Every night here in Calif foothills, we hit the low 30s and often high 20s around 4 (we have three thermometers at different places in the garden). But the sun is on them at around 8.
We did cover them during the last cold front, but last night, the outside was warmer than inside our ghetto tent.
The ladies are all purple, except for one strain and they are not blinking with these temps.
They're ok unless the day temps and sun don't respond high. Don't go cuttin' shit unless shit is cold all day with no sun and 20s at night.