How Far Apart To Plant Onion Sets

You are hither

Planting Onions in the Home Garden

By Richard Jauron
Horticulturist
Iowa State University Extension

Onions are one of the most popular vegetables in the home garden. They can be grown for green onions and dry bulbs.

Onions are easy to grow. They perform best in well-tuckered, slightly acidic, fertile soils in full sun. Heavy soils can be improved past incorporating organic matter, such as compost, into the soil. Onions require higher fertility levels than nearly other vegetables. Apply 1 to 2 pounds of an all-purpose garden fertilizer, such as 10-x-10, per 100 foursquare anxiety and till into the soil prior to planting. Iv to five weeks after planting, sidedress with additional fertilizer. Sprinkle 1 pound of an all-purpose garden fertilizer per 100 feet of row. Identify the fertilizer in a narrow band well-nigh 2 to iii inches from the base of the onion plants.

An of import attribute of onion evolution is photoperiod or day length. Photoperiod, along with temperature, control bulb formation. The cool temperatures and short days of early spring promote leaf and root growth. Bulb germination begins when a certain day length is reached. Curt-day onion varieties begin to form bulbs when they receive xi or 12 hours of daylight, intermediate-day onions need 12 to 14 hours of daylight, and long-mean solar day varieties require fourteen or more hours of daylight. Long-twenty-four hours varieties are the best choice for gardeners in Iowa and the upper Midwest. Short-day varieties in Iowa volition begin to bulb when the plants are small and will non produce big bulbs. Small bulbs can too exist expected if long-solar day varieties are planted in late jump in Iowa.

Onions may be grown from seeds, sets and plants. The planting method selected is based on price, use, availability and planting ease.

Seedsouthward

Growing onions from seeds may be the nigh difficult planting method. Nevertheless, information technology is the least expensive.  Germination may be sporadic, plant growth is slow, and weeds may be a problem. Plant onion seeds as soon as the footing can exist worked in leap (late March or early April in southern Iowa, mid-April in northern portions of the state). Institute seeds in rows 12 to fifteen inches apart. Cover the seeds with ane/2 to iii/4 inch of soil. When the seedlings are 2 to iv inches tall, sparse the planting. For large, dry out onions, plants should exist spaced ii to 3 inches autonomously after thinning.  A full season of growth is needed for mature onions.

Sets

Sets are small onion bulbs that were grown the previous twelvemonth, harvested, stored through winter, then distributed to garden centers in early on bound. Specific onion varieties are usually non available. They are sold simply as blood-red, white or yellowish onion sets. Since the variety is unknown, the flavour, utilize, and keeping quality of onions grown from sets varies considerably. Before planting sets, separate the bulbs into ii size groups -- those smaller than a nickel in diameter and those larger than a nickel. The larger sets ofttimes bolt (produce a blossom stalk) and don't produce good-sized bulbs. Use the larger sets for green onions. The smaller sets tin exist allowed to develop into mature onions.

Plant sets in early leap every bit shortly as the ground can be worked. Sets should be planted at a depth of i to 1 1/2 inches in rows 12 to 15 inches apart. For dry onions, constitute the sets two to 3 inches apart. Sets grown for green onions can be planted closer together.

Plants

Plants are onion transplants grown in southern areas of the U.s. in winter, bundled into bunches of 50 to 100 plants, then shipped to garden centers in early on spring. Onion varieties are available when purchasing plants.

Select healthy green transplants and plant them one to 1 1/two inches deep in rows 12 to 15 inches apart. To produce large, dry onions, place the plants 2 to 3 inches autonomously. Plant them as soon every bit the ground can be worked in spring.

Suggested onion varieties for home gardens in Iowa include Copra (main season, yellow-brown skin, excellent storage), Candy (yellowish-brown peel, globe-shaped, short term storage), Red Burgermaster (bright red, world-shaped, good storage), Sweet Sandwich (belatedly season, xanthous-brown skin, fantabulous storage), and Walla Walla Sweetness (late season, yellowish-brown pare, short-term storage).

Contacts :
Richard Jauron, Horticulture, (515) 294-1871, rjauron@iastate.edu
Jean McGuire, Extension Communications and Marketing, (515) 294-7033, jmcguire@iastate.edu

Source: https://www.extension.iastate.edu/news/2007/mar/071601.htm

Share this post