For disease and pest control in the garden it's recommended to hold your big guns in reserve. Your first, and often the only line of defense necessary for pest control is the meditative practice of regularly handpicking adult insects, and scraping egg masses, off leaves (especially the undersides). Drop bugs and scraped egg masses into a cup of soapy water. See Bugs to identify friend from foe. Some bugs are there to eat your enemies! You can also use Companion Planting to discourage pests, using plants such as marigolds, which repel insects with their musky smell.
If things get ahead of you, the next step up is a simple insecticidal castile soap spray. In combination with a mild potassium bicarbonate solution this will fight most pests along with many early fungal diseases. If these solutions aren't keeping the enemy at bay, stronger organic weapons such as BT Bacillus for caterpillars, Neem oil, or copper sulphate sprays for fungal diseases may be called for. But these solutions can stress your plants, so hold them for a pitched battle!
Pepper spray is used to discourage flea beetles and striped cucumber beetles.
Soak 2 tablespoons of ground red pepper overnight in gallon of water. Add 6 drops of dish soap --- a natural vegetable-based soap like castile soap, not an anti-bacterial soap --- and place the mixture in a spray bottle.
To make pepper spray using fresh peppers, chop 1/2 lb. hot peppers and soak overnight in a gallon of water. Add 6 drops of dish soap and put the mixture in a spray bottle.
Wearing goggles and gloves, thoroughly spray the plants. Pepper spray is an irritant that can cause a burning sensation in the eyes and on the skin, so it is best not spray on windy days.
Milk spray is used to treat powdery fungus.
In a spray bottle, mix:
1 part milk (whole, 2%, or skim milk will all kill the fungus);
1 part tap water.
Spray both the top and the undersides of the leaves, as both are affected by the powdery mildew.
Spray every 3 to 4 days until the white fungus is gone. You may also spray uninfected plants with the milk and water solution every 7 to 10 days as a preventative measure.
Insecticidal Soap Spray
An organic insecticidal soap spray can be purchased from any garden center or made up for any spare clean spray bottle. You can simply drop a bar of castile soap into water overnight. If you have unscented, liquid castile soap, you add a tablespoon of liquid soap to a quart of water. You can also add 1-2 tablespoons of oil to help coat leaves more effectively.
Spray the leaves lightly on both sides. Spray again after rain. It is a good idea to try the spray out on a couple of leaves to make sure you aren't doing any harm and have your proportions correct.
Mix 1 tablespoon potassium bicarbonate and ½ teaspoon liquid castile soap (not detergent) in 1 gallon of water. Spray liberally to all affected areas. Apply once a week for three to four weeks.
This solution acts both as a treatment of existing powdery mildew infections and as a preventative measure.
Diatomaceous earth can be used to treat flea beetles. It is a white powdery substance and you should wear a mask when treating your plants with it.
Neem oil can be used to treat flea and cucumber beetles, as well as powdery mildew.
BT Bacillus can be used to treat tomato hornworms.
Serenade Disease Control
Serenade can also be used to combat powdery mildew.
Apply to established gardens at the start of the season and also in July.
An organic liquid fertilizer ( a fish or seaweed emulsion) can be applied directly to the foliage of plants and the plant leaves will absorb nutrients immediately. Follow the instructions for mixing with water then water each plant directly. This type of fertilizer can be used every time you water your plants.
Granular All-Purpose Fertilizer
Distribute this throughout your entire plot as directed on product label, avoiding direct contact with foliage. You can then lightly scratch the granules into the surface for better absorption. This is a slow acting remedy that should be applied every 4 weeks.