Homemade spider repellents that use garlic, peppermint oil, citronella, tomato leaves, or tobacco and lemon can keep spiders out of the home, according to Pest Kill. These repellents work as a preventative measure when applied around doors and windows where spiders crawl into the house.
To repel indoor or outdoor spider infestations, two or three cloves of garlic with water in a spray bottle is effective. Five drops of citronella mixed with lemon dish soap and water keep both spiders and mosquitoes away. Dried cilantro seeds are suggested for keeping spider mites away from gardens.
Commercially available plug-in spider repellents also are available. These devices use ultrasonic sound waves to repel spiders.