Freeze Hardiness of Onion Xplants

Well I am running behind in my garden planting this year, and have not transplanted the onions and leeks from the GH to the garden. Typically I would have done so at the end of April in my area. I have time and their bed is prepared now but I am a bit concerned that the weather forecast is predicting near freezing temps for Mon and Tues next week, and we typically are a few degrees cooler so maybe 28F. If it were earlier, I’d just wait, but these plants are getting pretty big for the GH (much bigger than a pencil which when I like to move them out).

So I am wondering which is the better path, transplant now and hope a couple of cold nights don’t set things back too much, or wait and hope transplanting larger plants isn’t worse than the freeze. Either way will likely work, I’d just like to take the best course.

Any thoughts from the onion experts?

My concern with transplanting now then having the cold is they may bolt quick. I would wait until after the freezes.

@mksmth good point, which I hadn’t thought about. In general, it’s supposed to take a week or so of cold then warm to induce bolting, but who knows what the future weather might be. And again transplant size is a big determiner of bolting (smaller than a pencil is recommended to reduce bolting), so waiting a week to transplant will hurt in that respect.

No obvious answers unfortunately…

I planted onions in April and the next night there was a freeze. The tiny plants were frozen like door nails. I thought it was the end of them. They survived though and they went through a couple of more freezes uncovered. They are nice growing onions now. But I would wait until the danger of freeze will pass, before planting there is no need to stress them if you can avoid it.

@Steve333 I plant dixondale transplants and mine went in mid February. We had days in the 70’s then days near freezing. I always plant the smallest in the bunch and plant larger ones in a group for green onions. Both the large ones and the small ones are bolting equally. Most of nine have sized up nicely though.

Thanks.

Well, in thinking about this some more, my typical schedule would have had me xplanting the onions outside almost 1 month ago. And typically the onions would still get some freezes and cold weather most years, but I don’t usually see more than 1-2% bolting.

I did visit Dixondale’s site and see their videos on onions. They seem to be concerned with temps < 45F for a long time (week or two). I wonder if their bolting advise may be geared more towards warmer climates. Because in my location, the outside onions in Apr and May will see night temps near freezing for almost all that time. So perhaps the onions never get enough warming to make them think it is summer. Just a thought, because based upon low temps alone, I should be seeing much higher bolting rates per Dixondale.

I could be wrong but I think now it may be more critical to transplant before these plants get any bigger and that the freezing is a lesser concern. Anyway, I will find out.

I appreciate the input, and will let folks know in the fall, how this worked out…

I believe for bolting you need a long cold exposure, more than 2 nights. And onion is very hardy plant.