QUESTION: I’m planting onions, but I am only that far with learning how to grow them. How do you pick and store onions? -Kim T
ANSWER: Onions can be harvested whenever they reach a usable size. However, if you are harvesting them to put away to store, wait to start the harvesting process until the leaves begin to fall over or turn brown at the edges. After a week in this condition, carefully dig your onions out of the ground using a fork. Dry harvested bulbs in the sun for a another week. Try laying them on the soil surface, or on a wire rack for better ventilation. If the weather is wet, move them under cover, such as a tunnel or a greenhouse instead. Be careful handling mature onions to prevent bruising.
After your onions have dried in the sun for a week, continue the drying process, called curing. Moving them under cover and allow the outer skins to dry out completely. Onions can be dried on racks or on layers of newspaper inside of a greenhouse, hoop house, or cold frame. This also works for curing and drying out other alliums such as shallots and garlic. Spread the bulbs out as much as possible and make sure that there is good air circulation in order to wick away moisture and prevent mold or rotting. The onions could take up to two further weeks to fully dry out. When the skin becomes papery, onions are ready for storage. The leaves will shrivel up completely, and the roots become wiry and dry.
Once your onions are ready for storage, cut off the roots and remove any loose skin. If you want to store your onions by braiding your bulbs together, cut the stems to within two or three inches of the neck of the bulb. If you don’t want to braid them for storage, cut the stems to the neck.
Store onions in a dry, cool, well-ventilated location that is preferably dark, but at the very least, out of the reach of direct sunlight. An unheated room of the house is ideal, such as the garage or the basement. Use thick-necked onions and soft bulbs first, as these will not last long in storage. Individual onions can be placed carefully into net bags. Either purchase vegetable storage nets, or re-use netted bags that originally held oranges or other citrus fruit, for example. These bags should be hung so that the bottom of the bag doesn’t touch the ground. Check the bags periodically and remove any onions that have gone bad.
Another practical and ornate way to store onions are on onion strings. To make one, cut a length of string to about three or four feet and tie the two ends together, forming a loop. Hang the looped string from a hook and begin braiding your onions onto the string. Insert the first onion through the loop and bend the stem around the back of the string, returning it through the loop. To anchor the onion into position, push it down to the bottom of the loop. Then, begin working in additional onions using the same technique, placing the stem through the loop and then weave it around the back of the string, bringing it back through the loop, pushing it down snugly to rest against the previously braided onion. Rotate additional onions so that they sit neatly in a spiral shape. When finished, hang your completed onion braid in a cool, dry, dark location and enjoy the onions as needed, working your way down, taking onions from the top of the string instead of the bottom.