There are of course no foolproof methods - These ideas and tips are examples of what has worked for the garden at Diana's in Hubbard, Ohio and that of friends/family over the years.
Use your own discretion & common sense. If you have an allergy to something - do not use it.
1.) Orange (citrus) Peel Spray
Oranges (citrus fruits) contain natural pesticide compounds called limonene and linalool.
Can be used against soft bodied pests = aphids, fungus gnats, mealy bugs and as an ant repellant.
Pour 2 cups boiling water over one orange peel. Let this steep 24 hours. Strain liquid into a jar (compost peel). Use liquid as a spray mixing in a few drops of a natural soap on insects.
2.) Marigold Spray
Known to repel asparagus beetles, tomato hornworms, leaf cutting and chewing insects.
Directions: Mash 1 cup of marigold leaves and flowers. Mix with 1 pint of water.
Let soak for 24 hours. Strain through cheesecloth. Dilute with 1 1/2 quarts of water then add 1/4 teaspoon of castille (or any Natural) soap and spray affected areas.
3.) Lime Spray
Target insects: Cucumber beetles, mites and general purpose.
Mix 1 ounce of hydrated lime, 1 quart warm water and 1 teaspoon of castille (any NATURAL soap). Use up to twice a week.
4.) Horseradish Natural Pesticide
Aphids, blister beetles, caterpillars, Colorado beetles, whiteflies, soft-bodied insects Possibly slugs.
Bring 3 quarts water to a boil, add 2 cups cayenne (any hot) pepper, a 1 inch piece horseradish root -fresh/chopped, and 2 cups scented geranium leaves, any kind. Let steep for 1 hour, cool, strain and spray. * Can be made without the scented geranium leaves if you don't have them.
5.) Elder Leaf Natural Insecticide:
Aphids, carrot root fly, cucumber beetles, peach tree borers, root maggots and midges.
Elder leaf has fungicidal properties so may be useful against mildew and blackspot diseases.
Simmer 8 ounces of (elderberry) leaves in 1 pint of water for 30 minutes. Stir thoroughly, then strain. Take 16 oz. of warm water and mix with 1 tablespoon of castille soap (any natural soap). Add soap mixture to the elder water, spray as needed. * Set your sprayer to apply large droplets as this mixture will plug up a sprayer at the fine setting.
6.) Garlic Spray
For: Aphids, cabbage loopers, grasshoppers, June bugs, leafhoppers, mites, squash bugs, slugs and whiteflies. May also help to repel rabbits! * Never use oil sprays on Blue Spruce as it will remove the blue waxy coating on the needles! Garlic contains naturally occurring sulfur so it can also act as an antibacterial agent and fungus preventative.
Directions: Throw a handful of garlic into a blender wtih 1 quart of warm water, let steep a few hours, strain out the solids and spray onto the pests. Also spray the plants as a preventitive.