It's best to start with the weakest dilution and work up to higher dilutions only if necessary, to avoid damaging the plants you are trying to protect.
1-Percent Dilution
The lowest effective dilution of detergent and water is 1 percent. This will kill some soft-bodied pests but may not be as effective as the more commonly used 2-percent dilution. To achieve a mixture of approximately 1 percent, add 2 1/2 tbsp. dish washing detergent to 1 gallon of water, and mix well. For smaller batches, if you do not need an entire gallon of solution, add 2 tsp. dish soap to one quart of water, or 1 tsp. dish detergent to one pint of water.
2-Percent Dilution
A 2-percent dilution is favored by many gardeners because it is less likely to damage plants while still killing most of the intended insects. A dilution of approximately 2 percent can be created by mixing together 5 tbsp. of dish washing detergent and 1 gallon of water. For smaller batches of a 2-percent dilution, mix 4 tsp. dish detergent with 1 quart of water. Single application mixes can also be made by combining 2 tsp. dish detergent with 1 pint of water.
3-Percent Dilution
Sensitive plants, like tomatoes, are more likely to be damaged by a 3-percent dilution, so it's important to test this mix out on a single leaf or small portion of the plant prior to a full application. This stronger mix is better at killing soft-bodied arthropods, however, like the aphids that tend to attack tomato plants. To create a solution that is approximately 3 percent dish detergent, mix 8 tbsp. of dish soap with 1 gallon of water. Amounts for smaller mixtures of a 3-percent dilution are 2 tbsp. dish soap mixed with 1 quart of water, or 1 tbsp. dish soap combined with 1 pint of water.
4-Percent Dilution
The strongest recommended dilution is 4 percent. Although it is advisable to test a mixture of any strength before use, it's especially important when using the highest dilution. Even plants that aren't typically sensitive to dish soap pesticide control could react to a 4-percent dilution, especially if it's applied regularly. For a mixture that is approximately 4percent, mix 10 tbsp. of dish washing detergent with 1 gallon of water. Smaller batches can be mixed at a rate of 2 1/2 tbsp. dish detergent in 1 quart of water, or 4 tsp. dish detergent in a pint of water.
The Drip Cap
- Dish washing detergent mixed with water is an effective way to kill some plant pests while avoiding the hazards of pesticides.
- dish soap to one quart of water, or 1 tsp.
- dish detergent to one pint of water.
- A 2-percent dilution is favored by many gardeners because it is less likely to damage plants while still killing most of the intended insects.
- A dilution of approximately 2 percent can be created by mixing together 5 tbsp.
- Sensitive plants, like tomatoes, are more likely to be damaged by a 3-percent dilution, so it's important to test this mix out on a single leaf or small portion of the plant prior to a full application.
- of dish washing detergent with 1 gallon of water.