Marigold, petunias and white geraniums are said to help ward off harmful nematodes, cutworms, beetles and tomato hornworms.
Keep tomatoes away from all members of the cabbage family and always plant dill and tomatoes at opposite ends of the garden.
Aphids, a common problem for tomatoes, peppers and fruit trees, are a natural food source for hover flies and ladybugs. To attract hover flies plant plenty of parsley throughout the garden
Onion chives help repel pests such as tomato horn worms, red spider mites and aphids from tomatoes.