How Do Christmas Trees Get Their Shape?

Santa among Christmas trees — Christmas trees don't magically, or genetically, aspire to a perfectly peaked shape but rather take six to eight years of careful pruning. Andreas Rentz/Getty Images

During the final month of the year — and often, much sooner — vast numbers of harvested trees begin their migration indoors, where they are festooned with ribbon, garland, ornaments and lights.

Although these trees are grown in the spirit of Christmas, they don't magically, or genetically, aspire to a perfectly peaked shape. "Once the trees reach about 3 to 4 feet (1 to 1.2 meters) in height, we begin a process called 'shearing,'" said Ben Butler, farm and finance manager of Butler's Orchard in Germantown, Maryland, in an interview with the American Farm Bureau Foundation for Agriculture. "After the trees grow in the spring and their new growth begins to harden off, our crews go through the trees one at a time and help guide the shape of the tree using a very long and sharp knife."

The most common types of Christmas trees are Douglas fir, Canaan fir, Fraser fir and several species of spruce or pine. However, out of the 630 species of conifers in the world, the majority don't actually grow in a strictly triangular shape, so trimming is a crucial task when growing those specimens meant to become Christmas trees. This pruning process must continue every summer until the trees reach a marketable age, which usually takes six to eight years.

Have a look at the tree shearing process in this video from Glove Hollow Christmas Tree Farm in Plymouth, New Hampshire:

Historical Tradition

So why do Christmas celebrants demand pyramidal trees during the holidays? The notions behind much of the world's traditional Christmas décor originated in northern Europe, particularly Germany, where enduring images and tales from the mid-19th century still ensure sugarplums are dancing through our heads and that our Christmas trees are conical.

In that part of the world, evergreen trees are pyramid-shaped for good reason: Each needle-leaf layer has a better opportunity to gather sunlight for photosynthesis if the sun isn't blocked by wide top layers. This tiered arrangement allows the trees to shake off heavy snowfall, and the wide spaces between branches let the winds whip through without causing massive damage.

Although synthetic Christmas trees don't generally drop needles on the floor or pose a fire danger by drying out, they can't replicate the experience of selecting a real Christmas tree. And for a lot of people, it just isn't Christmas without the piney smell of a freshly cut tree.

Still, industry data for 2019 said that 82 percent of Americans put up a fake Christmas tree, while only 18 percent put up a real one. But maybe more people should go for the real thing. Real Christmas trees provide homes for wild birds and animals, while storing carbon and generating oxygen. And, best of all, the trees are a renewable resource – when one is cut, a new one is planted in its place.