Some natural ways to keep roaches away from a home include washing hard surfaces in the kitchen and bathroom with an ammonia-and-water solution once every two weeks. A tea of 1 tablespoon of catnip in 2 cups of water sprayed around the home repels roaches.
To make an effective natural roach repellent, mix 1 tablespoon of cayenne or red pepper, 1 clove of crushed garlic, a whole crushed white onion and 4 cups of water. Boil the water in a pot, and add the spice mash to the pot. Turn off the heat, allow the mixture to cool and pour into spray bottles. Spray this repellent around baseboards, in doorways, on windowsills or any areas where roaches may be hiding or entering.