According to the Consumer Product Safety Commision

According to the Consumer Product Safety Commission

"A Dry Christmas Tree burns faster than Newspaper."

Within five seconds of the dry tree catching fire, flames cover the entire tree before hitting the ceiling.

In a simulated trial: 

Keep candles far away Don't smoke near the Tree Use a stand you can fill with water

Some safety tips:

Make sure the needles are green Ensure they don't easily fall off The Trunk should be sticky to touch

If you buy a Real Tree

Artificial Christmas Trees are  safer, and will last years.