What little green worm is eating my kale?


My kale is getting eaten by a little green worm and there appears to be eggs on the plant as well. Do you know what this is and what I can do about it?


Jonathan Foster, Special Projects Assistant

There are several types of caterpillars that prey on brassica/cole crops like kale, with cabbageworms and cabbage loopers being the most common (I will include a link below to help you figure out which you have, but the control methods are the same, regardless). These caterpillars are the larval forms of adult moths that laid their eggs on your plants earlier in the season. The good news is that most cole crops tolerate light to moderate feeding, with a little help from the home gardener, though heavy infestations can kill the plants or leave the harvest not worth the hassle.

Hand picking the caterpillars and dropping them into a bucket of soapy water is the easiest and most effective method of control, though you will have to search your plants diligently as the pests like to hide down in the axils of leaves. Plus, their natural camouflage is extremely effective and they can easily be overlooked as you’re scouting the crop. The eggs you’re seeing *might* be eggs that haven’t hatched, but are more likely to be frass (i.e., excrement), which they produce copiously and which accumulates on the plant. For cultural control, next season you can start your crops under floating row cover, which will prevent the moths from laying eggs during the early months. Once that phase has passed, you can remove the row cover and continue on, hopefully caterpillar-free. The link below contains advice on chemical controls, as well, but that’s generally overkill for this sort of garden pest. If you do choose to use an insecticide, read carefully and follow conscientiously all instructions on the label. More is not better.

Once the caterpillars and frass have been removed/cleaned off, your kale is perfectly safe to eat, even if it’s chewed on or has holes.

Read more about these common pests on this great Univ of MN Extension page on caterpillars in cole crops.