It’s a simple matter to learn how to grow onions in your own garden.

Often dismissed for their sharp taste and tear-inducing smell, onions are a versatile vegetable for any garden. They can be pickled, grilled, sautéed, fried (of course!), and boiled, adding texture and flavor to a number of dishes.

The versatility of the onion’s use in your dishes is matched only by where the sprout can grow. The onion grows in nearly any climate, so long as the season is conducive to growth.

There are a variety of onion types, with brown, white, yellow, and red onions being among the most popular types. Leeks and shallots are also members of the onion family, and can be just as useful in your cooking as their colorful brethren. All told, there are more than 400 species of onions, so it’s important to know your which one(s) you want in your garden before you learn how to grow onions.

For our purposes, we’ll stay with bulbing onions as these are the most common type, and the most useful with other foods.

How to grow onions from seeds

  • Onion seeds should be planted in February or March, unless you’re in a warmer climate, and then you should plant them in September or early October.
  • Onion seeds should start indoors first, 8 to 10 weeks before the average frost-free date for spring planters or 8 to 10 weeks before it starts getting chilly for fall planters.
  • Soak the seeds in a compost tea for around 15 minutes and then sow quickly in half-inch deep flats with a damp sterile mix. Germination of the seeds should occur in around 5 days in warm (65 to 85 degrees Fahrenheit) soil.
  • Once the seeds have sprouted, transplant them to a space of 1-inch and move to a cool (60 to 65 degrees Fahrenheit) but sunny area, and apply a weak fish emulsion fertilizer on a weekly basis.
  • 2-3 weeks before the expected last frost or first chill, move the seeds to your garden, being careful not to bruise the root or neck of each plant. The soil should be near-neutral (pH 6.0 to 7.5), weed free, and retain moisture but still drain well. Common fertilizers with plant food, nitrogen, phosphate, and potash will work, but well-composted soil is a perfectly viable alternative. Seeds should be planted 8 inches deep, spaced two to six inches apart.
  • Weeding is a must while cultivating onions since the vegetable produces grass-like tops instead of leaves.
  • If rain is scarce, water thoroughly once a week
Harvesting and storing bulb onions grown from seeds
  • Onions are ready to harvest when their tops turn yellow and fall over. (If you’re eager to enjoy your onions, you can bend over the tops yourself to stop growth.)
  • Dig carefully, being sure not to bruise the bulbs in the process (they’ll rot more quickly otherwise).
  • Allow the harvested onions to dry in a warm and ventilated space for two weeks (a shed or porch floor will do fine).
  • Use any onions that produced flowers first. Trim the tops of the others and store in mesh bags in a dry, cool place (35 to 40 degrees Fahrenheit) and use as needed.
  • Onions may last only a few months, so be sure to chop and freeze any that have gone unused.
If you decide to grow onions from sets, the process is largely the same as for seeds, but you should carefully select the right size of the sets. Dime-sized sets work the best, producing the most consistently sized bulbs. These will grow faster than seedling onions, but will still require the same amount of care that seedlings do.

Got other ideas about how to grow onions? Leave us a note in the comments below.