispness of a white one, growing them at home offers a level of flavor and freshness that store-bought bulbs simply cannot match. When it comes to planting, most gardeners find the most success using "sets"—small, immature bulbs—or transplants rather than starting from seed, as onions have a long growing season. Plant them in the early spring as soon as the soil can be worked, as they are quite frost-hardy. Onions love a sunny location with very loose, well-draining soil that is rich in nitrogen. Carefully tuck the sets into the ground about an inch deep and 4 to 6 inches apart. If you prefer to harvest them as green onions or scallions, you can plant them much closer together and pull them while they are still young and slender. Maintaining onions is primarily a game of weed control and consistent hydration. Because onions have shallow, non-invasive roots, they are easily outcompeted by weeds, so keeping the bed clean is essential for bulb development. They require regular watering to grow large and juicy, but it is important to taper off the water once the bulbs have reached full size to allow them to go into their dormant state. You’ll notice the bulbs beginning to push up out of the soil as they grow; this is perfectly normal, and you should avoid mounding more dirt over them, as they need the air and space to expand. The signal for harvest is one of the clearest in the vegetable garden: the long green tops will begin to yellow and eventually flop over on their own. Once about half of the tops have fallen, you can gently pull the bulbs from the earth. To ensure they stay fresh for months, "cure" them by laying them in a dry, shaded spot with good airflow for two to three weeks until the outer skins become papery and the necks are completely dry. Beyond their culinary utility, onions are incredibly healthy; they are rich in quercetin—a powerful antioxidant—and contain sulfur compounds that support heart health and help lower cholesterol.