Ever wonder why you eat candy canes at Christmas? Why poinsettias are popular seasonal plants? Or the backstory of the Elf on the Shelf? Read on for a bit of history into five well-known holiday traditions.

*Holiday Gingerbread

According to The Spruce Eats, German settlers brought gingerbread houses, known as lebkuchenhaeusle, to America. The sweet houses became popular there after the Brothers Grimm published their "Hansel and Gretel" fairy tale in the 19th century.

Gingerbread, which typically is made with ginger, brown sugar, molasses, cinnamon, cloves, cardamom, nutmeg and anise, is also popular for cookies, including gingerbread people.

Queen Elizabeth I gets credit for the first gingerbread man after she presented visiting dignitaries gingerbread cookies in their own likeness. Gingerbread was popular at fairs, and when gifted, it was symbolic of love.

The largest gingerbread house, as certified by Guinness World Records, was created in 2013 by the Texas A&M Traditions Club in Bryan, Texas. It measured 60 feet long, 42 feet wide and 10 feet tall. Entirely edible, the house had 35,823,400 calories.

*Christmas Trees

Throughout time, evergreen trees -- those that remain green throughout the year, such as pine, fir and spruce -- were believed to keep away evil spirits, ghosts, witches and even illness. That's according to History.com, noting that's how the tradition started of hanging evergreen boughs over doors and windows.

The idea of having decorated Christmas trees in the house comes from Germany, where 16th-century devout Christians had decorated trees inside their homes. Protestant reformer Martin Luther is credited as the first to add lighted candles to a Christmas tree. He was inspired after walking home at night and seeing twinkling stars and evergreens.

German settlers brought Christmas trees to America, but the trees there were largely seen as pagan symbols. Trees didn't become mainstream until 1846, when Queen Victoria and her German prince, Albert, posed by their Christmas tree for an illustration. Soon, Christmas trees were fashionable. Over the years, trees got more elaborate, starting with homemade ornaments, popcorn garland and, later, electric lights.

*Candy Canes

History.com says 1.76 billion candy canes are produced in the U.S. every year.

Like many Christmas traditions, the candy cane has German origins. One theory is that in 1670, a choirmaster at the Cologne Cathedral in Germany gave his young singers sugar sticks bent like shepherd's hooks to keep them quiet during the living nativity. Another theory is that a German choirmaster gave his singers candy sticks to keep them occupied and quiet during services.

The candy canes eventually made their way to America. In 1847, a German-Swedish immigrant in Wooster, Ohio, decorated a small blue spruce tree with paper ornaments and white candy canes. Over time, candy canes got their red, peppermint stripe. Nowadays, they're available in even more colors and flavors.

*Poinsettias

This next tradition has Mexican roots. Almanac.com reports that American statesman and the first U.S. ambassador to Mexico, Joel Roberts Poinsett, also an amateur botanist, saw the red-flowered plant when he was visiting the Mexican town of Taxco.

He sent cuttings of the plant back to his plantation in South Carolina and called it the "Mexican Fire Plant." The plant became popular and was renamed in his honor.

But poinsettias didn't become mainstream until Californian Paul Ecke started growing the plants at his ranch. He discovered a technique that resulted in a fuller plant. Soon he was growing tens of thousands of poinsettias for the Christmas season. He promoted them by sending them to TV studios across the country. The plants became a seasonal success and are nationally recognized on Dec. 12, National Poinsettia Day.

These days, poinsettias are the most popular Christmas plant, and they're the best-selling potted plant in the U.S. and Canada.

*The Elf on the Shelf

Here's the story behind a modern tradition: the Elf on the Shelf.

The Huffington Post spent time with the elf's creators and got the backstory. Carol Aebersold grew up with an elf, Fisbee, when she was a kid, but he was an ornament on the tree and didn't move.

She continued the tradition for her twin daughters, Chanda Bell and Christa Pitts, in the 1970s. But the tradition changed. The girls believed Fisbee flew around the house at night and reported back to Santa Claus about their respective behavior. Aebersold told the girls not to touch the elf because it would lose its magic.

Fast forward to 2004, when one of Aebersold's daughters decided to write a story about the Elf on the Shelf. It was just a fun project at first but it become a huge business over time. These days, over 11 million elves have been sold across the world.