Onions

onion plants

Onions are cool season plants that need to be planted at specific times to have good growth. Bulbing and green onions are biennial plants that are grown as annuals in the cool, spring growing season. Other types of onions, including Egyptian walking onions, multiplier onions, and shallots are hardy perennials that are either planted as perennials (walking onions) or are planted in the fall for harvest the following summer (multiplier onions and shallots). Onions can be yellow, white, or red and vary in sweetness and pungency. Some varieties are better for long storage than others.

The most important consideration when selecting onion varieties is knowing the latitude of your location. Onion varieties are categorized into “long day,” “intermediate,” and “short day” varieties. Long day varieties develop bulbs when there are 15 to 16 hours of sunlight and are adapted for more northerly areas (latitudes 37 to 47). Intermediate day varieties perform best in latitudes 32 to 42. Short day varieties perform best in latitudes 25 to 35. This means that intermediate day varieties are best for all of Kansas, while some long day varieties may do well in the northern parts of the state. Gardeners along the southern edge of Kansas could try short day varieties as an experiment, but they likely will not produce large onions in most years. Para información en español, visite este sitio web.

How to Grow

Onion plants or sets need to be planted in mid- to late March so that the majority of growth occurs before the onset of hot, dry weather. If starting from seed, they should be started indoors about 10 to 12 weeks before the expected transplant date, with a goal of having plants that are between a pencil lead and pencil width in diameter before planting.

Onions may be grown in rows as close as 15 inches, with individual plants spaced 2 to 4 inches in the row, depending on the expected size of the bulb. Plant sets 1 to 1½ inches deep, and plant transplants about the same depth. If starting onions from seed start in January to plant in March. Sow seeds 3/4" of an inch deep and keep the soil evenly moist. When you are ready to transplant the plants, gently loosen the soil around the transplant and pull them out of the soil. Trim the roots to 1/2" long and the tops to 4" tall. Plant the plants as described above.

Sunlight: Full sunlight is needed for the best growth.
Watering: Onions have a shallow, inefficient root system and need regular watering to perform well. Provide an inch to an inch and a half of water every week if not provided by rainfall.
Soil and Fertilization: Onions require a good supply of available nitrogen, but too much nitrogen can result in late maturity, large necks that are difficult to cure, soft bulbs, green flesh and poor storage quality. Side dress with fertilizer after root systems are well-developed. Do this once or twice during the growing season, with urea (45-0-0) at a rate of 0.25 to 0.5 pound per 25 feet of row. Spread the fertilizer alongside the row of onions, about six inches away from the plants, and scratch it into the soil.
Pests and Diseases: Onions compete poorly with weeds and other crops. Weed control is essential to reduce competition. Sometimes the bulbs may not develop much size due to lack of fertilizer or water. If the tops are blown over by wind the plant will stop growing.

Harvest and Storage

onion bulbs 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, shaded location for 2 to 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 plastic 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 to 4 months.

Onions can be preserved to provide a longer period of time to use the. For information on preserving onions check out the Center for Home Food Preservation.

Recipes

Onions are a very common addition to many dishes.

Do you cry when you cut onions? When you cut into an onion, the cell walls are damaged releasing a sulfur compound called propanethial-S-oxide which floats into the air. This compound is converted to sulfuric acid when it comes in contact with water which is why it produces the stinging sensation and subsequent tears.

To reduce tearing when cutting an onion, the National Onion Association recommends you "first chill the onions for 30 minutes. Then, cut off the top and peel the outer layers leaving the root end intact." It's the root end that has the highest concentration of the sulphuric compounds that cause your eyes to tear.

French Onion Soup

Ingredients

Directions

l pound yellow onions, sliced ¼-inch into half circles
2 Tbs unsalted butter
½ Tbs all-purpose flour
¼ cup apple cider.
3 cups beef stock
Pinch dried thyme
Salt and freshly ground black pepper to taste
Small French baguette, sliced crosswise into 1/2-inch pieces
4 ounces Swiss cheese, grated on the large holes of a box grater

Melt butter in a heavy pot on medium-low heat.
Add onions. Spread them out in as thin a layer as possible.
Cook, stirring occasionally, until the onions are golden brown, beginning to caramelize, about 1 hour.
Sprinkle flour over onions, and stir to coat.
Add cider, stock, and thyme, and bring to a simmer.
Cook, partially covered, for about 30 minutes, to allow the flavors to combine.
Season with salt and pepper to taste.
Ladle soup into oven-safe serving bowls and place one slice of bread on top of each.
Layer each slice of bread with ¼ cup grated cheese.
Place bowls on a cookie sheet and broil in the preheated oven until cheese bubbles and browns slightly.

Recipe Source: North Dakota State University Extension