KC Gardens: How do I get rid of caterpillars on herbs?
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? — Cindy
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 by handpicking. That is why it is very important to identify the pest first.
With caterpillars, I see two nontoxic options. The first one would be to handpick 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. BT breaks down rather quickly, especially in the heat.
However, you should read the label carefully regarding proper application and wait time before harvest. There is a four-hour wait period for re-entry to an area treated, but again read the label, as there are different formulations. I would try handpicking first. — Carole Brandt, Johnson County Extension master gardener
This Q&A has been edited for length. To read more on this topic or to get your gardening questions answered on The Star’s KC Gardens blog by Carole Brandt and other extension experts, go to KCGardens.KansasCity.com.
This story was originally published August 1, 2014 at 7:00 AM with the headline "KC Gardens: How do I get rid of caterpillars on herbs?."