Hi Phillip
I keep my greenhouse at 60f. That's because I'm doing cuttings all the time, and over wintering new seedlings, plus other tender plants. The person who just wants to over winter their stock plants only need to keep it a 40f. This should be sufficient to keep them in the green. Just keep a check on them, and don't let them dry out, but again don't keep them too wet. It might sound stupid but I say keep them a dry moist. Does that make sense?
