The Druids believed the holly or ilex was sacred. They thought this plant stayed green year round because it was especially favored by the sun. Christian legend says one winter night, the holly miraculously grew leaves out of season in order to hide the Holy Family from Herod's soldiers. Since then, it has been an evergreen as a token of Christ's gratitude. My guess is that the story originated from a holly farmer who was sitting around the farm asking, "what the hell am I going to do with all this crap?"
Holly is one of the trees said to be the tree of Christ's cross. For those of you keeping track, I think we're up to ten varieties of tree now? Some legend tells us that the trees of the forests refused the defilement of the cross, splintering into tiny fragments at the touch of the ax. Only the holly behaved like an ordinary tree, allowing itself to be cut and formed into a cross. It is as a Passion symbol that holly is found in pictures of various saints. It's presence indicates that the saint is either reflecting upon Christ's Passion or foretelling it. Again with the foreshadowing. There's more death than birth in this whole advent scene - if you're paying close attention.
In Germany, holly is called Christdorn in memory of Christ's crown of thorns. According to legend, the holly's branches were woven into a painful crown and placed on Christ's head while the soldiers mocked him saying, "Hail, King of the Jews." The holly's berries used to be white but Christ's blood left them with a permanent crimson stain.
Another made up tale says that a little orphan boy was living with the shepherds when the angels came to announce the birthday party. Having no gift for the baby, the child wove a crown of holly branches for its head. But when he lay it before Christ, he became ashamed of it's poverty and began to cry. Miraculously, Jesus touched the crown and it began to sparkle while the orphan's tears turned into beautiful scarlet berries. That's about as realistic as the drummer boy giving a drum solo to a newborn. No, being allowed to give a drum solo to a newborn.
There are some superstitions surround the holly. But you say superstition if it's not part of the recognized church legend, only someone else's beliefs. It is a man's plant and is believed to bring good luck and protection to men while ivy brings the same to women. It is thought that whoever brings the first sprig of Christmas holly into the home will wear the pants that year. It was hung about the doors and windows to keep away witches, spells, evil spirits, goblins, and lightning. On Christmas eve, English virgins hung holly on their beds to protect their virtue from Christmas goblins. However, elves and fairies were welcome in British households, and sprigs of holly were hung as hiding places for them.
Romans gave gifts of holly to their friends during Saturnalia as good luck charms and protection against evil. Because of all these superstitions, early Christians were forbidden to decorate with this plant, especially during Saturnalia. Funny how easily it was adapted into the Christian solstice celebration?