Onions and their relatives add a savory note to dishes, and gardeners have many from which to choose for green stalks or bulbs. Onions come in short-day and long-day varieties. Short-day onions are sweeter onions; pungent onions store better than other types. According to Ohio State University Extension, temperature and day length trigger the formation of bulbs.
Do not pull green or bulb onions out by their tops. Dig beneath the onions to lift them from the soil. Cut the flower stalks off of any onion plants you are raising for bulbs. The energy the plant puts into flowering will detract from the development of the bulbs.
Things You'll Need
- Garden fork or spade
Gather green onions as you want them for use. Onions are edible during any stage of their development, so precise timing is unnecessary. Green onions reach maturity within 30 days when raised from onion sets. Plant several rows of green onions closely spaced, and you can harvest alternating onions to leave more space for bulb development in the remaining onions.
Harvest bulb onions when their tops dry out and fall over. Cure these onions before storage by allowing the necks and exteriors to dry in a warm, well-ventilated area. The skins will show signs of shrinkage when the onions are ready to store. This process takes two to four weeks. Store onions in a cool place, in a container that allows ventilation. To prevent sprouting, ensure that storage temperatures remain below 40 degrees F.
Pull scallions by hand when they reach the size you desire. Scallions are valued for the length of their white shanks, so they frequently aren't gathered until their shanks reach a 1/4- to 3/4-inch diameter and 2 to 3 inches in length. This typically occurs at 60 to 90 days after direct seeding.
Collect walking onions as you would a green or spring onion. Select the onions while they are tender. Gather the top-sets for use as a small onion. Walking onions, also known as winter onions or Egyptian onions, grow as perennials. Their tops fall over and begin to root once they contact the soil.
Collect shallots as green onions or bulbs. Gather the green onions once they reach 6 to 8 inches in height. The plants take approximately six weeks to reach this stage. Dig for the bulbs when the tops turn yellow.
Harvest leeks at any time after their stems measure 1 inch or larger in diameter for most varieties or 1/2- to 3/4-inch size for smaller varieties. Remove the plants by twisting while pulling, or you can dig them using the same method as for onions.
- University of Minnesota Extension Service; Yard and Garden Brief -- Growing Onions; Beth Jarvis; July 2001
- University of Minnesota Extension; Growing Onions in Minnesota Home Gardens; Cindy Tong; February 2009
- University of Rhode Island Cooperative Extension: Children's Vegetable Garden: Garlic, Egyptian Walking Onions, and Leeks
- University of Nebraska-Lincoln Extension; Historical Materials: Growing Scallions (Green Onions) for Market Gardeners; Laurie Hodges; 2004
- Cornell Cooperative Extension of Oneida County; Home Grown Facts: Growing Shallots; 2006
- University of Minnesota Extension; Leeks; Jill MacKenzie; 2008
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