"I don’t understand that thing about the garlic at all – do they have to eat it, or –"
--Neville Longbottom (PA14)
Garlic is useful for seasoning food and for warding off vampires (PS8).
Students attributed the strong smell of garlic in Professor Quirrell's classroom to his use of the pungent plant to protect himself from vampires (PS5). Fred and George also believed Quirrell kept garlic in his turban out of an abundance of caution against vampires (PS8).
In an advertisement for a job with their organization, the Society for the Toleration of Vampires said that they would give preference to candidates with a "garlic allergy" (DP2).