[Mick] For right now, it will be fine to plant them 3 inches apart in all directions (so you can plant 16 per square foot). And yes, you’ll leave them in the ground until maybe mid-October or early November (you want it cool to cold outside, but well before the ground will be at risk of freezing solid). Then you’ll dig them up, separate any that have formed multiple bulbs, and then plant them about 6 to 8 inches apart in all directions (so, about 4 plants per square foot). You mulch them heavily once you plant them in the fall. In the early spring, remove the mulch once you have onion leaves a couple of inches tall. Keep them weeded. In the heat of summer, the plants will flower (you can harvest the flowers and then use them fresh or dry them for winter use… they have a very strong onion flavor). The leaves will then die and the plants will go dormant until it cools off in the fall. If you want to harvest any onions to store and eat over the winter, then you harvest and cure them when they are in the dormant stage. But if you want to again use all of the onions in order to keep expanding your planting, then you can leave them in the ground and then harvest/replant them in the fall, as described above. Lastly, these onions are called Yellow Multiplier Onions or Yellow Potato Onions.