1 Pain that does not diminish with rest, and pain that may be worse at night than during the day. 2  Back pain along with constitutional symptoms, such as loss of appetite, unplanned weight loss, nausea, vomiting, or fever, chills or shakes.
Unstable chemicals. Onions produce the chemical irritant known as syn-propanethial-S-oxide. It stimulates the eyes' lachrymal glands so they release tears. Scientists used to blame the enzyme allinase for the instability of substances in a cut onion.
If you want to harvest all your onions at the same time you can push down the tops of the slower onions yourself so they are all on the same âschedule.â I like to wait until they all flop over themselves, but it is definitely up to you.hey will let you know they are ready to harvest as soon as the tops flop. I love this about onions because it keeps the guesswork to a minimum. 2 Harvesting. After your onions have flopped over and they have had the chance to dry out for a week or two, itâs time to get out there and start pulling them out. 3 Curing.