There are of course -no foolproof methods.
The ideas and tips shown here are examples of what has worked for the garden at Diana's in Hubbard, Ohio and that of friends/family over the years.
Please use your own discretion and common sense.
1.) Orange (citrus) Peel Spray
Oranges (citrus fruits) contain natural ocurring pesticide compounds called limonene and linalool. This can be used against soft bodied pests such as aphids, fungus gnats, mealy bugs and as an ant repellant.
Directions: Pour 2 cups of boiling water over one orange peel.
Let this steep 24 hours. Strain the mixture into a jar and compost the peels. Use this liquid as a spray mixing in a few drops of a natural soap on target insects.
2.) Marigold Spray
Target insects: 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 other Natural) soap. Spray target areas.
3.) Lime Spray
Target insects: Cucumber beetles, mites and general purpose.
Directions: Mix 1 ounce of hydrated lime, one quart of warm water and 1
teaspoon of castille (any NATURAL soap) soap. Use up to twice a week.
4.) Horseradish Pesticide
Target insects: Aphids, blister beetles, caterpillars, Colorado
beetles, whiteflies and soft-bodied insects. Possibly slugs.
Directions: Bring 3 quarts of water to a boil, add 2 cups of cayenne (any very hot) peppers, a 1 inch piece of chopped horseradish root -fresh, and 2 cups scented geranium leaves, any kind. Let the mix steep for 1 hour, cool, strain and spray. * This can be made without the scented geranium leaves if you don't have them.
5.) Elder Leaf Insecticide: 
Target insects: Aphids, carrot root fly, cucumber beetles, peach tree
borers, and root maggots. It is particularly effective against
midges. Elder leaves also have fungicidal properties and may be
useful against mildew and blackspot diseases.
Directions: 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
Target insects: Aphids, cabbage loopers, grasshoppers, June bugs,
leafhoppers, mites, squash bugs, slugs and whiteflies. May also help
to repel rabbits! * Never use oils 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.
