(Q)Should I add bleach, aspirin, fertilizer or other things to the water to make trees last longer?

(A)No! Research has shown that plain tap water is needed. Some commercial additives and home concoctions can actually be detrimental to a tree’s moisture retention and increase needle loss. Water holding stands that are kept filled with plain water will extend the freshness of trees for weeks.

Behnkes’ Larry Hurley says:
Additives like Prolong are intended to keep the pores of the tree open so that it continues taking up water, by suppressing the growth of bacteria in the water. This is important in fresh cut flowers; however, the Christmas tree folks say it is not necessary. I don’t know what is in Prolong. Some years I have used Prolong, some just tap water.

The prime keys are:

1) Start with a fresh tree, and a species known for good need retention eg Fraser Fir or Noble Fir. I personally have found over the years that Balsam fir and Douglasfir bought from a tree lot drop needles quickly and have a short useful life as a cut tree relative to Fraser or Noble. We are not carrying Balsam or Dougfir this year.

2) A fresh cut off the bottom of the trunk when you get the tree (we do that for you) because the end of the trunk dries out and it will be unable to draw water: there is an air block similar to an air block in a radiator–water can’t go up the trunk because air is blocking contact between water in the stand and water in the trunk. It’s like trying to suck soda through a straw with a hole in the side of the straw–lots of air, not much soda. It has to be a fresh cut to draw water out of the reservoir. As they say, get in it water as soon as possible; if not within 5 to 8 hours of a fresh cut, then you must re-cut the stem. And don’t let the tree go dry in the tree stand.