A rich and thoroughly fine soil is needed for the onion. It must be kept entirely free of weeds and grass. It does not need much space. Rows 18 inches wide will be ample if cultivation is done by hand.
For green onions during late fall and winter, put out sets from early September to late October, depending on location.
Do not depend on these for mature onions the following summer. They do not keep as well as those grown from seed or plants. Even in the region just above the Cotton Belt they will probably be hurt little by cold before Christmas and sometimes they will be safe later than that.
In this territory put out sets in late August to early September. Put sets 2 to 3 inches apart, barely covering the bulb, with tip of the bulb just under surface of soil.
For the main crop of onions to mature in early summer and to carry through winter, plant seed in September or October, or in mid-winter in the Cotton Belt. Above this line, late-winter planting in February and March is the best time.
When planted in fall, pull soil to plants as they grow so that when freezing weather comes they will be somewhat protected. Even if hard freezes should kill the tops above ground, onions will come out again. If you buy plants, set them out in January in the Lower South, February in Mid-South, and March in Upper South. Sow seed thick, and thin to one plant to each 2 to 4 inches.
After pulling, let lie in the sun just long enough for moisture and any dirt to dry. Then cut off tops about an inch above the bulb and store, in thin layers in a cool, dry place. If you have only a few onions, leave tops on, tie in small bunches, and hang on nails under shelter.