Onions come in
Onions come in long-daylength, medium-daylength, and short-daylength varieties, based on amount of sunlight needed. You grow long-daylength in northern latitudes and medium-daylength in central latitudes. In the southern latitudes, you need to plant short-day onions. Short-day do not come in sets. You need to seed OR plant bareroot transplants from local nurseries.