Here are some tips on how to keep your Christmas tree fresh this holiday season. 1. Get the tree in water ASAP. 2. Trim the trunk: Make a perpendicular, half-inch cut to the bottom of a tree right before you place it in water. 3. Water, water, water: Check the stand daily to make sure your tree is getting all the water it needs. 4. Be cautious of heat sources. 5. Turn off the lights when you leave the room: Real trees can catch fire so make sure to check that all bulbs are in good condition and that the cords are not worn or frayed.