We planted sweet onions for the first time this year and they seem to be doing fine. How do I know when it is time to harvest them? I can see that they are about the size of a baseball, and they have thrown up shoots that I think will turn into flowers.
Do I let them continue to grow until I need them or should they be harvested at a particular time?
Also, once they are harvested how should they be stored until we need them?
It’s been a while since I’ve grown onions, but I recall that you should harvest before they put up flowers. Something about the flowers eating up the bulbs.
I’ve grown onions for a few years with absolutely no idea what I’m doing, but they seem to reach their full growth around the time the tops start to flop over – we pick them as needed after that. (“As needed” actually meaning a weak or so before they’ll be needed, since we lop off the tops and let them dry for a week or two before we eat them. I have no idea what the “rules” are on that part, either.) We don’t plant all that many, so if there’s a drop dead date for harvest I have no idea what it might be.
Sweet onions have thinner skin and higher water content than regular onions - this means that they don’t store as well. So my WAG is that if you can** just harvest what you need as you need it. “Baseball-sized” seems plenty big enough to me.
Looks like you’ll find everything you need to know here.
Excerpt:
** i.e. if harvesting this one won’t disturb that one next to it