Bunching onions are a popular addition to many home gardens. Most people know these bright green clusters of onions as scallions or green onions. Bunching onions grow readily during the cooler spring temperatures in well-draining, rich soil. Gardeners who plant bunching onions often plant them among the first of the spring vegetables as soon as they can work the soil in the spring. Depending on the variety, harvest will be either late spring or early summer.
Work a sunny garden area as early in the spring as possible. Till the soil with the spade to loosen it down to a depth of 4 to 5 inches. Add 1 inch of compost and 3 lbs. of fertilizer for every 100 square feet of growing area to the top of the soil. Work these materials in completely.
Plant the bunching onion seeds under a half-inch of soil with each seed spaced 3 inches apart. Space the rows between 12 and 18 inches apart. Water well after planting and keep the seeds evenly moist.
Apply mulch around the onion greens to help control weeds and keep the soil moist. Pull weeds by hand as they appear among the onions.
Watch the onion greens for signs that they are ready for harvest. Indications of readiness include tops that are at least 6 inches tall and dry tops that begin to lean over to the side. Carefully pull the oldest onions up, taking care not to disturb younger onions that are not yet ready to harvest.
Leave the onions laying on the soil in the shade for two to three days after pulling. Move the onions to a sheltered garage or porch for between one and two weeks to cure. To store after curing, leave the tops on or cut them down to approximately 1 inch above the bulb.