Adding some sugar or corn syrup to the water in your Christmas tree's stand can help it stay fresh longer. The sugar provides nutrients for the tree, while the corn syrup helps to reduce water loss through the tree's needles. Additionally, adding a few drops of bleach or a Christmas tree preservative can help prevent the growth of bacteria and fungi, which can lead to browning and needle drop. Finally, making sure your tree has enough water and keeping it away from heat sources like radiators or fireplaces can also help extend its life.