Can you plant onions in the fall? It depends on how far south you are

Southern extension pages treat fall as the main planting time. Clemson's table gives the South Carolina coast September 15 to November 15 for sets and October 1 to November 15 for transplants. In the Piedmont both run September 15 to October 15. NC State puts fall planting at about September 10 to October 15, with spring planting from about January 15 to February 25 as the other option.

Source: Clemson HGIC, Onion, Leek, Shallot and Garlic, checked October 9, 2026; NC State Extension, Bulb Onions, checked October 9, 2026.

Texas runs later. Texas A&M AgriLife sows onion seed October through December and sets transplants in January and February, with bulbs by May to July. These are short day onions. Clemson says they bulb at about 12 hours of daylight and suit all of South Carolina, and long day types don't succeed in the South.

Source: Texas A&M AgriLife Extension, Onions, checked October 9, 2026; Clemson HGIC, Onion, Leek, Shallot and Garlic, checked October 9, 2026.

• Sep 15 to Nov 15onion sets, South Carolina coastClemson HGIC, Onion, Leek, Shallot and Garlic, October 9, 2026
• Sep 10 to Oct 15fall planting, North Carolina (approximate)NC State Extension, Bulb Onions, October 9, 2026
• Oct to Deconion seed in TexasTexas A&M AgriLife Extension, Onions, October 9, 2026
• 1 in or lessset size that helps prevent boltingClemson HGIC, Onion, Leek, Shallot and Garlic, October 9, 2026

Illinois Extension plants onions as soon as the garden can be tilled in spring, usually late March or early April. Maryland says to plant onion sets in spring for early onions and in fall for perennial or multiplier types. Its shallot and multiplier cloves can go in from late September through mid-October and may make larger bulbs than a spring planting.

Source: Illinois Extension, Onion, checked October 9, 2026; UMD Extension, Growing Onions in a Home Garden, checked October 9, 2026.

There is a northern fall option for bulb onions, but it starts in summer. Utah State says onion seed can be planted in mid to late August for overwintering, using special varieties, mulched late in the year, and ready in June or July. Iowa State plants Egyptian onion bulbils in fall for overwintering.

Source: USU Extension, How to Grow Onions in Your Garden, checked October 9, 2026; Iowa State Extension, The Other Onions, checked October 9, 2026.

Windows are each page's own words. Zones are for the example zip in the 2023 PRISM data, not the official USDA map; check your own zip with the zone finder.

Source: Clemson HGIC, Onion, Leek, Shallot and Garlic, checked October 9, 2026; NC State Extension, Bulb Onions, checked October 9, 2026; Texas A&M AgriLife Extension, Onions, checked October 9, 2026; UMD Extension, Growing Onions in a Home Garden, checked October 9, 2026; Illinois Extension, Onion, checked October 9, 2026; USU Extension, How to Grow Onions in Your Garden, checked October 9, 2026.

1. 1

   Find your zone and state page

   Type your zip into the zone finder, then read your own state's extension onion page. The zone alone won't give you a date.

2. 2

   Check the onion type on the package

   Short day onions are the fall choice in the South. Multiplier onions and shallots are Maryland's fall option.

   Source: Clemson HGIC, Onion, Leek, Shallot and Garlic, checked October 9, 2026; UMD Extension, Growing Onions in a Home Garden, checked October 9, 2026.

3. 3

   Sort the sets by size

   Keep sets an inch or less across for bulbs. Larger ones suit green onions.

   Source: Clemson HGIC, Onion, Leek, Shallot and Garlic, checked October 9, 2026; Illinois Extension, Onion, checked October 9, 2026.

4. 4

   Count the bed

   Pick Other in the planting calculator, type 3 inches apart and 12 between rows. A 4 x 8 bed holds 128.

   Source: Clemson HGIC, Onion, Leek, Shallot and Garlic, checked October 9, 2026; Illinois Extension, Onion, checked October 9, 2026.

5. 5

   Write the date down

   Note the planting date and set size, so you can tell next spring whether early planting or big sets caused any bolting.

Texas and Clemson space bulb onions 3 inches apart. Illinois uses 2 to 4 inches with rows 12 to 18 inches apart. Maryland goes from 2 inches for green onions to 8 inches for large bulbs.

Source: Texas A&M AgriLife Extension, Onions, checked October 9, 2026; Clemson HGIC, Onion, Leek, Shallot and Garlic, checked October 9, 2026; Illinois Extension, Onion, checked October 9, 2026; UMD Extension, Growing Onions in a Home Garden, checked October 9, 2026.