How to Care for Onion Plants
Exposure to the air helps the papery skin firm up, preventing rot
Welcome to Homegrown/Homemade, a video series from FineGardening.com. We’ll be following a gardener (Fine Gardening executive editor Danielle Sherry) and a cook (Sarah Breckenridge) as they plant, maintain, harvest, store, and prepare garden vegetables. If you’re new to vegetable gardening, you’ll find these videos very helpful. In this video, the topic is onions.
Episode 2: How to Care for Onion Plants
As the onions grow, the bulbs enlarge, and when that happens, it’s time to “unearth.” You simply move the soil away from the tops of the bulbs. Exposure to the air helps the papery skin firm up, preventing rot. Leave only the lowest part of the bulb in contact with the earth.
Onions have a reputation for being hard to grow, so here are some tips to help. Onions can be started from seed or from sets (tiny bulbets). With seeds you have more choice of varieties, and you can choose varieties that are suited to your region. (In the North, plant long-season onions in the spring; in the South, short season onions, planted in the fall, are best.)
Start your seeds, transplant into larger cells, and before planting out, harden them off by putting the pots outside for several days. In the garden, onion plants should be spaced 4 to 6 inches apart in the row, with rows 1 to 2 feet apart. Plant each one about 1/2 inch deep in a small hole. After planting, trim the tops to about 4 inches.
Onions need about 1 inch of water per week, so if the weather is dry, you’ll need to water.
Onions need a long growing season. Plan on harvesting toward the end of summer. It’s easy enough to harvest them by pulling them out of the ground. The most important thing is to cure the bulbs, which means allowing them to air-dry for about a month with their tops on. Spread the bulbs evenly on trays or screens and allow them to air-dry in a cool, dry spot. Then cut off the tops (leaving an inch or so behind), brush off any dirt, and store until you’re ready to use them.