It doesn't need to get down to zero, unfortunately. If it's cold enough for frost, it's too cold for most varieties of cannabis. I don't know of any strains that could survive freezing temperatures. Reason being, cannabis is like 80% water. Once the temperature drops down to freezing, it does irreparable damage to the cells of the plants. This is why most perennials go dormant during winter, and don't produce any new foliage until the spring.
Mr. Clandestine Reviewed by Mr. Clandestine on . Winter Grow? Is it possible to grow a northern strain in a southern winter? Rating: 5