Unlike the cross, which in these secular times has been losing its popularity and effectiveness, garlic has grown in esteem as a way to detect or ward off vampires. Garlic has been used since ancient times as an herb and a medicine. It was used as a healing agent before modern medicine, and is even used to this day as a vitamin to strengthen the body's natural defenses to disease. However, its rumoured magical properties are what has made it an effective defense against the vampire. The traditional use is to stuff the vampire's mouth with a head of garlic after the body has been decapitated. Other uses include hanging it around the neck or at the doorway to a home to ward off a vampire attack.
Garlic was also thought historically to be a method by which to detect vampires. In the Slavic countries, a person's aversion to eating garlic meant that they could be a vampire. Hundreds of years ago, it was even distributed in churches to ensure that only humans were attending the service!
The first real literary tie to garlic was in Dracula, where Van Helsing used it around Lucy's neck to keep Dracula away from her, and to keep her from harming others. Since then, garlic has become a major tool in the vampire hunter's kit. Many movies and novels give some reference to its effectiveness, although Anne Rice's The Vampire Chronicles and The Lost Boys both tend to disregard it as a viable form of defense.