Question: I’ve been told that if I knock over the tops of my onions, they will be ready to harvest earlier. Is this true?
Answer: Bending over or breaking the tops of onions will indeed result in an earlier harvest, but at the expense of bulb size. The longer the onion tops remain green and healthy, the larger the resulting onion. Therefore, you should wait until at least half of your onion tops have fallen over naturally and begun to yellow before harvesting. At that point, you can gently lift all the bulbs with a spading fork and lay them out to dry on the surface of the ground. If rain threatens, move them to a well-ventilated garage or other dry location.
For long-term storage, the skins must be allowed to become fully dry and papery–which may take two or three weeks. The roots and the dried tops can then be trimmed off and the bulbs can be stored in mesh bags or shallow boxes in a cool, dry, well-ventilated location.