Why Do People Put Up Mistletoe at Christmas?

Mistletoe is a parasitic plant.

It grows not from the ground, but from trees—including oak trees.

To the ancient Celts, who (as I established in an earlier article on the druidic mistletoe rite) had a fondness for oak trees, mistletoe was a sacred plant.

When winter came and the skeletal limbs of great oaks and other deciduous trees were left stark and barren, the mistletoe remained, verdant and vivacious.

To quote anthropologist Walter Evans-Wentz:

“The Celts may have viewed the mistletoe on the sacred oak as the seat of the tree’s life, because in the winter sleep of the leafless oak the mistletoe still maintains its own foliage and fruit, and like the heart of a sleeper continues pulsing with vitality. The mistletoe [was] thus regarded as the heart-centre of the divine spirit in the oak-tree.”

source: The Fairy-Faith in Celtic Countries (1911)

Or as historian J. A. MacCulloch puts it:

“The life of the tree was in the mistletoe, still alive in winter when the tree itself seemed to be dead. Such beliefs as this concerning the detachable soul or life survive in Märchen (folk tales).”

source: The Religion of the Ancient Celts (1911)

It is perhaps not surprising then, given the special status of mistletoe, that a druidic ceremony would develop around it, paving the way for our modern, Christmas kissing ritual.

Now, the reason why we put up or hang mistletoe, rather than stick it in a vase or centerpiece, is because of the plant’s aforementioned properties:

Mistletoe grows on trees—up in the air. ‘Tis not a ground-dwelling plant.

In addition to its evergreen-ness, the airborne-ness (those are words, right?) of the mistletoe likely contributed to its interpretation as a holy plant; a plant imbued with the soul of its host tree. For the mistletoe, given its clinginess, can be said to hover between “heaven” and “earth.” To quote Frazer:

“Primitive man might think that, like himself, the oak-spirit had sought to deposit his life in some safe place, and for this purpose had pitched on the mistletoe, which, being in a sense neither on earth nor in heaven, might be supposed to be fairly out of harm’s way… We can therefore understand why it has been a rule both of ancient and of modern folk-medicine that the mistletoe should not be allowed to touch the ground; were it to touch the ground, its healing virtue would be gone. This may be a survival of the old superstition that the plant in which the life of the sacred tree was concentrated should not be exposed to the risk incurred by contact with the earth.”

source: The Golden Bough (1890)

So, there you have it.

People hang mistletoe because folkloric tradition, passed down from generation to generation, has taught them that it is forbidden to let mistletoe touch the ground.

It would ruin the magic, as it were.

In his 1912 book Christmas In Ritual and Tradition, Christian and Pagan, author and folklorist Clement A. Miles gives an example of how this belief persisted into modern times:

“The sanctity of Christmas house-decorations in England is shown by the care taken in disposing of them when removed from the walls. In Shropshire, old-fashioned people never threw them away, for fear of misfortune, but either burnt them or gave them to the cows; it was very unlucky to let a piece fall to the ground.”

source: Christmas In Ritual and Tradition, Christian and Pagan (1912)

Now, for the second part of the question: Why did mistletoe become a popular Christmastime decoration?

There’s also a simple explanation here:

Mistletoe was traditionally collected during the solstices, Midsummer and Midwinter. As Frazer explains: 

“[T]he mistletoe is gathered either at Midsummer or Christmas—that is, at the summer and winter solstices—and, like fern-seed, it is supposed to possess the power of revealing treasures in the earth.”

source: The Golden Bough (1890)

Did you catch that bit about mistletoe being able to reveal treasures? (More on that in a future post.)

In addition to the ancient Celts collecting mistletoe during the winter solstice, there’s the symbolism of the aforementioned “evergreen-ness” of mistletoe to consider (i.e. life persisting in the starkness of winter).

What’s more, mistletoe doesn’t merely persist in winter, it thrives; it bears fruit, which also may have contributed to why the plant became associated with Midwinter. To quote Miles:

“Some further consideration may now be given to the subject of Christmas decorations in various lands. In winter, when all is brown and dead, the evergreens are manifestations of the abiding life within the plant-world, and they may well have been used as sacramental means of contact with the spirit of growth and fertility, threatened by the powers of blight. Particularly precious would be plants like the holly, the ivy, and the mistletoe, which actually bore fruit in the winter-time.”

source: Christmas In Ritual and Tradition, Christian and Pagan (1912)

Full disclosure: From a decorating perspective, mistletoe hasn’t always been associated strictly with Christmas. In some communities in England, for example, people would wait until New Year’s to bust out the mistletoe. As Miles explains: 

“The Shropshire custom was to leave the holly and ivy up until Candlemas, while the mistletoe-bough was carefully preserved until the time came for a new one next year. West Shropshire tradition, by the way, connects the mistletoe with the New Year rather than with Christmas; the bough ought not to be put up until New Year’s Eve.”

source: Christmas In Ritual and Tradition, Christian and Pagan (1912)

Even this tradition is likely to have a Celtic origin, however. For while the Celts were known to gather mistletoe on Midwinter, the Gaulish Celts would gift it to one another on New Year’s. To quote X. B. Saintine:

“The Gauls…dried [the mistletoe] carefully and put the dust into pretty little scent-bags, which they presented to each other as New Year’s Gifts on the first day of the year. Hence, in some provinces of France, the cry is still heard, ‘Aguilanneuf’ (au gui l’an neuf), ‘Mistletoe for New Year!'”

Myths of the Rhine (1874)

Now that we have a better understanding of why we put up mistletoe—and why we put it up at Christmastime—there’s only one lingering question left to tackle…

Why do people kiss beneath this parasitic plant?

Stay tuned.*

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*Or just learn the answer right now because this article was actually an excerpt from a longer piece, “The Celtic Origins of Kissing Under the Mistletoe at Christmas.”

You can also watch the video essay version on my YouTube channel 👇

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Further Reading

• 50 holiday gift ideas for the Irish mythology-lover in your family
• A Christmas Cornucopia: The Hidden Stories Behind Our Yuletide Traditions by Mark Forsyth
• Christmas In Ritual and Tradition, Christian and Pagan by Clement A. Miles

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Want to learn about the darker side of Irish mythology? Check out…

Samhain in Your Pocket (Celtic Pocket Guides 2)

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Irish Monsters in Your Pocket (Celtic Pocket Guides 3)

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Neon Druid: An Anthology of Urban Celtic Fantasy

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More the listenin’ type?

I recommend the audiobook Celtic Mythology: Tales of Gods, Goddesses, and Heroes by Philip Freeman (narrated by Gerard Doyle). Use my link to get 3 free months of Audible Premium Plus and you can listen to the full 7.5-hour audiobook for free.