The most effective home remedy for spiders isn’t a single trick but a combination of sealing entry points, reducing what attracts them, and using natural repellents in key areas. Spiders follow their food supply, so anything that cuts down on insects inside your home will cut down on spiders too. Here’s what actually works, what doesn’t, and how to do it safely.
Seal Entry Points First
Spiders can squeeze through gaps as small as 1/16 of an inch, which means most homes have dozens of potential entry points. Before you try any repellent, closing those gaps gives you the biggest return on effort. Focus on these areas:
- Exterior doors: Install door sweeps at the base of every outside door, and run a bead of caulk along the bottom outside edge and sides of the threshold. Pay extra attention to the bottom corners, which are the most common insect and spider entry points.
- Windows: Caulk any cracks around window frames using silicone or acrylic latex caulk. Repair tears in window screens immediately.
- Utility openings: Seal gaps where pipes, wires, outdoor faucets, gas meters, dryer vents, and cable lines enter your foundation or siding. These can be plugged with caulk, expandable foam, steel wool, or copper mesh.
- Garage doors: Fit the bottom with a rubber seal (vinyl cracks in cold weather and leaves gaps).
- Sliding glass doors: Line the bottom track with half- to three-quarter-inch foam weatherstripping.
- Vents: Cover attic, roof, and crawl space vents with quarter-inch wire mesh hardware cloth.
This kind of exclusion work takes an afternoon and a tube of caulk, but it’s far more reliable than any spray or powder on its own.
Cut Down on Insects That Attract Spiders
Spiders set up where food is plentiful. If your porch light draws clouds of moths and gnats every evening, spiders will build webs nearby and eventually find their way inside. Switching to a yellow “bug bulb” or replacing a constant porch light with a motion-activated one dramatically reduces the insect swarm, and with it, the spider population around your doors.
Inside, the same principle applies. Keep kitchen counters clean, take trash out regularly, and fix any moisture issues like leaky pipes or standing water in basements. Fewer flies and gnats means fewer reasons for spiders to stick around. Clearing clutter in garages, closets, and storage areas also removes the sheltered spots spiders prefer for web-building.
Peppermint Oil and Other Essential Oils
Peppermint oil is the most popular natural spider repellent, and while hard scientific evidence is limited, there’s substantial anecdotal support. The working theory is that spiders taste and smell through their legs, so they avoid crawling through strong-scented oils. Essential oils also contain compounds called monoterpenoids, which have fumigant properties that may play a role in repelling arthropods. One study found peppermint oil repelled Argentine ants for up to seven days after application, and researchers concluded essential oils are viable alternatives to chemical repellents for home-invading pests including spiders.
To make a spray: add about five drops of peppermint oil to a 16-ounce spray bottle filled with water and a small squirt of dish soap, then shake well. Spray along windowsills, doorframes, baseboards, and any corners where you’ve noticed webs. Reapply every week or so, since the scent fades. Other oils people use include tea tree, lavender, and eucalyptus, though peppermint has the most widespread reputation.
Essential Oil Safety Around Pets
If you have cats or dogs, choose your oils carefully. Tea tree oil is the most commonly reported cause of essential oil poisoning in pets. Eucalyptus, cedar, pennyroyal, wintergreen, and birch oils can trigger seizures in animals. Cinnamon oil and pennyroyal are potentially toxic to the liver. Wintergreen and birch contain high levels of a compound that acts like aspirin in the body, which is dangerous for both cats and dogs.
Peppermint oil is generally considered lower risk, but cats are more sensitive to essential oils than dogs because they lack certain liver enzymes needed to process them. If you use any oil spray, apply it in areas your pets can’t reach or lick, and ventilate the room well.
Diatomaceous Earth
Food-grade diatomaceous earth is a fine powder made from fossilized algae. It works mechanically, not chemically. The tiny particles have sharp edges that scratch through a spider’s outer coating, causing it to lose moisture and dehydrate. It also absorbs oils and fats from the exoskeleton, speeding up the drying process. It remains effective as long as it stays dry and undisturbed.
Dust a thin layer along baseboards, behind appliances, in crawl spaces, and around the perimeter of rooms where spiders are a problem. A little goes a long way. The main precaution is avoiding inhalation: the fine dust can irritate your lungs, so wear a simple dust mask when applying it and keep it away from areas where children or pets might stir it up into the air. Only use food-grade diatomaceous earth indoors, not the pool-grade variety, which is processed differently and poses a greater respiratory risk.
White Vinegar
A 50/50 mix of white vinegar and water works as a contact spray. The acetic acid in vinegar irritates and can kill spiders on direct contact, though it doesn’t leave a long-lasting residual barrier the way diatomaceous earth does. It’s most useful as a quick response when you spot a spider or a fresh web. Spray directly onto webs, corners, and crevices. The smell dissipates within an hour or so, which makes it less useful as a preventive repellent compared to essential oils.
What Doesn’t Work: Horse Chestnuts
Placing horse chestnuts (conkers) around your home is a widely repeated folk remedy. There is no scientific evidence that it works. Spiders don’t eat conkers or lay eggs in them, so horse chestnut trees have no evolutionary reason to produce spider-repelling chemicals. When students at a primary school in Cornwall tested this claim in an informal study that won a Royal Society of Chemistry prize in 2010, they found spiders were completely unbothered by the presence of conkers. Save yourself the effort.
Venomous Spiders Require a Different Approach
Home remedies are reasonable for the common house spiders, cellar spiders, and garden spiders that make up the vast majority of household encounters. They are not adequate if you’re dealing with black widows or brown recluses, the two North American spiders whose venom is dangerous to humans.
Brown recluse bites often develop a distinctive bruise-like discoloration, described as a red, white, and blue pattern, within one to three days. About 10% of severe cases require surgical cleaning and sometimes a skin graft. Black widow bites cause localized redness initially, followed within 30 minutes to 10 hours by spreading pain, muscle cramping, spasms, and potentially body-wide symptoms like abdominal pain, nausea, and vomiting.
If you’re finding either of these species in your home, professional pest control is worth the cost. And if you’re bitten and develop symptoms beyond localized irritation, such as muscle cramping, changes in urine color, difficulty breathing, hives, or swelling that worsens over several days, that’s a situation for urgent medical care, not home treatment.
Putting It All Together
The most effective approach layers these methods. Start with exclusion: seal gaps, fix screens, and weatherstrip doors. Then reduce what draws spiders in by managing outdoor lighting and keeping indoor spaces clean and dry. Use peppermint oil spray along entry points and common web spots weekly, and apply diatomaceous earth in hidden areas like behind furniture and along basement walls. Knock down webs regularly, because removing a web repeatedly encourages spiders to relocate. A spider that rebuilds three or four times in the same spot with no catch will eventually move on.
None of these remedies creates an impenetrable barrier, but together they make your home a much less appealing place for spiders to settle. Most people who combine sealing with one or two repellent methods notice a significant drop in spider activity within a few weeks.