Someone’s eating my plants, and it’s not me!
Have you noticed big pieces of your plants missing? Those holes are likely evidence of cabbage white butterfly larvae, who love to munch on plants in the brassica family, including kale, collard greens, cabbage, broccoli and cauliflower. The fuzzy green worms blend in with the leaves, and can range in size from 1/4″ when they are very young, to over an inch long!
They’re usually on the tops of leaves during the day, and are often resting on the leaf “vein”, where they blend in best. The most reliable method for keeping them from eating your plants is to pick them off by hand, and then place in a bag that gets sealed and discarded. You can also squish them on site! To prevent them from getting on your plants in the first place, you can drape a floating row cover- which is a lightweight specialty fabric- over the bed. You can also try inter-planting strong-smelling herbs and edible flowers, such as dill, fennel and basil near your plants, to help repel the adult cabbage white butterflies so they don’t lay eggs on your plants.
Be sure to check under the leaves for their eggs and remove those as well. Don’t confuse frass, or poop, for the eggs or you won’t be making much of a dent in the population on your plants! You can also look out for chrysalises- the pupal form, under the leaves. Although it may seem harsh, it’s also a good idea to destroy these as well. When the pupa emerges as a cabbage white butterfly, it can lay large numbers of eggs, which will continue the cycle of eating plants in your garden!