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How To Plant Onions (Step By Step Guide)

by Idris Ya'u
This article was fact checked.
Helpful: 100%

In this article, I will be explaining 3 ways by which onions can be planted. First of all, you need to find out the varieties which grow well in your region. Due to the fact that the lengthening days of late spring promote the transition from growing leaves and roots to the business of forming bulbs, the types of onions that grow well in Northern states are different from those in the South.

Catalog descriptions and seed packets help reveal the varieties that work well in short-day regions, intermediate- day regions, and long-day regions. The short-day regions have their bulbs formed when day length is about 10 – 12 hours, the intermediate-day regions have their bulbs formed when day length is 12 – 14 hours while the long-day regions have their bulbs formed when day length is 14 – 16 hours.

Explained below, are the ways by which you can plant your onions:


Sets are tiny onion bulbs grown from seeds and pushed into dormancy at an immature stage. They resume growing once they are planted in the garden.

Of all the three planting techniques, sets are known to be the easiest and also a good way to produce many big onions for storage. To plant onions using sets, plant the sets 2 – 4 weeks before the average last frost date. You can plant onion sets in fall or winter.

This is done by placing the sets in a shallow furrow and covering them with enough soil to leave their pointed tips at the soil surface. Space the onions 4 – 6 inches depending on the mature size of the variety.

However, the sets can be placed closer together initially and harvest thinnings for use as green onions. A disadvantage of sets is the limited choice of varieties.

Tip: Learn more on how to grow onions at home without seeds


Using a greenhouse or indoor light setup, you can produce bundles of bare-root onion or you can as well purchase them from a retail store. In the North, the seeds should be down in a flat of seed-starting medium 8 – 10 weeks before the last frost for planting outdoors close to 6 weeks later.

In the South, thin the emerging seedlings in the flat to stand nothing less than a half-inch apart in rows about 2 inches apart for the seedlings to be easily separated at transplant time.

The seedlings should be hardened off by setting the flat in a sheltered spot outdoors for few hours a day. In a gradual process, acclimate them to a full day of direct sunlight.

On the day the seedlings are to be planted, lift them carefully from the flat and shake the soil from the roots. Dig a trench and slightly place them in a way deeper than they were in the flat.

Related: How To Harvest Onions And Garlic Step By Step


To plant onions using seeds, saw your seeds about a month before the frost-free date and then again every few weeks through fall. This is done for continual harvests. In the South, the season is fall through spring so start with fresh seeds which are no more than one year old. This is because they lose viability quickly in storage.


I hope this article helps you understand how to plant onion. I would like to hear from you. So, Let me know if you have any questions about planting onions. Also, learn how to grow green onions in water.

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