Here is what we found:
The pest: Cabbage Worm (the imported cabbage worm)
These insects are popularly found on leafy greens such as cabbage, kale, lettuce, arugula, and radishes.
They develop into a white, or pale yellow butterfly with a black dot on each wing.
Early Prevention:
- They have many natural predators, such as spiders, beetles, and birds. Make sure not to hinder these from entering your garden.
- Protect plants early with floating row covers so butterflies don’t lay eggs on the leaves.
- Wasps, although thought of as pests themselves, may help by seeking out the eggs laid by the butterflies. Do not kill off your local wasps!
- Herbalists recommend planting tansy plants near your kale, lettuce, or arugula. This has a volatile oils that deter butterflies and moths from laying there eggs. We hope to try this next year with our theme “Companion Planting”.
During an Outbreak:
- Chickens and Ducks may be helpful in eating all the cabbage worms off your plants (if you have access to them!)
- When cabbage worms are first seen, pick them off as soon as possible to allow for the decrease in spread of these pests
- Once worms are apparent, apply Garden Dust to leaves where they’re seen. This naturally occurring soil bacteria, listed for organic use by the Organic Materials Review Institute, will take out the worms as they feed.
- Botanical insecticides may be useful tools for an organic garden, but remember that these are still toxic and should be used after other measures have failed to work.
- The worms may also move to garden borders and margins. Keep areas around your garden clean, so they don’t spend the winter there!
Written by Grow La Crosse intern Cody Sromek
