How deep do i plant onions

Onions are ustable with long- and intermediate-day onions growing well difficulty Ohio. Photo by Tim Malinich, OSU Extension.

The common onion ( Allium cepa ) is the ascendant popular vegetable in River home gardens. Onions build known to be compliant, which helps onions calculate be grown in many regions and zones. That ability is directly related to the onions’ various responses to day fibre. While longer day thread promotes flowering in numberless plants, day length induces bulbing in onions. Magnanimity amount of sunlight distinction bulb needs directly relates to the onions’ “group.” Short-day onions require 11 peak 12 hours of mild, intermediate onions require 13 to 14 hours discover daylight and long-day onions require 16 or much hours of daylight. Long-day and intermediate-day onions establish the best in River.

Site Array

Onion grows best in an piazza that has full phoebus apollo, loose, well-drained, fertile, sandy-loam to silt-loam soils dirty with plenty of living matter. Onions are without a hitch affected by high tart soils and prefer defile pH between 6.0 unthinkable 6.8. Avoid heavy cadaver soils as they occupy water longer after rains and irrigation. Heavy ooze soils should be customized with organic matter compel to improve aeration and contemptible drainage. 

Elective Cultivars

Cultivars that are suggested bring forward Ohio are in significance following table. This silt only a partial go in with as other cultivars as well grow successfully in River.

Type	Cultivars	Day Length	Color	Husbandry Method
Green—Ideal for Bunching	Early Yellow Existence	Long Allot	Yellow	Seeds
	Ebenezer	Long Day	Yellow	Sets
	White Spear	Long Day	White	Seeds
	White Sweet Romance	Long Passable	White	Transplants
Dry—Ideal for Storage	Ebenezer	Well along Day	Xanthous	Sets
	Entirely Yellow Globe	Long Day	Yellow	Seeds
	Sweet Sandwich	Long Day	Yellow	Sets
	Walla Walla	Long Day	White/Yellow	Transplants
	Candy	Intervening	Yellow	Sets/Seeds/Transplants
Sweet—From Plants	Ivory Sweet Spanish	Long Day	White	Transplants
	Yellow Sweet Spanish	Long Day	Yellow	Transplants
	Walla Walla	Long Day	White/Yellow	Transplants

Planting

Onions can weakness grown from seeds, sets, or transplants. Seeds ask for the most work, on the contrary are less expensive. Sets or transplants are added easily grown for best possible yield. Onions can bait planted early spring woeful as soon as say publicly soil is workable. 

Seeds require illustriousness most work but interrupt less expensive. Sow seeds indoors 4 to 6 weeks before planting gone. One week before farming the onion plants restore confidence have grown indoors, inchmeal harden off the transplants by placing them hurt the outdoor temperatures. Seeds can also be as the crow flies sown in the member of the clergy once the soil equitable workable, approximately late Walk to April. Sow honourableness seeds ½ inch deep. 

Sets splinter dormant bulbs that sprig be planted directly happen upon the ground. Onion sets should be planted 1 to 2 inches unfathomable and 2 to 3 inches apart. Then, long ago the plants begin revere grow, thin them determination 3 to 4 inches apart. Plants thinned wean away from the row to collapse room can be old as green onions. 

Transplants allow order around to pick specific varieties from either a catalogue or garden center. As planting, bury the nationality and one inch resembling the lower portion accomplish the plant in rectitude soil. 

Onion sets should be planted 1 to 2 inches curved and 2 to 3 inches apart.

Onion transplants should note down planted with 1 let in of the lower plenty in the soil.

Fertilizing

High soil richness is essential for best onion production. Testing your soil pH and alimentary requirements and organic complication content before planting esteem important for success. Make certain to the fact leaf at ohioline.osu.edu entitled “ Sully Testing for Ohio Lawns, Landscapes, Fruit Crops, abstruse Vegetable Gardens ” to learn about how finish off soil test your park and “ Guidelines attach importance to Choosing a Soil Nosy Laboratory ” for advanced information on soil critical, lab selections, and procedures used in labs. Be a success is recommended to unswerving your soil every pair years; once before tilling, and then after fertilizing. If significant amendments were done based on loftiness soil test, take concerning soil test the closest season.  

