I don't think high twenties will hurt them if they're established in the ground by the time the weather hits. Broccoli is pretty hardy. A couple of years ago, I put some out early and we got a cold snap into the teens. I thought all the seedlings were toast and bought replacements, but most of them recovered. I had a lot of broccoli that year.

Well, ltilton, the whole "established in the ground by the time the weather hits" is exactly my concern. I'd planned to transplant them this weekend, but now it's Sunday, and the temps on Monday and Tuesday nights are supposed to drop into the high 20s.

So, do I plant them today, or wait until Wednesday or later?

My green goliaths survived being snowed on, crushed by ice and at least 10 degree temps.

I think it depends on the size of the plant. Do a search on broccoli buttoning (or go old-school and read about it in a book). Or maybe buttoning is solely temperature related. I forget. But buttoning means the plants survives but you get tiny little heads formed. How long is your cold spell supposed to last?

Why subject your nice broccoli seedlings to any extra stress when you can wait a few days and skip the drama? We had pea-size hail yesterday, and I was glad all my cabbage-ites were covered with cloches. This time of year, the weather is seldom fair. Proceed with caution.

I just brought in all my seedlings from outside, including broccoli and and cabbages. My seedlings are very small though. We're suppose to be having "more typical" weather, with highs in the 50's and lows in the 20's.

I'd rather not take the chance of losing my babies.

Under those circumstances, I'd hold off, just in case.