These very hardy perennials never form bulbs like storage onions do, but instead make delicious scallions.
How to plant:
Topsetting onions are the easiest kind of scallions to grow. Where winters are mild to moderate, you can begin harvesting very early scallions late in the summer of the first year you grow them. Start bulb-lets in the fall.
Plant one 1 deep, 6-10 inches apart. Where winter is severe, store the bulb-lets over the winter and plant them in early spring. After a patch is established, to increase the size of your planting there are several options. Easiest: you can let nature take its course, allowing the plant to “walk.” This happens when the weight of the maturing bulb-lets causes a stalk to fall over, resting the bulb-lets on the ground where they’ll self-sow.
Another way to propagate them is to divide the root clumps in early spring. And of course, you can intentionally plant some of the bulb-lets that form in your garden.
Cut stalks whenever you want green onions. They’re so delicious you have to take care not to over-pick the patch. The bulb-lets grown are like little nuts and have a spicy flavor that is improved by pickling.
Maintaining the patch:
Keep free of weeds. If you want to prevent the patch from spreading and want the largest supply of scallions, snap off the bulb-lets as they form. If you want to harvest the bulb-lets, stake and tie the stems so they don’t fall over and withhold water from the patch while the bulb-lets are maturing. Once a year, mulch the patch with finished compost to keep it growing well, or in spring dig up the root clumps and divide them.