Quick home remedies to control aphids and whiteflies on vegetables include garlic spray and tomato leaf spray. Diluted dish soap spray also works well for the control of these pests in the vegetable garden.
Tomato leaf spray is quick and simple to make. It has the advantage of only being toxic to soft-bodied pests, such as aphids and whiteflies, and doesn't harm beneficial insects, such as ladybirds. Chop 1 to 2 cups of tomato leaves, add 2 cups of water and let the mixture stew overnight. Use a sieve to strain out the tomato leaves and top it with another cup of water. Add the mixture to a spray bottle, and spray directly onto the stems and leaves.
Garlic spray kills all insects, so it is advisable to try the tomato leaf spray first. Mince four cloves of garlic, and add 2 teaspoons of mineral oil. Let it stand for 24 hours, then strain out the garlic, and add a pint of water and 1 teaspoon of organic dish soap to the oil and garlic mixture. To use, dilute 2 tablespoons of the mixture in 1 pint of water in a spray bottle, and apply to the leaves and stems.