Cabbage Moth Destruction:
By now, you have all experienced the sometimes very severe damage that the cabbage worm causes to your plants. The cabbage worm is a caterpillar that is part of the life cycle of the white cabbage moth. The moth lays its eggs on the leaves and out come the little caterpillars who munch away and make holes in your leaves, sometimes completely defoliating the plants to the skeleton. This cabbage worm/caterpillar then turns into the pretty white moth you see floating around your garden, and the cycle starts all over again.
All members of the Cole family/Brassica family are affected, and the only way to control the cabbage worm is to spray BT. This natural basilis comes in two forms that are commercially available. One is called Dipel Dust and the other is in a liquid form, simply called BT. The liquid form of the BT is diluted with water at 4 tablespoons per gallon, which will treat up to 8 beds of brassica plants; a 1/2 pound bag of Dipel dust will do the same, simply dust it over the plants. You apply both products when the plants are dry and you are not watering, at any time of day, which allows the substance to be ingested by the caterpillars. At this point, you need to apply BT about twice a week and remember any rain or watering will wash away both dust and liquid.
Members of the Brassica family that are affected by the cabbage worm include: cabbage, Chinese cabbage (Napa), tatsoi, bok choy, broccoli, cauliflower, and kohlrabi.
This autumn the cabbage worm damage seems to have gotten exacerbated by the flash drought we experienced during August and the first part of September. This lack of rain left our lushly watered vegetable patches highly appealing, and all of the pest damage seem to have focused on our Brassica crops.
If you take these steps, your Brassica crops should bounce back, but if they don’t please contact Lauren Blood (firstname.lastname@example.org) for help.