When it comes to your Christmas tree it’s not much different than a tree in your landscape…..it needs “re-hydration” when nature calls so to speak. Foliage or in this case needles transpire like people perspire when things warm up. In the case of an evergreen they’ll transpire indoors when you turn up the heat.
Due to a decrease in hydrostatic water pressure in the needles as they transpire the tree “pulls” water upward through the xylem to re-hydrate the tree. The same applies to trees and plants in your landscape. The big difference of course is that the Christmas tree in your living room has no roots to reach out.
You have to reach out and provide the water to your tree so the “FMC” does not drop to unacceptable levels at which point “yule” have to reach for a vacuum cleaner. FMC is Foliage Moisture Content. Make a fresh cut on the bottom of Christmas tree and immediately place it in water. When you get a wound your body begins to clot and scab the wound naturally. The tree does the same with sap at the cut which in turn inhibits or cuts off moisture flow through the tree.
When the “FMC” drops below 25% needles will drop and the tree may no longer draw water even though it is sitting in water. The greater the water pickup results in higher foliage moisture content which also provides the best ignition resistance.
Trees with a high “FMC” tend to self-extinguish versus a dry tree with low “FMC” can go up like a torch if subjected to an ignition source. Light up your holidays the right way and get long lasting fragrance and beauty from your tree by making a fresh cut, put the tree immediately in water and keep the water bowl full until you remove the tree after the holidays. Placing a fishing bobber or ping pong ball in the water will help you see at a glance the water level in the bowl. Pay attention to your tree’s “FMC” and it will make all your Christmas “Greens” come true!