First lady Michelle Obama has kicked off the holiday season at the White House by welcoming this year's Christmas tree. 

It's a Fraser fir grown in Pennsylvania that stands more than 18 feet tall. 

The tree is traditionally displayed in the Blue Room of the White House. The first lady says this year's tree will honor the military. 

Two days after President Barack Obama pardoned "Abe" and an alternate turkey named "Honest," the transition to Christmas was in full throttle Friday at the White House. Workers were busy putting up an array of Christmas trees inside the grounds, while the Blue Room centerpiece arrived via horse-drawn carriage. 

The White House Historical Association credits Lou Henry Hoover with establishing the custom of decorating an official tree in the White House.