The ‘king of the forests’ who, through winter, ‘keeps his adornment’, is each year promoted to monarch of our homes on the evening of December 24th. But it is only after years of slow growth that it acquires its letters of nobility in our living rooms where, dressed in luminous garlands and sparkling balls, it arouses the wonder of young and old alike. Then, once the holidays are over, it is stripped naked and tossed unceremoniously on the sidewalk, where it will be collected and recycled. Here is the story of the discreet, then royal, and finally fallen life of the Christmas tree.
Most fir trees that achieve Christmas tree status were grown in the Eastern Townships or in the Chaudière-Appalaches region. But before being planted in old pastures in these two regions, the saplings first hatched in the nursery from seeds that growers harvested in the fall from the cones that sprouted during the summer.
Small fir trees between one and two years old are then placed in the ground, preferably in “slightly sandy and acidic soils, moist, but well drained”, specifies agronomist David Wees, lecturer in horticulture at the Macdonald campus of McGill University.
“Cultivated fir trees grow faster [que leurs congénères naturels] because, in the early years, you do weeding to eliminate competition, says Wees. The fir trees that grow naturally in the forest are for their part in competition with all their neighbours, and they often develop in partially shaded areas, whereas in the fields where fir trees are grown, there are only fir trees whose conical shape does not cast a shadow on neighbors. »
In addition, “the cultivated trees are pruned regularly, each branch that protrudes too much is cut to obtain a perfect cone shape”.
Cultivated fir trees take eight to ten years to reach the height of 2 to 2.4 meters, at which growers usually cut them for Christmas. “But if there are more heat waves and drought during the summer due to climate change, this stress could slow tree growth, because the fir tree needs a good amount of water to grow at a rapid rate. normal,” warns Wees.
Mainly two species are grown in Quebec for Christmas trees: balsam fir and Fraser fir. The balsam fir, which bears the scientific name ofAbies balsamea, is a native species of Quebec and hardy, that is to say that it resists very well to extreme cold. It is found in the boreal forest to James Bay. The Fraser fir (Abies fraseri) is a species that grows naturally in the United States, especially at higher elevations at the top of the Appalachian mountain range in Virginia, Tennessee, and North Carolina.
But how do you recognize balsam fir from Fraser fir, or even spruce, or spruce, which is also a conifer with persistent narrow needles that could very well serve as a Christmas tree?
If we cut the spruce needles in the direction of width, we will see that they are square while those of all fir trees are flat, which explains the fact that we can roll the spruce needles between the thumb and the index whereas one cannot it with those of the fir tree. Additionally, spruce needles are sharp, prickly and somewhat stiff while fir needles are more flexible and rounded at the tip.
Fraser fir is distinguished from balsam fir by the bluish color of the underside of its needles. But above all by the fact that it smells almost nothing unlike balsam fir. However, it keeps its freshness longer than balsam fir, hence the marked interest of American producers for this species.
Fraser firs keep longer once cut, probably because their needles are a bit more waxy, which slows their drying out, Wees says.
The fragrance of balsam fir
The balsam fir may lose its needles sooner, but its unique fragrance fills the living room and thus contributes to the magic of the Holidays. The fragrance of balsam fir results mainly from the presence of three compounds from the terpene family: alpha-pinene, beta-pinene and bornyl acetate.
Alpha-pinene and its isomer, beta-pinene, are very odorous molecules that volatilize and diffuse into the air more easily at a temperature of 20°C, that of our homes, than at 0°C. , that of the outside, where they remain in liquid form. Since alpha-pinene is one of the main constituents of turpentine, which is extracted from softwoods, such as fir trees, its fragrance is very similar to that of this essential oil. Beta-pinene, on the other hand, exudes “a fresh and woody note”. Bornyl acetate, for its part, emits a slightly camphorated odor. In addition to these three substances, other odorous molecules contribute to the fragrance of the Christmas tree, in particular limonene (smell of citrus fruits), myrcene (smell of thyme, hops), camphene (smell of camphor), alpha -phellandrene (smell of mint) and delta-octalacton (smell of coconut).
The intensity of the fragrance given off by the needles of a fir tree depends not only on the ambient temperature, but also on the level of hydration of the fir tree. In this regard, Mr. Wees recalls the importance of keeping the base of the trunk of our Christmas tree in water. “Even a month after being cut, the tree is still alive. And a healthy tree can absorb up to a liter of water per day in a house. A tree that drinks less is a sign that it is in poorer condition. This water replaces that which is transpired by the needles. As long as the needles are present, the water will evaporate through the phenomenon of transpiration. And the warmer the house, the higher the sweat rate will be,” says Wees.
Once the holidays were over, having now lost its aura, the withered tree was taken out of the house and left on the sidewalk like a beggar waiting for City employees to pick it up.
The City of Montreal collects Christmas trees, which it sends to two wood recycling sites, where they are reduced to chips to be recycled or used for energy recovery.
“Energy recovery is the use of recovered materials in an energy production process by combustion. Thus, the wood crushed into chips is transported to companies that burn it for energy purposes. This material is mainly used as biomass for the production of electrical energy or heat”, specifies by email the media manager of the City of Montreal, Kim Nantais, before specifying that to know the Christmas tree collection schedules, citizens can consult the Info-collectes application on the Ville de Montréal website.
But it is possible to dispose of your natural Christmas tree in an even more ecological way. “If you have enough space on your yard, let the holiday tree serve as a birdhouse. This is the most environmentally friendly option,” suggests the City of Montreal.
This is how the lavish life of the Christmas tree ends.