I put in around Thanksgiving, because I put up our trees the Friday or Saturday after. (Pity those without Thanksgiving! How do they know when to put the tree up? And, wait, what about the Canadians? Have theirs been up since October?)
We have 4 Christmas trees. And only 1 is green. And my poor husband is Jewish.
True about the fresh cut.
In Colorado, we sometimes would go up into the designated cutting area with neighbors. One year, our neighbor’s tree not only did not die, it began putting out fresh new green growth! It just kept going and going. They regretfully put it in the alley, rootless but growing, after Valentine’s Day.
We put up the tree not long after Thanksgiving. We’ve been doing a potted tree that stays outside the rest of the year.
One year I kept a tree fresh until well after Christmas. I decided to keep it up as an experiment to see how long it was going to stay fresh. At the end of February it was growing next years new growth. I threw it out at the beginning of March having proved cutting a tree doesn’t kill it for your long holiday house occupation. The only ones I cut that dropped the needles badly were ones that got a sharp cold spell before I could cut the tree. The tree’s in lot’s have gone for weeks without water and been stressed in adverse conditions. Those are your problem trees.
I love decorating. I have a fake tree; needles are too much trouble, but I usually put it up every year around Christmas. Generally I keep it until the day after we get back from downstate, but now I’m thinking I should keep it for all 12 days. Thanks, my SO is going to love this. 
Maybe after the Messiah comes?
Did the tree rustle “Brains?” Or maybe “Roots?”
We got fresh cut trees in NJ, but places to cut them are too far away here in the Bay Area.
After the 1st of Kislev (new moon before Hanukkah, 25 days before Hanukkah) or after Thanksgiving, whichever is later. The menorahs come down sometime after Christmas when I get around to it. The menorahs (I usually do 4 or so, I like menorahs and they are not much work) and an electric menorah or two are all I do in terms of decorating, so putting up and taking down the decorations isn’t too hard. The menorahs with candles are all in the living room, since we can’t leave lit candles unattended because of the cats.
My parents put up their tree on December 4th, which is my brother’s birthday. It becomes a bit of a family get-together with many munchies and drinks and amiable bickering over the correct way to do things. I’ve more or less adopted the same tradish in my own place, despite my brother and parents being in the next province over.
3-4 weeks, usually the weekend after Thanksgiving, but sometimes the week after that. This year, we won’t be in town so it won’t get done until the first weekend in December.
I like decorating for Christmas, I put out a lot of other things in addition to just the tree, so I like having it around to look at for a few weeks.
It goes up a week to 10 days before Christmas, and it comes down the first possible weekend after Jan 1. If it went up any earlier or came down any later, I’d really be sick of it. It’s pushing 3 weeks as it is, which is just about the limit.