I'm not sure what kind you want but will post a few
http://quilting.about.com/od/blockofthemonth/ss/christmas_tree.htm
http://blockcentral.com/freequiltpatterns.shtml
http://www.winnowing.com/patterns.html
http://www.getcreativeshow.com/seminars/pinetree_quilt.htm
http://www.equilters.com/library/PFP/GH-part4-bonsai-house.html
http://www.quilterscache.com/QuiltBlocksGalore15.html
http://www.quiltingassistant.com/pinetree.html
Ah so many trees so little time, I found so many I like. I am sure you had a certain kind in mind, I hope there is something you like :P
http://www.ezquilt.com/patterns/winterpinewall/winterpinewall.htm