Hardening off Temperatures for Brassica

[Maxy24]

I'm hoping to be able to get my Cabbage, Brussel Sprouts, and Broccoli into the ground in a week or two, so it's time to start hardening them off. I also want to get going with that because I'm running out of space under my lights in the basement. I only have two fluorescent light fixtures and now that I'm transplanting everything out of cells and into cups I'm running out of space fast.

However, it's pretty chilly all week. Low to mid 40's during the day and very cloudy with some rain. But next weekend it shoots up into the upper 50's. Should I wait until next weekend to start hardening them off or do you think they can handle the colder temps? I've never done brassicas properly, I've always done them on the same timeline as tomatoes (which is why I've never had any luck with them) so I'm not used to putting stuff out in the cold.

[fourfortytwo]

I'm further north than you, and without coastal warming, and we've had a hell of a winter, I was planning on transplanting them on the "50% chance of frost" day. `

[applestar]

40's and 50's are nothing to the brassicas especially the ones you've listed. It's the overnight low I'd be more concerned about. Left mine out in translucent storage tubs with lids down to hovering below freezing 28°F at dawn, as low as 30° through the night. Brought the cauliflower in when freezing temp was forecast, but have been leaving them out down to 34°F with windbreak/cover. Nappa Chinese cabbage is being more carefully coddled -- I'm treating them like celery and keeping them in the garage when below 50°F at night.

Broccoli can easily take temps down to mid 20's but not after they start to head up. Those flower buds are tender and can only handle light frost at best.