What is the proper way to plant onion seeds?
Plant onion seeds as soon as the ground can be worked in spring (late March or early April in southern Iowa, early to mid-April in central Iowa, and mid to late April in northern portions of the state). Plant seeds in rows 12 to 15 inches apart. Cover the seeds with one-half to three-quarters inch of soil. When the seedlings are 2 to 4 inches tall, thin the planting. For large, dry onions, plants should be spaced 2 to 3 inches apart after thinning. A full season of growth is needed for mature onions.