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Fall Onion Planting in Carolina

By Aileen Clarkson ; Updated September 21, 2017
Short-day onions are best for the Carolinas.

Onions grow best during cool weather and are tough enough to withstand moderate freezes. North Carolina and South Carolina have the ideal climate for these pungent vegetables, and onions can be grown in both states almost year-round. Onions are members of the allium family and are related to garlic, leeks and shallots. After the onions have been harvested and cured, they can be eaten raw, fried, pickled, boiled, creamed ... the list is endless. Onions are one of the most versatile kitchen vegetables.

Dig up the top 6 inches of the garden bed to loosen the soil.

Add a 2-inch layer of compost and work it in. Water the bed so that it is moist but not soaked.

Plant a short-day variety of onion in a location that has about 12 hours of daylight. Grow intermediate onions if you are in the colder parts of the Carolinas.

Plant onion sets in rows 1 to 2 feet apart, 1-1/2 inches deep. Plant onion seeds 1 to 2 feet apart but only 1/2 inch deep. Place seeds or sets 1 to 2 inches apart if you are growing green onions. Space bulb onions 3 inches apart.

Water every day for the first week, then at least once a week. Stop watering about a week before harvest so that the onions have time to harden off.

Weed the onions for the first month, but stop cultivating when the roots have begun to extend. Work the soil away from the bulbs gradually, starting a month before harvest. Ideally, the bulbs will be 1/3 above the ground by harvest time.


Things You Will Need

  • Compost
  • Hose
  • Hoe


  • Consider planting onions in raised beds, which have better drainage and make it easier to harvest the bulbs.
  • Long-day onions do not grow in the South, according to Clemson University.


  • Avoid onion sets that are more than 1 inch in diameter because they are more likely to bolt (produce a flower stalk).
  • Onions prefer fertile, well-drained loamy soil that has a lot of organic matter, according to the North Carolina State University.

About the Author


Aileen Clarkson has been an award-winning editor and reporter for more than 20 years, earning three awards from the Society of Professional Journalists. She has worked for several newspapers, including "The Washington Post" and "The Charlotte Observer." Clarkson earned a Bachelor of Arts in journalism from the University of Florida.