Growing your own onions is rewarding for avid vegetable gardeners and chefs. Red and yellow onion bulbs are not only inexpensive, but also simple to grow, since they need little maintenance once established besides water and sunlight. When growing large amounts, onions can be stored for entire seasons or pulled up and used whenever you desire.
Prepare the soil for planting by tilling it about 5 inches deep. It must be well-draining, loose and loamy. Remove any rocks or weeds from the soil.
Dig rows with the till or your hands for the onions to be planted, with each row being eight inches apart. The amount of rows you need depends on how many onions you are planting and the space you have. For example, the onion bulbs need to be at least 4 inches apart from each other, so if you are planting 12 onions, you need a 4-foot-long row or two 2-foot-long rows.
Dig a shallow hole in the row for each onion about 2 inches deep. Plant the red and yellow onion bulbs root-side-down in the holes. Keep in mind that the onion bulbs must be at least 4 inches apart.
Mound the soil up onto the bulbs, covering them with about 1/2 inch of soil on each side. They do not need to be completely covered or deep.
Use your garden hose to spray a gentle shower of water over the onions immediately after planting.
Layer about a inch of compost on the onion rows about a week after planting to fertilize the crop.