I have been having trouble with caterpillars every year and I know the larvae is in the soil.I did some research and someone said to put hydrated lime in the soil in the fall.I did that and I did not have any trouble that year.What I was wondering if I put Diatomaceous Earth in the soil in the fall if that would work.That would be more organic than hydrated lime. What are your thoughts? If you have a better alternative I would appreciate it?
Certified GKH Gardening Expert
It probably would help to identify your caterpillars so you can ensure the best treatment. It's best not to randomly eliminate what's below the soil so as not to harm the beneficial earthworms.
Grubs are in the soil. I've included information on grubs as well as caterpillars.
There are uses for diatomaceous earth as insect control, particularly for slugs, snails, aphids in the garden. It is used on top of the soil to deter crawling pests or sprayed on the plants for aphids, etc. But caterpillars are not mentioned.
Caterpillar control is usually achieved with organic insecticides containing B.t. or spinosad.