From this week’s e-mail file…
“Dear Dr. Cregg:
As I’ve done for many year, this year I harvested my “wild” Christmas tree from the Huron-Manistee National Forest. I cut the tree at ground level. Soon after I brought it home, it started sprouting new light green clumps of needles at the tips of many branches. Is the tree actually growing? It doesn’t seem possible that it’s still alive, but it seems to be thriving and I hate to toss the tree to the curb if it’s fighting for life. I am tempted to leave it in the tree stand to see what happens….”
The tree is dead, it just doesn’t know it yet. Depending of the species, some Christmas trees will break bud and begin to grow once they are brought indoors. The tree is still alive in the sense that its needles are still carrying out photosynthesis and water is still moving up the trunk to the needles. But since the tree has no roots and no way to produce any new roots, it has no prospect for long-term survival. The phenomenon you’re observing is common in some spruces and other conifers adapted to cold regions. Before you cut the tree, the buds were exposed to enough cold to meet their chilling requirement to overcome dormancy – the only thing that keeps trees in wild from growing at this point are cold temperatures. Once you brought it indoors, the tree ‘thought’ is was spring and started to grow. If you or a family member want to do a little science project you could keep the cut end in water and see how long the tree lasts. Eventually, however, the conducting elements at the cut end will begin to plug with resins and the tree won’t be able to move enough water to meet its needs and will expire.