Hot Dusts

Black pepper, chili pepper, dill, ginger, paprika, and red pepper all contain capsaicin which has been shown to repel insects.

Grow and dry your own red peppers, chili peppers, or dil. Use a mortar and pestle to grind the peppers, or dill, including the seeds, to dust. Sprinkle along seeded rows of onions, cabbage, or carrots, in a band at least 6 inches wider than the row or planting bed. A fine sprinkling will work, but the more dust you use, the better the effect. Renew after a heavy rain or irragation. To protect plants from ants, sprinkle around the base of plants in an area as wide as the widest leaves.

Controls: repels onion maggots from seedlings, as well as other root maggot flies from cabbage family plants and carrots. Pepper dusts around the base of the plants help repel ants, which is desirable in a garden where ants often protect and maintain aphid colonies on plants.

Ants

Locate their hill and sprinkle a liberal amount of talc powder around and on it. The ants dislike the talc and will move their colony several feet. Just continue sprinkling with the talc until the ants are moved to where you want them, a twist on 'capture and relocate'.

Straight vinegar deters ants. Spray around doors, appliances and along other areas where ants are known.

Black Spot

In a sprayer mix 1 gallon water and 3 Tbsp baking soda. If severe add 1 tbsp of copper hydroxide. Spray every three days, may also add to soaps as above. Make sure you pick up fallen leaves and get rid of them (NEVER compost them) they contain the spores.
See also Elder Leaf Spray

Blisters on Geranium Leaves

is a condition called edema and may be caused by a boron deficiency. Mix 1/8 teaspoon borax into 1 gallon of water and use it to water the plants two or three times.

Cutworms

Cutworms attact young seedlings at the ground level.

Cut an empty toilet paper roll in half. Carefully place collar over newly emerged seedling or new transplant. Press into the soil carefully.

Cut a plastic drinking straw into 1-2 inch sections, split it down the side and wrap around seedlings making sure you press it to below ground level. There is more chance of damage to the young plants applying it, but if your very careful you should do fine. The split should prevent it from choking the plant as it grows.

Dogs and Cats

To keep them out of the garden, steep together for 1 hour
1 chopped garlic bulb
1 tbsp of cayenne pepper
1 quart of water

Add
1 tsp liquid dishwashing soap
Strain off the amount you need and sprinkle it onto plant leaves. Store the remainder refrigerated in a covered jar, will keep for several weeks.

Deer - Keeping them away from fruit trees

Take several pounds of soft scented herbal soap and form it into balls, tie into small bundles using net string or cloth. Hang several of these bundles from each tree you want to protect. It not only repels deer, as it rains and melts the soap it adds source of alkalinity to the soil.

Japanese Beetles

Open a can of fruit cocktail and let it sit in the sun for a week so it ferments. Then place it on top of bricks or wood blocks in a light-colored pail filled to just below the top of the can with water. Place about 25 feet from the plants you want to protect. Beetles will head for the sweet bait, fall into the water, and drown. If it rains and dilutes the bait replace it with a new can (fermented first).

Mites

Mix 1/2 cup of buttermilk, 4 cups of wheat flour, and 5 gallons of water, strain the mixture through cheesecloth. Spray it onto affected plants to kill both the mites and their eggs.

Mosquitos

1 cup lemon scented dish soap
1 cup lemon scented ammonia
Set hose end sprayer to 20 gallons, spray three times a week.
Mosquito breeding in rain barrels:

1 tbsp of olive oil added to rain barrels will prevent mosquitoes from breeding.

Powdery Mildew

1 part milk with up to 9 parts water. Spray every three days.

1 bulb (aprox 20 cloves) garlic finely chopped, mixed with 1 quart hot water and allowed to steep at least 24 hours. Strain and spray every three days for fungis and powdery mildew until it is eliminated.

Radish Maggots

Sprinkle wood ashes over seeds before covering with soil.

Rabbits

Dust plants with plain talcum powder. It also repels flea beetles on tomatoes, potatoes, peppers, and other plants.

Slugs and Snails

Place beer in a shallow pan/saucer with edges even with the ground. Snails and slugs will crawl in for a taste, and drown.

Bake egg shells in an oven to harden and then place around plants to prevent slugs damaging them. The slugs cannot get over the sharp edges of the hardened shells.

Sand, Lime, or Wood Ashes.
Sprinkle around plants, snails avoid protective borders of sand, lime, or ashes. Ashes are a good source of potassium and unlock nutrients so that plants can take them up.

Thrips on Gladiolus

Soak gladiolus corms in 1 tbsp Lysol and 1 gallon of water. Plant corms while still wet.

Whiteflies

Whiteflies are attracted to the color yellow. You can trap them with yellow index cards or plastic containers coated with petroleum jelly, they will stick to the petroleum jelly and die.

Apple Tree Pest Trap

1 cup of vinegar
1 cup of sugar
1 quart of water

Mix and pour into a widemouthed plastic jug. Hang the jug, uncovered, in each apple tree.

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