Onions are used primarily as a flavoring agent, although they are rich in vitamins and minerals and low in calories. Onions are grown from sets, plants, or seed. Sets are small onion bulbs that are planted in the spring to produce green onions—scallions—or bulbs later in the season. Most onion sets for sale in garden centers are usually poorly identified by variety. Plants or transplants are sold in bundles or growing in pots or trays and usually are identified by variety. Choose healthy, fresh plants with good green color. Onions can be grown from seed, but seed produces onions latest in the season, and the small, weak onion plant is difficult to weed or cultivate early in the season.
Onions can be yellow, white, or red. Yellow varieties include Yellow Globe and Early Globe (pungent flavor but good keepers), or improved mild-flavored types such as Fiesta, Texas 1015 Y, Grano, and Granex. Mildest flavored onions are the Bermuda types—Yellow or White Bermuda—while the largest bulbs are produced by Spanish types— Yellow or White Spanish. Benny’s Red and Red Burgundy are popular red varieties.
When to Plant:
Onions grow well in cool or warm weather. They should be planted early so that as much growth as possible occurs before hot, dry weather. Plant sets in mid-March or plants or seed in early April.
Spacing:Onions may be grown in rows as close as 15 inches, with individual plants spaced 2–4 inches in the row, depending on the size of the bulb. Plant sets 1–11⁄2 inches deep, and plant transplants about the same depth.
Care: Onions have a shallow, inefficient root system and need regular watering and fer- tilizing for best results. Onions compete poorly with weeds and other crops. Weed control is essential to reduce competition. Watering may be reduced near the harvest period, but regular timely watering until the tops begin to fall over is needed. Large, vigorous plants are essential for large bulbs with high yields.
Harvest:Onions are ready for harvest when the tops begin to weaken and naturally fall over. This is a signal that the bulbs are as big as they will get. Pull or dig the onions and store in a warm, dry, haded location for 2–4 weeks until the tops and necks are completely dry. After the tops are dry, cut them, trim the roots, and store in a cool dry location. Onions need cool storage, but they should not be stored in a tight plas- tic bag. An open mesh bag is best for storage. Mild-flavored onions keep for only a month or so. Stronger flavored or more pungent onions keep 3–4 months.