Every spring, little white butterflies flutter in the garden visiting all the spring flower. They look so pretty and unassuming, so lovely among the lilacs.
Then the kale comes up, beautiful dark green and lush. Dreams of sausage and kale soup settle in your brain. You head to the garden with a bowl and scissors, whistling a happy song. Then you notice the holes. Your beautiful kale has been chewed to a skeleton. Little light green caterpillars are hiding under the leaves, trying to look like they didn’t steal your food.
Your garden has been invaded by Cabbage Moths. An adult female lives for 3 weeks and during that short time can lay 300-600 eggs. You’ll find tightly packed bunches of yellow eggs on the underside of the leaves. They hatch in about a week and then set about to devouring your kohlrabi and broccoli for the next two weeks unless you catch the little buggers and do away with them. If that wasn’t enough bad news for one paragraph, there can be up to 10 generations of moths in a single growing season.
The best control for these greedy things is to set up a healthy habitat in your garden with plenty of birds and beneficial insects like Green Lacewings, parasitic wasps and yellow jackets. Trichogramma wasps are especially fond of nice plump larvae for laying their own eggs.
Floating row covers can keep the moths away from your veggies in the first place. If they can’t get on your chard, they can’t lay eggs.
Tansy is a natural repellant for cabbage moths as well as a medicinal herb. Plant it in between your brassicas to keep them at bay or spray tansy tea on the leaves. Make sure to get the tops and bottoms.
Inspect the plants and pick off the larvae by hand. Drop them in a bucket of soapy water.
Use a biological spray to keep the moths away. There are several commercial varieties or you can whip up a batch of chili-garlic sauce that these insects hate. My husband swears by simple salt water.
If you’ve got poultry, they love a little cabbage moth larvae buffet. Don’t let them hang out too long though or they start dining on your cabbage too.
Some gardeners recommend clearing all the debris from around your veggie beds to deprive cabbage moths from their cozy winter lodging. However, removing all the leaves and stems from the beds means that the soil loses all the nutrients from rotting vegetation. Your call on that one. For me, composting in place has a better ROI.