From Arlington County:
Christmas Tree Collection will be from January 3-17, 2012 on your regular refuse day. Since trees will be ground into wood mulch, please remove the tree stand, lights, and decorations. Please do not place the tree in a plastic bag.
During the first two full weeks in January, Christmas trees are collected curbside for residents with curbside refuse and recycling service. Residents are reminded to place the tree on the curb no later than 6 am on your regular trash collection day and to remove all decorations, nails, stands, and plastic bags. After the trees are collected, they will be ground into wood mulch for garden use. Special unbundled brush or metal pickups will be suspended during this time.