Larger sets will make smaller bulbs and are best suited for producing green onions. Small sized sets produce larger mature bulbs. Select sets that are firm and not yet sprouted. Growing onions from seed requires a long period to produce either green onions or dry bulbs, and generally this practice is not recommended for most home gardeners unless started early indoors. See Related Publications for more information on starting seeds indoors.
Many garden centers offer a small selection of onion transplants in early spring.
If dry onions are desired, plant them 1 to 2 inches deep, but 3 to 4 inches apart. Some gardeners make one planting and then pull plants for green onions, leaving one plant every 4 inches for mature bulbs. Cover the sets or firm in transplants and water thoroughly. Summer Care Cultivate shallowly to control weeds, particularly during the early part of the growing season. Additional water during dry periods will ensure a good yield.