that wont work! if u want ur plants to survive during winter, ur gonna have to get a heat blanket, that u can get at a hydroponic store. u should dig ur plant up and put it under 24 hours of light until next grow season to ensure its survival. i know people who kept there plants alive during winter, but it wasnt easy, they had to take constant care of it to keep it alive. just cut off ur buds and regenerate it under 24 hours of light inside, marijuana plants dont do to well under intense cold! but it will make em turn purple!!!!!!