In this Christmas season, it's especially important to keep your home free of witches, warlocks, and other demons. Fortunately, one of the best loved of Christmas greens will do nicely for this purpose. The Holly, from ancient times, was used by the people of Europe to protect their homes from evil spirits. Witches and warlocks, it seems, are deterred from entering by the holly's prickly leaves and also by its reputation for holiness (the word "holly" comes from holy). So there you are. Decorate your home and protect it with one useful plant.