A mixture of garlic, onion, cayenne pepper, water and liquid dish soap makes an effective garden insect spray. To make, liquefy one garlic clove and one small onion. Mix with 1 teaspoon of ground cayenne pepper, 1 quart of water and 1 tablespoon of liquid dish soap.
WellnessMama.com offers witch hazel- and vinegar-based insect repellents for personal use mixed with either essential oils or dried herbs. To prepare the essential oil recipe, pour 4 ounces of distilled water into an 8-ounce spray bottle and fill almost to the top with witch hazel. Add 30 to 50 drops of essential oils. WellnessMama.com recommends using a mixture of rosemary, clove, cajeput, lavender, cinnamon and eucalyptus.
If using herbs, choose a mixture of peppermint, spearmint, citronella, lemongrass, catnip and lavender. Bring to a boil 1 cup of water mixed with 3 to 4 tablespoons of dried herbs plus two whole cloves. Cover, remove from heat and let cool. Strain the water and pour into an 8-ounce spray bottle. Add 1 cup of witch hazel or rubbing alcohol. Store this version in the refrigerator.
For a very strong insect repellent concentrate, mix 32 ounces of apple cider vinegar with 2 tablespoons each of dried sage, rosemary, lavender, thyme and mint. Seal in an airtight glass jar and shake well every day for two to three weeks. Strain the vinegar and store in the refrigerator. To use the concentrate, mix half concentrate and half water in a spray bottle. The smell dissipates when dry.