It can be frustrating to put your time and heart into a garden, only to have it destroyed overnight by garden pests such as caterpillars. These creatures wreak havoc on vegetable and herb gardens, but there are ways to get them out and keep them out to ensure your garden grows back strong and pest-free. One of the most natural, least expensive and simplest ways is with citrus fruit juices, which contain limonoids that caterpillars can't stand.
Collect the rinds from four citrus fruits---orange, grapefruit, lemon, lime or tangerine. Finely chop them in a food processor.
Put the chopped rinds and juices in an airtight container.
Add about two cups of water to the container with the rinds, then shut it tightly and let it sit overnight.
Open the container the next day and pour the mixture through a fine strainer. You want to make sure the pulp and liquid separate. Next, put the liquid into a spray bottle.
Spray the mixture on the leaves, stems and blossoms of your garden plants and on the area around them. The limonoid particles from the citrus fruit will repel the caterpillars and keep them away.
Repeat this process after heavy rains or watering, until you notice that there are no pesky caterpillars bothering your vegetable garden.