Traditionally, most folks in the Midwestern States would
wait until at least mid March before risking any seedlings or plants that could
be killed by frost. Better still, Zone 6 people were advised to hold back until
the first week of April as a late frost could still occur. I’ve always tended
to follow that plan with the exception of onion
starts which can be placed out just as soon as the soil can be worked. These
cold hardy plants benefit from early plantings in good rich soil so they can be
the best they can be by summer time.
I’ve already begun to keep an eye out at my local grocery
stores for those bins filled with red, white and yellow onions, so that I can
have them on hand during the next brief warm up outside. Last year in 2012, I
saw them out in the first week of February and wrote a post
on it. Those guys turned out really well and I enjoyed harvesting some as
scallions as early as April of that year.