KC Gardens

What to do about bug-eaten herbs?

Basil caterpillar
Basil caterpillar Submitted photo


This is the first year I’ve tried growing herbs on my deck. They’re pretty big but they’re also getting eaten up by bugs. I know I shouldn’t use anything toxic so what should I do? Thanks - Cindy


So sorry, but it would be hard to say. First, what herbs are you growing? Second, try to identify the insect. Look on the underside of the leaves, and along the stems. If you don't see any insects, do you see any webbing or blackish dots on the undersides. Is the entire leaf being eaten, or just the edges, or are there holes in the inner part of the leaf? Are the leaves spotty, discolored? And, since the herbs are in pots, search in the pot's soil too.

You are correct in that you do not want to use any chemicals. Sometimes a pest can be eliminated with a strong jet of water, or simply by handpicking. That is why it is very important to identify the pest first.

Please post back with your findings, and a picture would be great.


Johnson County Extension Master Gardener


Okay, here are photos of caterpillars on basil and mint. - Cindy


Thanks for the photos. With caterpillars, I see two non-toxic options. The first one would be to hand pick the caterpillars, then search for the eggs and wipe them off the plants. The second option is to use BT (one brand is Dipel, but there are others), which is rated as a biological control for caterpillars. BT is short for Bacillus thuringiensis and it is rated as organic. I looked at the listed crops on the Dipel website, and mints and herbs are listed. BT breaks down rather quickly, especially in the heat. However, you should read the label carefully regarding proper application and wait time before harvest. What I gleaned is that there is a 4 hour wait period for reentry to an area treated, but again read the label as there a different formulations. Personally, I would try handpicking first. Cindy, your detective work was excellent. Good luck.