Does Witch Hazel Kill Fleas?

Witch hazel turns up in almost every homemade flea spray recipe online. It is usually mixed with vinegar, water and a few drops of peppermint or eucalyptus oil, then sprayed on carpets, pet beds and sometimes the pet itself. The recipes rarely explain how it is supposed to work, and none of them point to a test.

What Is Actually in a Bottle of Witch Hazel

Drugstore witch hazel is a steam distillate made from the twigs and leaves of Hamamelis virginiana, a shrub native to the woods of the eastern United States. It is sold as an astringent, a product that tightens and soothes skin. A typical bottle's label says Purpose: Astringent and lists about 14% alcohol. Some brands sell an alcohol-free version.

That label is the first clue. Witch hazel is a skin product, not a pesticide, and it has never been sold as one.

Does Witch Hazel Kill Fleas?

Nobody has shown that it does. We could not find a single laboratory or field trial of witch hazel against fleas, and fleas are one of the most studied household pests there is.

What entomologists have tested is the wider family of herbal remedies, and the results are not encouraging:

• Ohio State University's flea fact sheet reports that pennyroyal, eucalyptus, rosemary, tea leaves and citronella "have not provided effective control." Garlic, brewer's yeast and B vitamins had no scientific support either.
• Texas A&M AgriLife Extension says the same of garlic, brewer's yeast, cedar bedding and herbal sachets: there is little scientific evidence that any of them control fleas.
• When a homeowner asked extension experts in Maryland about spraying a vinegar, witch hazel and water mix over carpets and furniture, they passed over the recipe and recommended an insect growth regulator instead.

A direct hit with any wet spray might knock down the odd adult flea. That would not solve anything, for reasons that come down to where fleas actually live.

Does Witch Hazel Repel Fleas?

There is no evidence for this either. Fleas do not find a host by smell alone. Ohio State lists what wakes an adult flea and sends it looking for a meal: vibration from footsteps, pressure from an animal lying down, body heat, noise and exhaled carbon dioxide. A faint herbal scent on the carpet does nothing about any of those.

If a homemade spray smells strong enough to seem like it is working, that smell is usually coming from the essential oils in the recipe, and those are the part that can hurt your pets.

Why a Spray Was Never Going to Work

The flea on your dog or cat is almost certainly the cat flea, Ctenocephalides felis. Ohio State calls it the most common flea in and around homes, and it feeds on dogs and people as readily as on cats. Its life cycle is the reason sprays of any kind disappoint.

• Eggs. A female lays 15 to 20 eggs a day and up to 600 in her lifetime. They do not stick to the pet. They drop into carpet, bedding, car seats and the yard, wherever the animal rests.
• Larvae. They hide from light deep in carpet fibers, bedding and lawns, and feed on the dried blood that adult fleas pass, the black specks people call flea dirt.
• Pupae. The larva spins a cocoon, and the adult inside can wait there for up to five months. When a pet or person walks past, it can break out within seconds.
• Adults. Only these live on the animal.

Witch hazel is not in that last column for any stage. Neither is anything else you would spray on the surface of a carpet and let evaporate.

Is Witch Hazel Safe for Dogs and Cats?

Dogs. Witch hazel is not known as a dog poison, but it will not kill the fleas on your dog. Most bottles are about 14% alcohol, which stings skin that is already raw from scratching, and dogs lick whatever you put on them. If your dog's skin is red, scabbed or losing hair from flea bites, that is a vet visit, not a home remedy.

Cats. Cats groom off anything you put on their coat, so whatever goes on the fur ends up swallowed. Do not apply witch hazel to a cat without your vet's OK.

The bigger danger is what the recipes add to it. Veterinary toxicologists at Pet Poison Helpline list peppermint, citrus, tea tree (melaleuca), pine, cinnamon, wintergreen, sweet birch, pennyroyal and ylang ylang oils as toxic to cats. Cats have fewer of the liver enzymes needed to break these oils down. Signs of poisoning include drooling, muscle tremors, trouble breathing, unsteady walking and pawing at the mouth. Several "natural flea spray" recipes online call for exactly these oils.

