From KarmaBrooklyn:
Buy a Christmas tree from Tom Foley and help a local school financially. Tom, a former stock broker,sells trees at the corner of 8th Avenue and 8th Street in Park Slope. Tell Tom you would like $10 of the purchase price donated to P.S. 154 or P.S. 230 (choose which school's PTA you want the money to be given to), and then sign the school signature sheet.
Suggest to your family and friends that they buy from Tom too so that their tree purchase also helpsa school. It isn't necessary to have a child in P.S. 154 or P.S. 230 to have the donation made.
Delivery and tree set-up are free of charge if you already have your tree stand in place.
From "Finding the Perfect Christmas Tree: A Bluegreen Timeshares Holiday Exclusive":
Common Christmas tree varietals include the Douglas fir, the Canadian balsam, the Noble fir, and the Fraser fir. Tom Foley, the proprietor of a popular Christmas tree lot in Brooklyn, New York, recommends that shoppers seek out a Fraser fir if possible. He prefers Frasers for a number of reasons, namely because the varietal boasts approximately 30 branches and gives off an especially piney scent.