I'm gardening in zone 8a, where we've finally seen the end of high 90s temperatures about a week and a half ago. Right now, we're enjoying some low 80s during the day, with morning lows hitting around 60. My growing season is pretty short; the first frost often arrives around the end of November or early December. I've been experimenting with how early I can transplant brassicas and think I'm about ready to dig into that—early September seems to be the sweet spot. However, I really struggle because the heat and long dry spells make it tough, even with some shade cloth.
1 Answer
Broccoli and Brussels sprouts are surprisingly hardy and can tolerate temps as low as 28°F, as long as they’re not exposed for more than 4 hours. While I don’t grow cauliflower myself, I can say that both broccoli and Brussels will actually taste better after a few light frosts, as they get sweeter! I usually leave my broccoli in until mid-November and keep harvesting Brussels into January. If it’s going to be below 28°F overnight, I just cover my plants with a plastic sheet to keep them warm; I even used snow as insulation once! Plus, don't forget about winter lettuce—varieties like Landis and radicchio can handle the cold pretty well. Happy gardening!
I’m not too worried about low temps either since we don’t have deep freezes where I live. I'm just really focused on when to transplant my brussels sprouts and broccoli, given how hot and long our summers are.