It's been widely known that mixing worm compost or "vermicompost" into soils growing flower and vegetables will reduce plant diseases and add significantly more nutrients to the soil than regular compost. Now, research at the Ohio State University Soil Ecology Laboratory suggests that vermicompost can suppress insect damage as well.
Researchers grew tomatoes, peppers, and beans in a greenhouse; some of the plants were grown in pure potting mix, while others were grown in potting mix containing either 20 or 40 percent vermicompost. All plants were exposed to aphids, spider mites, and mealybugs. The plants grown in the vermicompost pots showed significantly less insect damage than those grown in plain potting soil. Researchers speculate that the vermicompost may change the composition of the plant tissue, making it less attractive to the insects.
While more research is needed to further understand the mechanism of vermicompost's effect on plants, it's clear that adding worm compost to your containers and garden will aid your plants in many ways.
For more information, go to this article about the vermicompost research.
Article published on June 23, 2008.