Most people start with a can of peppermint spray, and that is not a bad instinct. It just solves a smaller problem than the one you have. Spiders are in the house because something else got in first, and no spider repellent changes that. To reduce the numbers indoors, remove the food and close off entry points. Then you clear out the spiders that have already moved in. Here is what works in a Southern California home, and what doesn't.
Why Are There Spiders in My House?
Food. Almost every time, food. Spiders are predators, and a house with spiders is a house with something for them to eat: gnats around the sink, moths at the porch light, ants tracking along the baseboard. Clear out the insects, and the spider population drops on its own.
Moisture is the second draw. Bathrooms, laundry rooms, and the shaded side of a house hold humidity longer than the rest of the structure, and both spiders and the insects they hunt gather there.
Then there is October. Fall is when spiders are most noticed across the Inland Empire, and it is not because the population spiked. The males that matured over summer leave their webs and wander looking for mates, so they end up crossing a living room floor at nine at night in full view. Our post on why spiders show up at night covers that pattern.
Do Natural Spider Repellents Work?
A little, at best, and only for a short time. Peppermint oil may make some spiders avoid a treated spot while the scent is strong, but the research on it is thin, and there is even less behind citrus or vinegar sprays. Whatever effect there is fades fast. A few days of Southern California sun on a windowsill and it is gone, so you keep re-treating and still haven't addressed why they came in.
Diatomaceous earth behaves differently. It is a fine powder that damages the outer layer of crawling insects that walk through it. It works only while it stays completely dry and only where something walks over it, and spiders pick up less of it than insects do (more on that below), so its real value is cutting down the insects spiders feed on.
Spread it across a whole floor and you get a mess and no result. A thin line in the back of a garage corner is a fair use of it.
Here is how the common options stack up:
Scent sprays (peppermint, citrus, vinegar): short-lived and unproven, a spot deterrent at best
Diatomaceous earth: works dry, in tight spots, applied thinly, and better on the insects spiders eat than on spiders
Sticky traps in corners and behind furniture: good for showing you what is around, not for control
Ultrasonic plug-in devices: no effect worth paying for
One thing worth knowing about spiders specifically. They walk on the tips of their legs and hold their bodies higher off the surface than insects do, so they pick up less spray residue when they cross it. A product that wipes out ants along a baseboard can leave a spider walking the same baseboard untouched. That's why even the best spider repellent spray on the shelf tends to disappoint.
Which Spiders Matter in Southern California?
Most of what you find indoors here is harmless. Cellar spiders in garage corners and the occasional wolf spider that came in under a door are nuisance-level. They do not need a treatment plan; they need a cup and a piece of paper.
Two are worth identifying properly, and our post on widow spiders in California covers both in more detail. Black widows sit in undisturbed low spots: under patio furniture, inside a stacked woodpile, in the rim of an outdoor meter box.
Brown widows have become very common across Southern California and behave much the same way; their egg sac is the giveaway, covered in small spiky points rather than smooth. Both sit where hands go without looking, and that is the real risk.
If you are worried you are looking at a recluse, go through our post on brown recluse spiders in California, because that identification rarely holds up in this state. For everything else, the rundown of common California spider species will get you to a name.
How Do You Stop Spiders From Getting In?
Indoor spider control is mostly outdoor work, since most spiders inside come from the strip of ground right outside the wall.
Start with the lights. A porch or landscape light burning all evening pulls in moths and midges, and spiders set up webs to eat them. Switch to warm-toned bulbs or move the light away from the door to cut down the insects gathering there.
Then clear the ground right against the house. Woodpiles, stacked pots, and dense ground cover pressed against the base of the wall give spiders somewhere to live within a step of the door. Pull them back a foot and a half and spiders lose that cover.
Sealing matters, though not in the way people expect. Spiders squeeze through openings far too small to spot casually, so caulking every crack is a losing game. Focus on the ones that carry real traffic:
Door sweeps, the strip along the bottom of a door, especially on the garage side door
Torn window screens and the frame edges around them
Where pipes and wires pass through the exterior wall
Weep holes, the small drainage openings in brick walls, and any uncovered vent
Inside, run a vacuum along ceiling corners and behind furniture, then take the bag or canister straight outside. That removes egg sacs, which can each hold dozens to hundreds of eggs and which sprays do little to. Sticky traps set flat against a garage wall will tell you whether numbers are dropping.
When Should You Call a Professional?
The deciding factor is whether the same thing keeps happening after you have done the work. If you cleared the ground against the house and changed the lighting, but you still find fresh webs in the same room three weeks later, something is feeding them that you haven't found.
Call sooner if widows are involved and the spot is somewhere your family reaches blind: a child's play structure, a barbecue cover, the underside of patio seating. That one is not worth working out yourself.
On a spider service, we knock down and remove existing webs and egg sacs by hand, treat the outside edges of the house and the tucked-away spots where spiders actually rest, not the open surfaces they rarely touch, and target the insect activity that brought them in.
Then we tell you which two or three things around the house are still pulling them back. Our full residential and commercial pest control services cover the insect side of it at the same visit, because treating spiders without treating their food is how you end up calling again in spring.
Still Finding Spiders? Call ProCraft
Spider sightings peak in fall in Upland and Rancho Cucamonga and ease off as winter sets in. A widow population in the side yard does not go away with the season, and neither does an insect problem feeding webs in the garage.
We are family-owned, licensed in California, and the certified Service Technician who shows up lives here. Free estimates, flat pricing, and a callback service if anything comes back. Call us at (626) 681-4120 or contact ProCraft Pest Control.
Spider Control Questions We Get
Does peppermint oil actually repel spiders? It may repel spiders a little while the scent is strong, but the research is thin, and the smell fades within days, faster outdoors. Treat it as a spot deterrent for a windowsill or doorway, not as a control method.
Is spider spray safe around pets and kids? The products we use dry quickly, do not stain, and are safe around family and pets once dry. We will tell you exactly how long to stay off a treated area before we leave.
Why do I see more spiders in fall? Males that grew up over summer leave their webs in the fall to look for mates, so you see them crossing open floors instead of sitting in a corner. The population did not spike; the visibility did.
Will one treatment get rid of spiders for good? No single treatment does that. One visit removes the webs and egg sacs present and brings numbers down. Keeping them down depends on lighting, the ground against the house, and whether their food comes back.
How do I get rid of spiders in my garage? Pull stored items off the floor and away from the walls, vacuum the ceiling corners and egg sacs, and fix the side door sweep. In most Southern California homes, the garage is where indoor spider control starts.
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