Horseradish Spray

2 cups of cayenne peppers
1 inch piece of chopped horseradish root
2 cups of packed scented geranium leaves, any kind (optional)

Bring 3 quarts of water to a boil, add cayenne peppers, horseradish root, and geranium leaves. Let steep for 1 hour, cool, strain and spray.

Controls: Aphids, blister beetles, caterpillars, Colorado beetles, whiteflies and soft-bodied insects. Maybe even slugs.

Lime Spray

1 ounce of hydrated lime
32 oz of water
1 tsp of castille soap

Mix lime, water and soap. Use up to twice a week.

Controls: Cucumber beetles, mites and general purpose.

Marigold Spray (Calendula officinalis)

1 cup of marigold leaves and/or flowers
1/4 tsp of castille soap

Mash marigold leaves and flowers, mix with 1 pint water. Let soak for 24 hours. Strain through cheesecloth.
Dilute this with 1 1/2 quarts of water then add soap. Spray target areas.

Controls: Repels asparagus beetles, tomato hornworms, leaf cutting and chewing insects, like leaf cutting bees on your roses and lilacs.

Nicotine Spray

Soak 1 cup of dried, crushed tobacco leaves, or an equivalent amount of cigarette butts, in one gallon of warm water with 1/4 tsp pure soap added. Strain the mixture through cheesecloth after it has soaked for 1/2 hour. The solution will keep for several weeks if stored in a tightly closed container. Soil pests, pour onto the soil in the area of the stem base and root zone. Leaf pests, spray leaves thoroughly, especially the undersides. Use only on young plants and only up to one month before harvest. It's probably safest not to spray nicotine on eggplant, peppers or tomatoes. While most tobacco cultivars now grown are resistant to tobacco mosaic virus, nicotine sprays could contain the pathogen, which will infect nightshade family crops (tomatoe, potatoe etc.).

Controls: effective against ground and soil pests, especially root aphids and fungus gnats, and on many leaf-chewing insects, such as aphids, immature scales, leafhoppers, thrips, leafminers, pear psylla, and asparagus beetle larvae.

Orange Peel Spray

Pour 2 cups of boiling water over peelings from one orange. Let this steep for about 24 hours. Strain into a glass jar. Mix in few drops of castille soap and spray on target insects or on ants and their nests.

Controls: soft bodied pests such as aphids, fungus gnats, mealy bugs and as an ant repellant.

Pepper Spray

2 tbsp red pepper (store bought dried)
6 drops dish soap
1 gallon water

Mix all ingredients, let sit overnight and stir to dissolve as much of the pepper as possible. Spray mixture around plants weekly to repel insect pests.

1/2 cup of finely chopped or ground hot peppers (fresh or whole dried)
1 pint of water

Mix hot peppers with water. Let sit 24 hours. Use as is for a soil drench or strain through cheesecloth until you have a clear liquid. Add a few drops of castille soap and use as a foliar application. Keep away from your eyes and skin.

Controls: general purpose

Pyrethrum Daisies

The concentration of pyrethrums is at its peak when the flowers are in full bloom, from the time the first row of florets open on the central disk opens to when all the florets are open. Pick flowers in full bloom and hang them in a sheltered, dark spot to dry. Once the flowers have dried thoroughly, grind to a fine powder, using a old blender. Mix with water and add a few drops of liquid soap to make it stick. Store tightly closed in a glass jar, the mixture looses activity if left open. Because the concentration of pyrethins in the flowers is an unknown variable you will have to experiment with the amount of water to add. If the spray you make does not seem to kill insects, use less water the next time you make the concentrated spray. Also keep in mind whole flower heads stay potent longer, do not grind until ready to use. For best results, apply in early evening, pyrethrins are more effective at lower temperatures. Spray upper and lower surfaces of the leaves, spray must directly contact the insects. Can be applied up to one day before harvest. Toxic to fish and to the aqautic insects and other small animals that fish eat.

Controls: effective on many chewing and sucking insects, including most aphids, cabbage loopers, celery leaftiers, codling moth, Colarado potaotoe beetles, leafhoppers, Mexican bean beetles, spider mites, stink bugs, several species of thrips, tomato pinworms, and whiteflies. they are especially good against flies, gnats, mosquitoes, and stored products pests. Flea beetles are not affected, nor are imported cabbageworms, diamondback moths, pear psylla, and tarnished plant bugs.

Sugar Drench

Mix 1/2 a cup of sugar with 1 gallon of water. Stir to dissolve sugar. Pour on the soil around plant roots where you have had nematode problems or use as a treatment prior to planting.

Controls: Bad nematodes! Sugar also adds trace minerals to the soil.

Tomato, Potato Leaf Spray (nightshade family)

Soak 2 cups of chopped tomato or potato leaves in 1 pint of water overnight. Strain then add another pint of water and 1/4 tsp of castille soap to make it stick. Spray foliage and soil as needed.

Controls: Repels asparagus beetles and flea beetles.This will kill earworms and maggots and acts as an antifeedent for other insects. For aphid control, be sure to thoroughly cover the leaf undersides, especially of lower leaves and growing tips of plants where aphids congregate
Attracts benifical insects such as Trichogramma wasps

Wormwood Spray

8 oz wormwood leaves
4 pints of water
1 tsp castille soap

Simmer wormwood leaves in the water for 30 minutes. Stir, strain, and leave to cool.
Add the castille soap to wormwood mixture and use to spray.

Caution is advised when using wormwood sprays around plants as it can inhibit growth.
Controls: Aphids, caterpillars, crawling insects and slugs. May repel snakes.

Resources: Rodale's Chemical-Free Yard and Garden
Rodale's The Encyclopedia of Natural Insect and Disease Control.