One of the strongest reminders that we have entered the (ever-lengthening) holiday season is that first scent of evergreen. But while the smell of fir, pine, or spruce may be one of the most familiar parts of Christmastime, there are plenty of things about the beloved conifers that may not be so well-known. From surprising early holiday practices to current research being conducted to build a better tree, here are some lesser-known facts of these features of the holidays.

1. THE EARLY CHURCH DID NOT LIKE THEM.

Evergreen trees used to be seen as hedonistic, pagan symbols that had no place in connection with a religious celebration. As far back as 1647, preacher Johann Conrad Dannhauer of the Strasbourg Cathedral criticized trees as “child’s play” that were getting more attention “than the word of God and the holy rites.” In the U.S., puritan governor William Bradford railed against the tree’s “pagan mockery.”  The trees’ connection with the celebration of the winter solstice, which generally fell on December 21 or 22, was seen as antithetical to a proper Christian gathering. But as the tradition persisted, church leaders decided that if they couldn’t beat the decorated trees, they would co-opt them as part of their own Christmas celebration.

2. IN SOME HOMES, TREES WERE HUNG.© Getty Images

In southwest Germany during the 17th and 18th centuries, it was popular, particularly among the lower classes, to hang smaller trees from the ceiling or rafters. This allowed for a flashy display, but kept the goodies in the tree out of the reach of children. Some families even hung the tree upside-down, since “pointing the root toward heaven was supposed to imbue the tree with divine powers,” according to Bernd Brunner in his book Inventing the Christmas Tree. In other German households, “Christmas pyramids” built of wood and covered with evergreen branches and candles would serve as the centerpiece of celebrations. 

3. A PRINCE IS CREDITED WITH POPULARIZING THEM IN AMERICA.

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England’s Prince Albert is credited with helping bring the Christmas tree from his native Germany to the English-speaking world, making it a well-publicized tradition in the royal household of his wife, Queen Victoria. Godey’s Lady’s Book editor Sarah Josepha Hale—one of the main advocates for a national Thanksgiving holiday—played an important role in promoting Christmas trees in the U.S. when her magazine published an illustration of the British royal family with their tree in 1850. She edited out Victoria’s crown jewels, Albert’s mustache and sash, and any reference to who the family were, transforming the picture from a piece of royal marketing to a paragon of middle-class, American, Christmas celebration. Albert would remain associated with the Christmas tree for years. Following his death on December 14, 1861, English families living in New York City reportedly draped their trees in black in honor of his memory.

4.  THE FIRST CHRISTMAS TREE MARKET LAUNCHED IN 1851.

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One thing slowing the adoption of Christmas trees was the burden most families faced of having to find and chop down their own trees. That began to change in 1851, when anenterprising logger from New York’s Catskill Mountains loaded dozens of fir and spruce trees from his land (usually used for barrel-making), and hauled them down to New York City’s Washington Market. The harvested trees, ready to set in a living room and decorate, sold out fast and kicked off the practice of Christmas tree farms, which quickly proliferated throughout the country.

5. GIFTS USED TO GO IN THE TREE, NOT UNDER IT.

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In its first decades in the U.S., Christmas trees held gifts in their branches more often than under them. Typical 1870s reports describe a “monster Christmas tree despoiled of its pendent treasures of candy, dolls, and toys of all descriptions” and a “mammoth Christmas-tree literally covered with pendent treasures.” Often these gifts included fruit, cakes, and candy that children would just pluck directly from the tree and enjoy.

6. THEY CAN BE EXTREMELY DANGEROUS.

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From their earliest days, Christmas trees have been fire hazards. Before electric lights were introduced, many families set open candles on their trees to illuminate them, which meant that each Christmas morning, the newspapers included stories of homes going up in flames when the branches ignited. Even when families abandoned the obvious hazard of open flames on the trees, the conifers could still cause major trouble once they dried out. In Philadelphia in 1878, Christmas trees caused two fires on the same street, first when a gas jet ignited a tree in a brownstone, then later that day when a dressmaker’s in-store tree went up. Today, trees can still pose a hazard if they are allowed to dry out.

7. NEW YORK’S BIG TREE DIDN’T USED TO BE IN ROCKEFELLER CENTER.

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While Rockefeller Center and Christmas trees go hand-in-hand, NYC used to hold its big citywide celebration in Madison Square Park. Beginning in 1912, it was this location where thousands would gather to watch the lighting of the “Tree of Light” (as it was called, rather than “Christmas tree”). The party shifted to midtown Manhattan in 1933, where it has been ever since.

8. GERMANS DON’T CALL IT A TANNENBAUM.

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The most famous song about a Christmas tree may be “O Tannenbaum,” but in German, the word tannenbaum just refers to a general fir tree. The actual German word for “Christmas tree” is usually weihnachtsbaum, which would probably have made for a less catchy song.

9. THEY ARE BIG BUSINESS.

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Some 25–30 million Christmas trees are sold in the U.S. every year, according to the National Christmas Tree Association, making it about a $1 billion industry. The trees are grown at almost 15,000 farms in all 50 states, though the biggest producers are Oregon, North Carolina, Michigan, Pennsylvania, Wisconsin, and Washington.

10. RESEARCHERS ARE BUILDING A BETTER TREE.

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All those pine needles that accumulate below the tree each day may soon be a thing of the past. Washington State University plant pathologist Gary Chastagner, also known as “Mr. Christmas Tree,” is currently leading a five-year, $1.3 million research project partly aimed at helping Christmas trees retain their needles for longer. Chastagner and a team of researchers are collecting tree samples from farms throughout the country, testing which are the most resistant to root rot and have the strongest needle retention, then sourcing those for seeds to plant the next crop of Christmas trees. If the team succeeds, your tree may last into the spring. 

11. THEY ARE VERY THIRSTY.

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Each day, Christmas trees need a minimum of one quart of water per inchof diameter at their base. That’s far more water than many tree stands on the market are able to hold. In a test of 30 tree stands, Chastagner found that only two could contain enough water for all the tree sizes they were supposed to hold. About a quarter of them couldn’t even accommodate the hydration needs of the smallest tree they could hold. (In 2007, Chastagner tested whether Christmas trees could be hydrated with an I.V. drip, but that worked even less effectively than a traditional tree stand.)