Why Do We Kiss Under Mistletoe and Where the Custom Began

Someone hangs a sprig of green leaves and white berries over a doorway in December, and suddenly everyone is expected to kiss whoever stands beneath it. It is an odd custom when you stop to think about it, and most people who follow it have no idea why we kiss under mistletoe at all.

The short answer is that the habit is younger than most people assume, and the ancient stories often quoted as its origin have a weak link to kissing. The longer answer takes in Roman writers, Norse myth, English servants' halls and a plant that grows without roots in the soil. Here is what we actually know.

What mistletoe is and why it seemed magical

European mistletoe, Viscum album, is a hemiparasite. It grows on the branches of host trees such as apple, lime, poplar and, more rarely, oak, and draws water and minerals from them while making its own food through photosynthesis. Birds eat the sticky berries and wipe or pass the seeds onto new branches, which is how the plant spreads.

To people in the past, this was strange. Here was a plant that stayed green in the dead of winter, grew high in a tree with no roots in the ground, and bore fruit when almost nothing else did. The English name hints at how people saw its spread: it comes from Old English mistiltan, often read as "dung on a twig", a nod to those birds.

A plant that seemed to live between earth and sky, and stayed alive through winter, naturally picked up meanings around life, fertility and protection.

The ancient stories behind why we kiss under mistletoe

Two old sources turn up in nearly every article about mistletoe. Both are real, but neither describes kissing.

Pliny and the druids

The Roman writer Pliny the Elder, in his Natural History written in the first century AD, described Gaulish druids cutting mistletoe from an oak on the sixth day of the moon. A priest in white robes climbed the tree, cut the plant with a golden sickle, and two white bulls were sacrificed. Pliny says the druids believed a drink made from mistletoe could make barren animals fertile and protect against poisons.

Because mistletoe on oak is rare, finding it was a big event. That is the source of the fertility link that later writers connected with kissing.

Baldur and the Norse myth

In Norse mythology, the goddess Frigg asked every living thing to swear never to harm her son Baldur. She skipped mistletoe, thinking it too young and small. The trickster Loki made a dart or spear from it, and Baldur was killed. In some modern retellings, Frigg's tears become the white berries and she declares mistletoe a symbol of love. That happy ending, however, does not appear in the medieval Icelandic sources. It seems to be a much later addition.

When people actually started kissing under mistletoe

The kissing custom shows up clearly in England in the 18th century. Mistletoe was already part of Christmas greenery, and at some point a branch or a "kissing bough" hung in the house came with a rule: anyone caught standing under it could be kissed, and refusing was thought to bring bad luck.

By the early 19th century it was common enough to be written about with a wink. The American writer Washington Irving, describing an English country Christmas in 1820, noted that young men plucked a berry from the bush each time they kissed a girl beneath it, and when the berries ran out, the privilege ended. That berry rule is a neat detail: a sprig with 12 berries allowed 12 kisses.

The Victorians turned it into a household tradition and sent it around the world through Christmas cards, novels and emigration. Charles Dickens has Mr Pickwick kissed beneath the mistletoe at the Dingley Dell Christmas party in The Pickwick Papers, published in 1836 and 1837, which helped fix the image in readers' minds. The custom crossed to North America, where native mistletoe species of the genus Phoradendron stood in for the European plant.

Why the "ancient pagan ritual" story falls short

You will often read that kissing under mistletoe is a direct survival of druid or Norse fertility rites. It makes a good story, and it is the explanation people repeat at parties. The evidence does not really support it.

Pliny writes about cutting mistletoe and using it as a remedy, not kissing beneath it. The Norse myth is about a death, and the love symbol ending was added by later storytellers. Between those sources and the first clear records of mistletoe kissing in England, there is a gap of well over a thousand years with almost no evidence of the practice.

A more likely explanation is plainer. Evergreen plants had long been brought indoors in winter, mistletoe already carried a vague reputation for luck and fertility, and a playful household game grew up around it. It is the same pattern seen with other customs, from why people knock on wood to why we clink glasses when we toast: a real old belief gets a much newer social habit attached to it, and the story of a grand ancient origin follows later.

Mistletoe today and a few practical points

England still has a strong mistletoe trade. The market town of Tenbury Wells in Worcestershire has held winter mistletoe and holly auctions for well over a century, and much of the mistletoe sold in British shops comes from old apple orchards in that area.

If you hang some at home, keep a few things in mind:

• The berries and leaves are toxic if eaten. Hang it high, out of reach of children, dogs and cats, and sweep up any fallen berries.
• Fresh mistletoe lasts about two to three weeks indoors. Keep it away from radiators and mist it with water every few days.
• Do not cut it from trees you do not own. Buy it from a market or a grower.
• Old custom says the sprig should be burned or thrown out on Twelfth Night, though many people keep it until the next year for luck.

For more on why we do the things we do without thinking, browse the rest of our culture explainers.

Frequently asked questions

Where did the tradition of kissing under mistletoe come from?

The kissing custom is first clearly recorded in England in the 18th century, as part of Christmas house decorations. Older beliefs about mistletoe and fertility, described by Roman writers, probably helped it catch on. There is no solid evidence that ancient druids or Norse people kissed under it.

What does it mean if you refuse a kiss under mistletoe?

In older English folklore, refusing a kiss under the mistletoe was said to bring bad luck in love for the coming year. Today it means nothing at all, and nobody should feel pushed into a kiss by a plant. Most people now treat it as a joke rather than a rule.

Is mistletoe poisonous to touch?

Touching mistletoe is generally safe for adults, but eating the berries or leaves can cause stomach upset and, in larger amounts, more serious symptoms. Pets and small children are most at risk. Wash your hands after handling it and hang it well out of reach.