Three Ways to Grow Onions in Your Vegetable Garden

From sweet to bitter, onions make the perfect addition to almost any platter. (1195798/pixabay)

Onions are wonderfully versatile vegetables. Caramelized onions can sweeten up your cheeseburger, and crunchy-fresh red onions can add a bite to your salad. But just like with tomatoes, if you buy your onions at the supermarket, you’re buying cultivars that were chosen because they last long and ship well, and you’re missing out on a whole world of flavor.

Growing onions in your garden is easy, and it gives you the opportunity to savor all this veggie has to offer. You’ll never go back!

There are three main ways to grow onions in your home vegetable garden, and each method has its advantages and disadvantages.

Read on to find out about each of the three onion planting methods, and how to choose which one is right for you.

Onion Set
Onion sets are really just dormant onion bulbs. (payamona/Getty Images)

Method #1: Growing Onions from Sets

Onion sets look like tiny onions and are actually dormant onion bulbs. You can buy onion sets in the spring at your local gardening center, and hardware stores and home improvement centers often sell them as well.


This is the most popular way to grow onions. That’s because it’s the easiest way, and requires the least work.


The most obvious downside to buying onion sets is the cost. Onion sets cost a great deal more than seeds, so you are paying for skipping the work.

You will also likely be far more limited in the onion varieties you can choose from. In fact, a lot of stores simply label onion sets by color rather than by cultivar name, so you just know you’re getting a “white” onion, rather than which specific type.

How to Grow Onions from Sets:

To grow onions from sets, choose sets that are about the same diameter as a dime. Onion sets that are too large will go to seed too quickly and give you small onions.

Store the sets in a cool, dry place until planting time, which will be two to four weeks before your area’s last expected frost.

To plant your onion sets:

  • Dig a shallow furrow for your onion sets. The furrow only needs to be deep enough so that the tip of the onion set will be right at the surface of the ground after you fill it in. Place the sets into the furrow pointed-end-up, about 4″ to 6″ apart.
  • Cover the onion sets with dirt, and pat the dirt down gently.
  • Consider fastening some sort of protection over your onion sets to prevent animals from digging them up. Raccoons, gophers, rabbits, and even dogs have been known to swipe onion sets. Chicken wire staked to the ground makes a pretty good digging preventer.

Onion Seeds
Onion seeds are the least expensive of the three methods but can take the longest time. (bdspnimage)

Method #2: Growing Onions from Seeds

Onion seeds are available in local gardening centers, as well as from seed catalogs and several websites. If you order seeds from a catalog or online, make sure you’re ordering a type of onion that is suited for where you live.


This is the least expensive of the three methods, so if you want to grow a lot of onions, you may want to go this route. Growing onions from seed also gives you the most possibilities in choosing cultivars, as long as you choose onions that will survive in your climate.


This method takes the longest and is the most work-intensive.

Buying the Right Type Onion Seeds:

Onions automatically start growing when the spring days reach a certain length, and onions are categorized by their “day length,” or how long the days are when they will start to grow.

Onions are either short, intermediate, or long day cultivars; and each region of the country is suitable for only certain types of onions.

Before you buy onion seeds from a non-local source, find out what the day-length is where you live. In general:

  • Short day onions do best in the Southern U.S. (Southern California, Florida).
  • Intermediate day onions do best in the central latitudes (Kentucky, Iowa).
  • Long day onions thrive in more northern latitudes (New England, Washington State, Michigan).

If you aren’t sure, your local gardening center or university cooperative extension can tell you.

How to Grow Onions from Seeds:

If you’re growing fast-maturing onions, you can sow the seeds directly into your garden 1/4″ deep, as soon as the soil temperature has reached 50° Fahrenheit. Space seeds 1/2″ apart, and space rows 12″ to 18″ apart.

For other types of onions, you will need to start your seeds indoors and transplant the seedlings into your garden. Here’s how:

  • Start seeds indoors eight to 10 weeks before the last frost date. Follow these instructions for starting seeds indoors.
  • Once the sprouts have grown tall, trim them down to about 4″ to 6″ high with scissors. Toss the trimmings on your salad or baked potato for some added flavor!
  • Follow the instructions below for transplanting onion seedlings.

Onion Seedling
Onion bulb transplanting is easy because most of the sprouting is already done and ready for full growth! (bdspnimage)

Method #3: Growing Onions from Seedlings

Another way to grow onions is to transplant young seedlings into your garden. Seedlings are for sale in garden centers in late spring.


This method is a procrastinator’s dream-come-true. Even if you missed the spring planting season, you can still have onions this year!

Growing onions from seedlings also takes the least time commitment of the three methods, and requires little work.


Buying seedlings is the most expensive of the three methods.

How to Grow Onions from Seedlings:

  • Choose a green, healthy-looking flat of onion seedlings.
  • You can transplant a week or two before the last frost date, but after the risk of any hard freezes has passed.
  • Set the plants outside for a few hours each day for about a week before you transplant them. This will “harden” the plants and prepare them to survive outdoors.
  • Trim the sprouts to about 4″ to 6″ high with clean scissors on transplanting day.
  • Dig a trench for the seedlings that will be deep enough to bury them slightly deeper than they were sitting in the flats.
  • Carefully remove the seedlings from the flats and gently loosen the dirt off of the roots.
  1. Place the seedlings in the trench, about 4″ to 6″ apart.
  • Cover the roots with soil until the ground is level, gently pat the dirt, and water the seedlings.

Now you’re ready to grow delicious onions!

Further Reading


  1. An interesting article about growing onions, but how about one on how to eradicate wild onions in my perennial beds. Between the weeds and the onions this spring, I can’t even find some of the perennials.

    Love your show–I watch it every week.


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