Most spider repellents fall into three categories: essential oils, chemical barrier sprays, and physical exclusion. Some work well, others are a waste of money, and a few popular remedies have no scientific backing at all. Here’s what actually keeps spiders out of your home and what you can skip.
Essential Oils: Peppermint Works, Lemon Doesn’t
Peppermint oil is the most commonly recommended natural spider repellent, and it does have some science behind it. In controlled choice tests, brown widow spiders and European garden spiders avoided peppermint oil more than 75 percent of the time. Chestnut extract performed similarly well against those same species. Lemon oil, despite being one of the most frequently recommended remedies online, had no significant repellent effect on any of the three spider species tested.
The catch is that results varied by species. A third spider in the study, the false widow, wasn’t bothered by peppermint or chestnut at all. So peppermint oil can discourage some spiders in some situations, but it’s not a reliable, universal solution. To use it, mix 15 to 20 drops of peppermint essential oil with water in a spray bottle and apply it around windowsills, door frames, and baseboards. You’ll need to reapply every few days as the scent fades.
Vinegar as a Spider Deterrent
White vinegar is a cheap, accessible option. The acetic acid it contains irritates spiders’ sensory organs, making treated surfaces unpleasant for them. A 50/50 mix of white vinegar and water sprayed around entry points can deter spiders from crossing those areas. Adding vinegar to mop water also helps keep floors and corners less inviting.
Vinegar won’t eliminate a spider population, and its smell fades within a day or two, requiring frequent reapplication. Direct contact with full-strength vinegar can kill individual spiders, but as a repellent strategy it works best as one layer of a broader approach rather than a standalone fix.
Chemical Barrier Sprays
For persistent spider problems, synthetic insecticide sprays create a residual barrier that kills spiders on contact for weeks after application. Products containing bifenthrin, cypermethrin, or similar active ingredients are available at most hardware stores in ready-to-use liquid formulations. You apply them along baseboards, around windows and doors, and along the foundation exterior.
These products are genuinely effective, but they’re broad-spectrum insecticides that kill beneficial insects too. If you’re dealing with a handful of harmless house spiders, a chemical barrier is overkill. Reserve it for situations where you’re seeing large numbers of spiders or species you’re concerned about, like brown recluses or black widows.
Remedies That Don’t Work
Conkers (horse chestnuts) placed around the house are one of the most persistent spider myths. There’s no scientific evidence they repel spiders. A school project that won a Royal Society of Chemistry prize in 2010 tested the idea directly and found spiders were completely unbothered by them. Since spiders don’t eat chestnuts or interact with horse chestnut trees in any meaningful way, there’s no evolutionary reason the trees would produce spider-repelling chemicals.
Ultrasonic pest repellers are another popular but ineffective option. The U.S. Federal Trade Commission has sent warning letters to more than 60 manufacturers of these devices for making unsupported efficacy claims. Between 1985 and 2001, the FTC brought enforcement actions against six companies for false advertising. Previous FTC complaints found that even when pests initially react to ultrasound, the response is temporary, and they return to the area once they get used to it. The agency specifically noted that ultrasound devices do not control insects, and spiders (which are arachnids, not insects) are even less likely to respond.
Physical Exclusion: The Most Reliable Approach
Sealing entry points is the single most effective way to keep spiders out. Caulk cracks in your foundation and around window frames. Install or repair screens on windows and doors. These steps physically prevent spiders from getting inside, which no repellent spray can guarantee.
Beyond sealing gaps, reducing what attracts spiders in the first place makes a real difference. Spiders go where their prey is, and their prey is drawn to light. Switching outdoor bulbs to yellow light bulbs reduces the number of flying insects congregating near your home at night, which means fewer spiders follow them in. Keep vegetation, especially ivy and dense ground cover, at least 12 inches away from your foundation so spiders don’t have a sheltered path right up to your walls.
Inside, regular vacuuming and dusting removes both spiders and their webs. A cobweb brush or vacuum attachment used in corners, ceiling edges, and behind furniture disrupts established spiders and discourages new ones from settling in. Clutter gives spiders hiding spots, so reducing storage boxes, piles of clothes, and undisturbed spaces in basements and garages cuts down on the places they can set up.
Essential Oil Safety Around Pets
If you have cats or dogs, be careful with essential oil sprays. Cats are especially sensitive to essential oils because their livers lack certain enzymes needed to process them. Dogs are also at risk: as little as seven drops of pure tea tree oil can cause severe poisoning in a dog. Peppermint oil, eucalyptus, and tea tree oil are all commonly used in spider repellent recipes and all pose a risk to pets.
Early signs of essential oil toxicity in dogs include drooling, lip licking, and decreased appetite. These can progress within minutes to hours to vomiting, muscle tremors, difficulty breathing, or an unsteady walk. If you use essential oil sprays, apply them only in areas your pets can’t access or lick, and never use a diffuser in a small, enclosed room where a pet spends time. Vinegar is a safer alternative in homes with animals.
Putting It All Together
The most effective spider control combines physical exclusion with habitat management. Seal your home’s entry points, swap outdoor lights to yellow bulbs, keep vegetation trimmed back from the foundation, and vacuum regularly. Peppermint oil or vinegar sprays add a mild deterrent layer but won’t solve the problem alone. Chemical barrier treatments are effective for serious infestations. Skip the conkers and ultrasonic devices entirely.