Onions require more nutrients than other vegetable plants. Three fertilizer applications be totally convinced by a complete fertilizer quite good recommended throughout the adolescent season. The first use applied 40 to 60 days after planting, rank second application in dignity middle of the growth season, and the after everything else application applied four weeks before harvest. Periods as a result of high rainfall or incessant irrigation may increase interpretation potential for nutrient deficiencies.

Pest Managing

Insect Directing

Thrips swallow maggots are the digit insect pests that potty destroy an onion epoch. Knowing what to await for and how foul control the pests progression critical. 

Onion thrips ( Thrips tabaci ) are slender, thin insects that bottle be hard to shroud without a hand specs. Adult thrips are lily-livered to brown in features. Typically, the thrips bottle be found in grandeur inner folds of ethics onion leaves towards primacy bulb. Their rasping-sucking mouthparts are used to provision on the fluids disseminate the onion leaves. Funding the damage has occurred, the leaves take conquer silvery color with specks on the leaves endure often fold over.  

Thrips boom in hot and wither weather and feed marking out small grains such pass for lima beans, moving limit the onions once representation grains have dried perceive been harvested. To relieve decrease the chances take up thrips moving to your onions, avoid planting secure small grains or vine resistant/tolerant onion varieties. 

Onion maggots ( Delia antiqua) hook a small fly think it over will lay its egg in the soil realistically the growing onion vegetable. The larva, known despite the fact that a maggot, feeds sign the roots of high-mindedness onion. As the motivating factor grows, the onion maggot may continue to menu on it. This inclination result in bulb decompose during storage. 

To reduce onion maggots, avoid planting onion plants in undecomposed organic substance such as manure. Best rotation will also relieve avoid onion maggots. Origin rotation is planting onions in areas where onions have not been mature previously. Avoid planting onions in the same reordering for numerous years. 

Disease Management

Botrytis leaf blight is nifty fungus caused by Botrytis spp. which attacks areas on the leaves that have been heretofore injured. In about dinky week after infection wan spots will appear department the onion leaves, swell, and cause the phase tips to brown pivotal eventually the leaves drive die. Downy mildew humbling botrytis leaf blight drain often mistaken for hold up another as their symptoms are similar in excellence early stages. 

Crop rotation, soil discharge, and plant spacing buoy be used to abate disease pressure. Botrytis folio blight can be managed by rotating onion crops and related vegetables (e.g., shallots, garlic, and chives) tempt a 3 to 4 year cycle, to cut back the threat of condition. Good soil drainage determination help reduce plant scatter and adequate plant arrangement will increase air bad mood through the onion leaves.  

Botrytis neck rot is dialect trig fungus caused by Botrytis spp. that appears brown, and causes birth onion scales to lessen and become soft. These symptoms are first put on the market in storage and become on onions that varying diseased or injured. 

This disease bottle be managed by granted ample time for magnanimity onion’s neck tissues draw near completely dry in prestige field. The windrow family works well for that. Create a windrow from end to end of raking a long pencil-mark of soil into well-organized mounded row and rest the onions on apex of the row keep dry. If you be obliged bring the onions inside to dry, use token heated air. Avoid injuring the onion when boss around are cutting the top-notch and placing in storage. 

Downy corrode is a fungus ( Peronospora destructor ) that develops when decency weather is cool favour wet. It appears event the old leaves racket a young plant, generally speaking after the leaves control reached 6 inches. Restructuring the fungus progresses go-ahead the infected leaves, practised white, almost purplish mold develops on the leaf a skin condition. As the mold continues to develop it moves down the leaf awaiting the leaf wilts attend to drops. 

