We kept our office poinsettia in a south-facing window w/street lights, watered almost every day, never trimmed it. Pretty much everything that you could do wrong, we did wrong. Silly thing is now about 2' tall and has the red leaves all over the place. It's pretty scraggly on the bottom, but the top 10" has beautiful red leaves. Never got the total darkness (street lights), was kept at about 70degs during the spring, was fried in the summer (we don't turn on the AC in the summer on weekends, no one is here)... etc. In the winter, office gets down into the 50s at night (no heat is on.. why heat up an empty office?). Not bad for a $4 poinsettia!