If your cat has been exposed and shows any of those signs, call your vet or the ASPCA Animal Poison Control Center at (888) 426-4435.

Witch Hazel for Flea Bites: The One Thing It Is Good For

Here witch hazel has real standing. The FDA's rules for over-the-counter skin products list witch hazel as an approved astringent, and allow its label to say it relieves minor skin irritation due to insect bites.

So if fleas have been biting you, dabbing witch hazel on the bites is a reasonable way to take the edge off the itch. The CDC notes that flea bites on people usually land on the lower legs and feet. Bites that keep appearing mean the fleas are still breeding somewhere in the house, and that is the part you need to deal with.

What Actually Gets Rid of Fleas

1. Treat every pet at the same time, with a product your vet recommends. Ohio State notes the most effective pet treatments usually come through a licensed veterinarian. Treat all the dogs and cats in the house, not just the one that is scratching. An untreated pet keeps the eggs coming. Never use a dog flea product on a cat unless the label says it is safe for cats.
2. Vacuum every day for at least two weeks. In a 2007 Ohio State study, vacuuming killed 96% of adult fleas and every larva and pupa tested. The researchers think the brushes and airflow strip the waxy coating fleas need to hold in water. Go slowly over pet resting spots, under cushions, along baseboards and in the car. Vibration also wakes adults waiting in their cocoons, which brings them out where the vacuum and the treated pet can get them.
3. Wash pet bedding and throws in hot water, then dry them hot. Ohio State recommends washing pet bedding regularly, or replacing it.
4. Use an insect growth regulator indoors. IGRs such as methoprene or pyriproxyfen stop larvae from becoming biting adults. The Maryland extension experts called them very effective and safe. Follow the label, and keep pets off treated areas until they are dry.
5. Check the yard where your pet actually rests. Texas A&M notes that flea larvae die when relative humidity drops below 50% or the soil tops 95°F. That is why the source is rarely an open, sunny lawn. It is the shaded, humid spots: under the deck, by the crawlspace door, a shady flower bed, the dog's favorite dirt patch. In a humid Carolina or Virginia summer, shaded spots like these stay damp.
6. Keep going after the bites stop. Depending on temperature and humidity, the full life cycle can run from two weeks to eight months, and pupae can sit in their cocoons for months. Stopping at week two is how fleas "come back."

For the full room-by-room routine, see our guide on how to get rid of fleas.

When to Call a Professional

Home treatment works for a lot of flea problems if you do all of it: every pet, every day, for weeks. It is worth calling us when:

• You have treated every pet and vacuumed daily for three weeks and you are still getting bitten.
• You have come back to a house that was empty for a while and fleas jump on your legs as you walk in. Pupae wait for exactly that moment.
• There is a lot of carpet, several pets, or a crawlspace or deck where animals have been sleeping.

On a flea job we treat the yard and, when pets are affected, the carpets, baseboards and pet rest areas inside. We coordinate with your veterinarian's flea prevention for your pets, and time re-treatments to the flea life cycle, every 3 to 4 weeks in peak season. If fleas return between scheduled treatments, we come back and re-treat at no extra charge. Our flea and tick service covers homes across South Carolina, North Carolina and Virginia.

For what to expect, see when to call an exterminator for fleas and how to prepare for a flea treatment.

Sources: D. J. Shetlar and J. E. Andon, "Fleas", Ohio State University Extension HYG-2081-11, 2012; W. F. Hink and G. R. Needham, "Vacuuming is lethal to all postembryonic life stages of the cat flea, Ctenocephalides felis", Entomologia Experimentalis et Applicata, 2007; M. Merchant and J. Robinson, "How to Get Rid of Fleas", Texas A&M AgriLife Extension; Maryland Home & Garden Information Center, Ask Extension answer, 2017; R. Schmid, A. Brutlag and C. Flint, "Essential Oil and Liquid Potpourri Poisoning in Cats", VCA Animal Hospitals / Pet Poison Helpline; U.S. Food and Drug Administration, 21 CFR 347.52, labeling of astringent drug products; Centers for Disease Control and Prevention, "About Fleas".

Photo credits: National Park Service, public domain, via Wikimedia Commons.