I live in New England. My GH is also on the north side of my home. It receives
no direct sun during Nov, Dec, and Jan. I have two temp zones, and maintain a
min nite temp of 46F in one, and 60F in the other one. I heat to keep the min
temp at night, and a min temp of 10F higher during the day. Rarely does the
temp go higher than the set temp on the thermostat. I have always stressed that
light is the most important factor in flower production, and to make up for my
decreased light, due to area, and location, I use high output lights for
supplemental lighting the entire year, in both zones. I grow 155 genera, and
although all of us can always do better, I seem to have done fairly well with
this set up.