Why Christmas Trees Smell So Good


When I was a teen, a French girl came to live with us for the summer. She caused quite a stir in our button-down  town with her skinny jeans, lace-up wedge espadrilles and oversized red glasses. That being said, what I remember most was her preference for a men’s cologne named Pino Sylvestre. Wherever she went, an intoxicating ‘green’ fragrance trailed in her wake.

A quick Google search today reveals that the original Pino Sylvestre was marketed as,

“A breath of fresh air in a bottle, uncomplicated and inviting.”

Launched in 1955 by Massimo Vidal, it comprised a mix of 12 essential oils gathered mainly from the forest. Today, Pino Sylvestre is produced by several companies, so I can no longer vouch for its authenticity. But I do recognize its distinctive, pinecone-shaped bottle, a vial that still evokes memories of a life more adventurous than my own.

Pino Sylvestre ad/mavive.com


Although it’s been ages since Pino Sylvestre occupied a place on my dresser, it continues to pop into my mind each year when I buy a Christmas tree. No sooner do I set eyes on all those conifers and I’m whisked back in time by that fresh piney smell. As it hovers above the trees, you could swear they were breathing.

For many people, the smell of pine, fir and spruce is inextricably linked to the holidays. In my case, it also reminds me of my younger self and of life on the wilder side. Most people, though, would agree that the earthy aroma just makes them feel happy.

This is not, however, the reason why the trees produce it.


So what is the secret behind that piney, Christmas tree smell? It’s tied up in resin. Woody plants such as pine, spruce and fir all produce the sticky, viscous stuff. Resin protects a tree by acting as a kind of deterrent. Not only does it ward off pests and diseases, but it also functions as a bandaid. When a tree is injured, resin oozes out and seals off the wound.

Amber-colored resin

While most trees produce resin in response to injury, some also produce it spontaneously from branches and cones. In fact, resin can be found all over the tree — in the trunk, twigs, cones and even the needles. First appearing as clear, it gradually yellows as it ages. Soft woods like conifers (aka Christmas trees) have more resin than hardwood. And pines have the most.

Pine cones leaking resin

In its hard, fossilized form, resin is known as amber. Because resin often leaks out without warning, many ancient flowers and insects have ended up encased in amber, providing an interesting window into previously unknown species.

Amber is fossilized resin


So why do Christmas trees smell so outdoors-y? The answer is terpenes.  A primary constituent of resin, these organic compounds perfume our forests while providing antimicrobial properties that allow trees to fight fungus and disease. Ever notice how fragrant a pine forest is in summer? In warm weather, higher amounts of terpenes are released by trees as a natural form of cloud-seeding. This allows them to cool the forest while controlling their atmosphere.

Terpenes help forests regulate their atmosphere

Different pine species have different terpene content, which in turn has an effect on their smell. The resin of the North American pine, for example, shares a terpene with plants in the parsley family. (For this reason, it is said to have a grassy fragrance.) Ponderosa pines, on the other hand, have a sweet-smelling terpene that is also a major component of turpentine. 

Because of their various aromatic and healing properties, terpenes have been used for ages in perfumes and aromatherapies as well as medicines and cleaning products. You may have noticed pine trees that have part of their bark stripped away and a series of deep V’s cut in their trunks. These trees are being tapped for resin. When done properly, conifers can be tapped for up to 20 years or more without hurting the tree.

Trees being tapped for resin


I learned later that Pino Sylvestre most likely got its name from the Latin, Pinus sylvestris, commonly known as Scotch Pine. Scotch Pines are the most widely distributed pine in the world. Their excellent needle retention and bright green color has made them the most common Christmas tree in the US for decades. Today, they account for approximately 30 percent of the 35 million Christmas trees harvested annually.

While some characterize its scent as ‘dry-balsamic’, Scotch pine is generally described as herb-y, fresh and slightly grassy. For me, however, it will always be the essence of that Christmas tree smell, the great outdoors and a certain men’s cologne called Pino Sylvestre.