Peppermint beat lemon in a lab test, and a few simple habits do the rest. Every fall, the same thing happens. Temperatures drop, and spiders start showing up in corners, bathtubs and window frames. Many are males looking for mates, and some are simply seeking shelter. Most households reach for a chemical spray, but there is a gentler option that science actually supports.
What the Study Tested
Researchers led by Andreas Fischer, then a master’s student at Simon Fraser University in Canada, tested three natural remedies that are widely recommended online: peppermint oil, lemon oil and chestnuts. Their study, published in the Journal of Economic Entomology, used three spider species: the brown widow, the false black widow (Steatoda grossa) and the European garden spider, according to Entomology Today.
In Y-shaped tube tests, each spider could choose between an arm with the scent and an arm without it.
Peppermint Worked, Lemon Did Not
Peppermint oil repelled two of the three species, the brown widow and the garden spider, which avoided it in more than 75 percent of tests. The false black widow showed no significant reaction.
Lemon oil, despite being the remedy that appeared most often in the team’s online searches, had no significant effect on any of the three species. Chestnut showed the same pattern as peppermint, but peppermint oil is far easier to use at home.
The researchers noted limits. The tests took place in a lab, not in real homes, and it is not clear whether every household spider reacts the same way. Because these species tend to stay put as adults, the scent is more likely to keep spiders from entering an area than to drive out ones already settled.
How to Make a Peppermint Spray
Fill a spray bottle with about 2 cups of water and add 15 to 20 drops of peppermint essential oil, plus a small squirt of dish soap to help the oil mix. Some people use diluted white vinegar as a base instead of water. If you do, keep it away from natural stone and waxed wood, and never mix it with bleach. Shake well before each use.
Where to Use It
Spray where spiders get in and hide: window frames and sills, gaps around doors, corners of ceilings, behind furniture, under sinks and around vents. Test a small, hidden area first on painted or delicate surfaces.
Essential oils can be harmful to pets, especially cats, so avoid spraying where animals sleep or eat, and keep the bottle out of reach of children.
How Often to Reapply
Scents fade quickly. Reapply every few days, and after cleaning or rain, especially during the fall peak.
Habits That Keep Spiders Away
Spiders follow food, so reducing other insects helps. Seal cracks around windows and doors, repair torn screens, and turn off outdoor lights or switch to yellow bulbs, which attract fewer insects. Vacuum corners and under furniture regularly, reduce clutter, especially boxes in basements and closets, and move woodpiles and plants away from the walls of your home.
Say goodbye to spiders, at least most of them. A bottle of peppermint spray and a few simple habits can make your home far less inviting this fall.