Sets received before planting time in your area can be stored in a dry, cool, airy, frost-free place until ready to plant.
Plant sets as early in spring as soil can be worked. Choose a sunny location with well-drained soil. Make shallow furrows, 1 1/2" deep and lightly press in onion sets about 3" apart in rows 1-2" apart, then cover with 1" of fine soil. For green onions (scallions): Use closer spacing and pull when plants are about finger-thickness.
Cultivate or mulch to control weeds and supply plenty of water during the growing season.
Harvesting and storage:
When about three-quarters of the tops have fallen over, bend over those still standing to hasten drying. After all tops are yellow, pull up plants and allow to dry in the sun for a few days. Spread out in a well-ventilated place until tops are thoroughly dry ( 2 to 3 weeks). Braid tops together, or cut the tops off 1-2" above the bulbs and store in a dry, cool, airy place.