Good for you that your onions are doing well. As soon as the foliage begins to yellow (about three and a half months after young sets go into the ground), bend the stems so they are almost horizontal but don't dig up the bulbs yet. This will stop the growth and allow the onions to ripen. Pull away the soil so that the tops or shoulders of the onion are exposed. Lift the onions from the soil when the leaves turn brown. To make them keep longer cut the greens to within one inch from the top after you harvest. Spread the freshly dug onions out in the sun for a week or longer (do not let them get wet - a tray that can be moved indoors is best) so that the bulbs are allowed to become dry. Now they will store for months. The shallots and green onions can be harvested as soon as they reach the size you prefer. The smaller bunching onions do not keep well so harvest as needed and allow the rest to remain in the soil even during the winter. You can cover them with hay to extend the harvest but once the ground freezes they are done. If you harvest smaller onion bulbs that are less than 2 inches in diameter you can braid the tops together and hang them in bunches in a dry. Keep growing, Marianne Binetti