How low can the temperature go without harming my coleus/geraniums outside (that I plan to overwinter)? The past years I took them inside when the temperature barely got cold, which seemed too early. Next week the low temperature is going to be 40 degrees F. I know freezing is immediate kill, so I definitely am not going to wait that long. But a few degrees above freezing may still hurt the plants? Should I take them inside this weekend? Thanks!