Decrease your grocery list by planting onions

White onions with green tops growing in a raised bed.
Posted by

Do you grow peppers and tomatoes every year? Are you ready to try something different (or maybe in addition to!) the same-old, same-old? Then you should try growing onions this gardening season. With just 30 square feet of planting area, you could grow the bulk of the onions you cook with this year.  

If you read my recent article on how to grow potatoes, growing onions is a very similar process, but easier.

Onion availability

There is one small caveat to growing onions, availability. Since the pandemic began, growing staple foods in your own backyard is a hobby that has increased in popularity. In 2021, onion bunches – otherwise known as sets – sold out at local gardeners in two weeks. 

If you are going to try growing eyes, visit the garden centers now. A set is made up of individual slips that look like miniature leeks and are about the thickness of a pencil. They usually come in sets of 50. Get several bunches, they’re cheap. If you overbuy, you can give some away!

Preparation and Planting

  1. Prepare loosened garden soil
  2. Add some granular, slow-release, or pelletized garden fertilizer according to label instructions
  3. Add 1-2 inches of compost

Make small holes with your fingers in the prepared bed, then plant the slips 6 to 8 inches apart and 2 inches deep. Rows should also be about 6 to 8 inches apart. The roots and some of the bottom portion of the slip should be covered with soil. To gently secure the plant in the bed, cup both hands around the base of the slip and compact the compost just enough to hold the slip in place. Water them in.

Prevent Weeds

Onions are extremely sensitive to weed pressure. If you’re new to growing onions, make planting spaces wider (8 inches) to reduce the likelihood of damaging a slip while weeding with a hoe. If you weed with a hoe once a week for the first 4 weeks, even if it looks like there are no weeds there, you will grow big fat onions with no weed pressure. Get them while they’re small! 

With proper soil preparation that is amended with compost and fertilizer, frequent weeding, and a well-watered bed, your onion slips and time will produce a nice onion crop. To cure onions, consult the Illinois Vegetable Garden Guide.

PHOTO CREDIT: Onion; Nick Frillman, University of Illinois Extension

ABOUT THE AUTHOR: Nick Frillman is a Local Foods and Small Farms Educator serving Livingston, McLean & Woodford counties. A fourth-generation graduate from University of Illinois, Frillman has a B.A. with a double major of Political Science and Spanish and a M.S. in Crop Science with a focus on crop production. Before joining Illinois Extension, Frillman completed a field season of CSA and farmers’ market style production at a small “beyond-organic” vegetable farm in Sandy, Oregon.