RECIPE #32 PEST DETERRENT WITH VITAMINS Categories: Garden, Pests Studies at the University of Wisconsin at Madison by entomologist Dale Norris have shown certain pests are repelled when plants sprayed with a vitamin solution. Specifically vitamins C and E were sprayed with microscopic dosages on soybean plants and then offered to cabbage loopers. The loppers shunned the sprayed plants and opted for unsprayed plants. According to Norris the vitamins will work on houseplants, cantaloupes, tomatoes, geraniums, cabbage, cauliflower, sweet corn and broccoli. There are no products available on the market yet. But you could try brushing a 500 milligram vitamin c tablet and dissolve it in five gallons of water to test the theory out yourself.