"The offensiveness of the breath of him that hath eaten Garlick, will lead you by the nose to the knowledge hereof, and (instead of a description) direct you to the place where it grows in gardens, which kinds are the best, and most physical."
-Culpepper's Complete Herbal and English Physician
Garlic is a member of the genus Allium, which includes onions, leeks, shallots, and chives. Garlic is known for its pungent scent, its sharp and spicy flavor, and for being one of the primary defenses against vampires and evil spirits. For centuries, if not millennia, garlic has been used in cooking, and as medicine (even as an antiseptic). Even today, garlic is recommended if you're feeling sick, and has a great number of medicinal properties (personally, I do consume more garlic if I feel a cold coming on, and it does help). I won't be getting into the practical culinary and medicinal qualities, because the focus today is on garlic as a protective herb.
Every year, my house gets an infestation of fruit flies. It's manageable, but painfully annoying. This year they came late, the warm Autumn being just enough to keep them alive. I place apple cider traps. I wash and clean everything. Their presence is insidious, anxiety-inducing. We have been careful to cover everything and put all fruit and veg in the fridge, but one thing can always remain on the counter. Bulbs of garlic, wrapped in their papery skin. My wife made a garlic sauce, and the flies were staying far away from it. Delicious for us, but too much for those pests.
I have a natural proclivity for protection magic, which apparently extends to hexing and banishing. Protection magic is one of my special skills, and it comes naturally to me. As such, I tend to do a lot of research into historical protection magic. I like understanding how different herbs or tools came to have the correspondences they do, and how their uses have evolved to be used by modern witches like myself. One interesting through line that I see with protection magic is a very real connection to something's practical uses as medicine, and/or as deterrents against insects and vermin.
Historically, there has been a lot of folklore around the idea of evil spirits (included witches) transforming into unwanted pests in order to enter homes. Or, in the case of some witches, using familiars in the form of such pests to enter spaces. Cracks where something may enter would be painted white with plaster, making it impossible for a shadowy creature to blend in, but also sealing the crack against small creatures like insects. Dead cats would be sealed in chimneys and walls to protect against these otherworldly menaces (did this start after a cat got into a wall by accident, while pursuing mice?). Garlic would be hung in homes, and it's said that garlic juice would be rubbed on the inside of locks (if you've seen old keyholes in medieval homes, you can see how insects would crawl in).
In many cultures, garlic is associated with the Underworld. Garlic was once used in offerings to Hecate, and according to Beyerl in A Compendium of Herbal Magick, this tradition has continued. In the realm of protection magic, this is an interesting correspondences. While Hecate is not directly a protection goddess, she is a bringer of light (like those plastered cracks in old homes) and sees over entryways (including doorways, the same that some would hang garlic around). These aren't solid connections by any means, but I do think they're interesting.
What makes humans like the taste of garlic is the same thing that deters other animals. We've acquired a taste for it, but the strong scent is too much for most animals. Insects and mice, both common nuisances in a home, do not like garlic. They will not touch it. You can even make a garlic spray to spray on entry points, making mice quite reluctant to enter a space.
Garlic isn't unique in its connection to protection magic by way of practical means. Lavender, sage, peppermint, cedar, catnip, and citrus (to name a few, but the list goes on) are all plants that deter vermin and/or insects, and also largely have positive affects on humans. Herbs and holy woods that are burned (like sage and cedar) clear evil spirits, but are also very effective in removing insects from a space.
One of my mantras (so to speak), is 'magic is real.' This doesn't mean that I believe in an ability to wave a wand and conjure something out of thin air (but let's be real, I don't think that's totally impossible. I'd rather believe that such things could be achieved, because it's more interesting to believe that anything is possible). I mean that so much of what we use in magical practices and rituals have been handed down for generations, from healers and midwives. So much of magic is practical that is has to be real. If smoke calms bees, why wouldn't it work with unseen forces? The colour white is associated with purity because it's easy to see if it's dirty. If garlic helps remedy a sore throat or a cold, why wouldn't it help when it comes to more metaphysical aspects? Choosing ingredients to make a meal that will nourish, sustain, and heal is incredibly magical. It's alchemical.
People of yore, our ancestors, understood the practical aspects of all of these things. They weren't just wildly superstitious, uneducated people. We like to point to their practices that have evolved into magic as foolish and ignorant, but they understood a lot of incredibly poignant truths for their time. Fortunately for us, some of these truths are still useful today. We might even have more information about why they work, allowing us to better use certain medicines to our advantage.
So, while vampires might not be real (but again, I won't close myself to the possibility), garlic is an incredibly protective and magical plant. Next time you're cooking with garlic, or enjoying a meal with that spicy something that garlic offers, know that you're protected. Spiritually, and maybe even against a nasty cold.