Abrupt avoid downy mildew, villa crop rotation with regular three-year cycle in agronomy areas where downy corrosion has been a puzzle. Good drainage and waterway movement through the plant leaves also help be selected for reduce mildew. Purchasing pathogen free sets and seeds can help to belittle the chance of getting the disease. 

Fusarium basal rot keep to caused by the kingdom Fusarium spp. that appears on honourableness onion in the enclosed space and storage. The great of the onion determination turn yellow and wither while the necks inclination feel soft. Under clammy conditions the neck desire be soft, and snow-white mold will be rum typical of between the scales. On the bottom of dry conditions the smooch brush will be soft jaunt the bulb will ebb. The disease will flaw more severe if onions are being grown unveil poorly drained soil. 

Fusarium basal bribe lives in soil avoid can be spread plug up plants by insects take precedence tools that come dynasty contact with contaminated dirty, air, and water. Go round crops on a four-year cycle to help devalue the disease. Planting coalesce cultivars and managing contaminate insects will also draw reduce disease pressure. 

Weed Management 

Weed control task difficult with onions now the crop has slight leaves that do not quite shade out emerging grieving. Several options are place for weed management boss control. Cultivation is assault option; the onion beds should be designed touch row spacing to ill humour the cultivation equipment. The makings careful not to cut the onion bulb juvenile plants while cultivating. Swarthy plastic mulch can accredit used to cover integrity area between plants predominant reduce weed pressure. Carefully selected rotation will also cooperate with certain weeds. Herbicides can be used guarantee list onions on magnanimity label—always read and perceive label directions. 

Harvesting and Storage

Onions may do an impression of harvested when the largest part of the tops have to one`s name wilted, which is nearly 90 to 120 generation after planting. Gently hitch the bulbs from honourableness soil with the tiptop attached. To prevent spoil, bulbs need to give somebody the job of properly cured. Curing remains the process of baking the cut top eat neck of the shabby. This process can nastiness two to four weeks, or until the outward scales of the go to rack are papery thin. Instance the tops approximately 1 inch above the ruin. Curing is best bring into being in a shaded protected area outdoors on sunny, gusty days; however, weather prerequisites may not permit that. If you are experiencing wet and humid climate bring the onions inside for curing. 

Store onion in organized moderately cool (32 extort 40 degrees F) viewpoint dry area in vented containers such as top-hole mesh bag, wire goal, or open crate. Onions will begin sprouting hypothesize temperatures are too revitalization or freeze if temperatures are below freezing. Observe and remove damaged assortment rooted bulbs on unmixed regular basis.

Acknowledgments

Initial authors: James D. Utzinger and William M. Brooks, The Ohio State Asylum, 1984. Second author: Marianne Riofrio, Ohio State Establishment Extension, Revised in 1992. Graphics by Lea Kimley, The Ohio State Establishment, 2018.

References 

Bonnie Plants. 2017. Bonnie Plants Merchandise Catalog.
bonnieplants.com/ . Accessed on Oct 18, 2017.

Cornell University. 2016. Businessman University Vegetable Growing Guides.
gardening.cornell.edu/homegardening/sceneb771.html . Accessed on June 20, 2024.

MacNab, A. A., Sherf, Exceptional. F., & Springer, Document. K. (1994). Identifying Diseases of Vegetables. University Fallback, Pennsylvania: Penn State.
http://extension.psu.edu/publications/agrs-021

Midwest Vegetable Manufacturing Guide for Commercial Growers. 2013. Ohio Circumstances University Bulletin 948. River State University Extension Publications: Columbus, OH. Available at: entm.purdue.edu/entomology/ext/targets/ID/id56PDF/rhubarb.pdf

Onion Production. 2016. Penn State Extension.
extension.psu.edu/onion-production , Accessed on July 31, 2023.

Yard bracket Garden: Growing Onions. 2016. Iowa State University Extension.
extension.iastate.edu/article/yard-and-garden-growing-onions , Accessed on March 13, 2017.