• Lay down your landscape fabric and burn holes in it for the onions to grow in. (Optional)  If you’re not using landscape fabric, just mark out your rows using a stringline, and start planting.

For onion plants:

• Make a hole in the soil and gently stick the onion in the hole.  Push the dirt up next to the roots so they can get good contact with the soil.

For onion sets:

• Just push the onion sets into the soil with your thumb every 6” or so.  As a general rule, you want to cover the seed (in this case the set) with the same amount of soil as the diameter of the seed.  So for onion sets, you’ll push them about an inch under the soil.

Plant In Beds

• I do most of my growing on 30 inch wide beds, which is what I recommend in my garden planning tutorial.  This is a better use of your space than if you are planting in rows.  I suggest putting 9 inches of space between your onion rows, and planting 3 rows per bed.  If you plant your onions 4 inches apart in row, you can get 450 onion plants in a 50’ long bed.  That is usually enough onions for the average-sized family for the year.  Occasionally, I have put in a wider bed with more rows in it, and it’s worked out just fine.  It’s just a little harder to weed the middle of the bed, because you have to reach it from the outside edge of the bed (see video below for a fuller bed of onions).

Keep Moist

• Keep the soil moist until the onions start to grow.  This can take a week or two depending on your soil temperature and weather conditions.  I will often set up a gentle sprinkler over my onions to make sure they’re getting the water they need until their shallow root systems are more established.  Once they are sprouting new growth, it’s fine to just water with a drip line.

Water and Weed

• Give your onions about 1” of water per week.  If it’s really hot, they might need more, but be careful not to overwater your garden.  Cultivate or weed once a week, and the weeds will be easy to keep up with.  If using the fabric, I typically only have to weed them about twice during the season, because eventually the onions get big enough that they grow up and shade out the weeds.
• When the onions start to bulb out, you'll want to remove the soil from around the onion bulbs, so that just the roots stay in the soil.  This is sometimes called "spooning the onions", because depending on the consistency of your soil,  you may have to use a spoon to pull the soil away from the base of the onions.  My soil is loose enough I can usually do it by hand, and usually most of the soil pulls away from the bulb as I'm doing my final weeding of the onions.

How To Harvest Your Onions

• When the onion tops start to fall over in late fall, that means they are almost done growing.  You can allow them to all fall over on their own, or if you want them to all be ready to harvest at the same time, you can knock the tops of the remaining onions down.  Once the stem starts to get smaller next to the onion, it means they are starting to dry up.  This is the time to harvest them.  To harvest, just pull up the onions, being sure to keep the storage onions separate from the non-storage onions, so you’ll know what onions to use first.  You’re also going to want to cure your onions, so pay attention to the weather and try to harvest them right before a dry windy spell.

How to cure your onions.

• It is important to dry and cure your onions so they will keep for a long time.  Lay them out in a dry spot out of direct sunlight and rain.  I like to lay mine on my front porch out of direct sunlight, and let the warm fall winds cure them.  You can store them in a mesh bag and hang them in your pantry, or you can braid them and hang them up.  It's important to note that while onion plants can handle some frost in the springtime, the onion bulbs that you plan to store cannot handle any frost.  So keep them dry and allow them to cure protected from cold temperatures.

How To Braid Onions

• When your onions are freshly harvested, and the stems are still green, you can lay three onions over top of each other, intertwining the stems close to the onion bulbs.  Then begin braiding the stems, and adding new onions to the braid as you go.  It is very similar to french braiding hair.  (See video below).  Allow the onions to finish curing outdoors, and then hang in a cool dry place for the winter.  I like to keep some hanging near my kitchen for decor and so I have easy access to them while cooking too.
• And that’s all their is to know about growing onions.  Onions are fun, easy and rewarding to grow, and growing a lot of them gives you a greater sense of food security for the coming winter.  Growing onions will also make a big dent in your grocery bill, not to mention that they are healthier for you than store-bought onions as well.