When you think of Christmas, you probably think of a Christmas tree. In fact, the Christmas tree is one of the most recognizable images of the season. Almost everywhere you go, it's the focal point of people's holiday decoration. You adorn your tree with ornaments. You pile your gifts under it. And you gather around your tree to sing Christmas carols and drink eggnog.

Christmas Tree Image Gallery

An 18-foot-tall tree is delivered to the White House
Luke Frazza/AFP/Getty Images
An 18-foot-tall tree is delivered to the White House. See Christmas tree images.
The growing and selling of fresh Christmas trees is big business. According to the National Christmas Tree Association (NCTA), the industry supports about 21,000 tree growers and employs more than 100,000 people in the United States [source: NCTA].

Video Gallery: Holiday Energy-saving Tip
If half of all traditional Christmas bulbs were replaced with LED bulbs, it could yield savings of $17 billion a year in energy bills. Learn why LED bulbs work so well for Christmas lights in this news video from Medialink.

­But how do you choose a pretty tree, and how do you keep it from drying out and turning into a fire hazard during the holidays? In this article, you will find out everything from how and where the trees are grown to how to select and care for your tree through the holiday season.

O Tannenbaum!
Just one acre of Christmas trees can produce enough oxygen for 18 people [source: NCTA].