Lots of strains of cannabis can handle a pretty strong frost. I've had plants handle frosts as low as 28 degrees F without killing the plant.
Things to consider, some strains are more sensitive to frost than others, if they are in pots this can make them more sensitive.
Sativa strains tend to be more sensitive to frost than Indicas. Indicas and Indica dominant hybrids are capable of handling frosts as low as 28F. but there have been reports of sativas handling frosts just as well.
I'll leave this sticky open to discussion for other experienced users to post their experiences, I will compile it into this. I felt this was needed as this question gets asked a lot when a frost comes by.
you can protect the plants if they are of manageable size or if you are handy enough to build a sturdy setup.
this can be as basic as a pvc greenhouse with plastic wrapped around, or even sheets if properly secured to not touch the plants... or as large as a full car port with greenhouse grade plastic secured.
how much the temperature rises the next day also tends to define how the plant deals with the frost. if it frosts and it rises up to 65 degrees+ with sun in the daytime, the plant is much more likely to take the frost and keep growing vs a plant that takes a hard frost and sees a 45 degree day with clouds....
cooler temperatures (55-40 degrees F) will definitely bring out some purpling in some strains, and cause flowering to speed up, nights that dip into the 35F zone boost this even more, bringing out even more color.
sorry for the organization of this thread, guess I'm too much of a stoner after all
this is my 2019 run. Sept18 it frosted hard enough to kill all my squash. Here is the morning of the 19th frozen before harvest, and a bud shot up close showing the trich coat. This was still super sticky dank after this freeze eventNot an outdoor grower but a basic question as knowledge is good....I know the plant will die if frozen of course, but if you were right at harvest and the plants froze, would it affect a ready to harvest result?
Huge sympathy and support from me to those dealing with outdoor environments. You folks still grow the best sxxx imo when done right! Sun